th The 9 International Conference on Nanophotonics (ICNP 2016)
Time March 21-25, 2016. Location Humanities and Social Science Building (HSSB), Academia Sinica ICNP 2016
The 9th International Conference on Nanophotonics
March 21-25, 2016 Academia Sinica, Taipei, Taiwan
Sponsored by
Department of Physics, National Taiwan University Department of Information and Tourism International Society for Optical Engineering (SPIE) Ministry of Science and Technology (MoST) Molecular Imaging Center, National Taiwan University Research Center for Applied Sciences, Academia Sinica Taiwan Information Storage Association (TISA) Taiwan Photonics Society (TPS) The Optical Society (OSA)
Welcome message
On behalf of the ICNP 2016 Organizing Committee, we are honored and delighted to welcome you all to the 9th International Conference on Nanophotonics (ICNP 2016), that will take place from March 21 to 25, 2016 at Academia Sinica, Taipei, Taiwan. This conference is a unique event where the latest advances in optics and photonics both in nano- and micro-scale will be reported and discussed.
The technical program is enriched by the 9 plenary talks, 41 invited talks, 2 short courses, and around 170 technical papers split between 3 parallel oral sessions and the poster session. The comprehensive coverage of conference themes includes microscopy and nanoscopy, silicon photonics, quantum optics, metamaterials, plasmonics, transformation optics, materials for micro- and nano-photonics, nanofabrication, and photonic devices. We sincerely expect to provide a forum for researchers and scientists to report their works and exchange information with fellow co-workers.
The success of the conference depends largely on many people who have worked with us in planning and organizing this event. We greatly appreciate their tremendous efforts and continuing supports. We would like to thank you for your participation in the conference as well. Your participation is what makes ICNP 2016 a success. We hope you will find the conference and your stay in Taiwan both valuable and enjoyable.
Sincerely,
Din Ping Tsai Ta-Jen Yen Conference Chairs Committees Conference Chair and Conference Co-Chair Din Ping Tsai (RCAS, Academia Sinica, Taiwan) Ta-Jen Yen (National Tsing Hua University, Taiwan) Organizing Committee Chairs Yun-Chorng Chang (RCAS, Academia Sinica, Taiwan) Min-Hsiung Shih (RCAS, Academia Sinica, Taiwan)
Organizing Committee Members Bi-Chang Chen (RCAS, Academia Sinica, Taiwan) Kuo-Ping Chen (National Chiao Tung University, Taiwan) Hai-Pang Chiang (National Taiwan Ocean University, Taiwan) Shih-Kang Fan (National Taiwan University, Taiwan) Chen-Bin Huang (National Tsing Hua University, Taiwan) Jer-Shing Huang (National Tsing Hua University, Taiwan) Yung-Chiang Lan (National Cheng Kung University, Taiwan) Jiunn-Woei Liaw (Chang Gung University, Taiwan) Shien-Kuei Liaw (National Taiwan University of Science and Technology, Taiwan) Tien-Chang Lu (National Chiao Tung University, Taiwan) Yuan Luo (National Taiwan University, Taiwan) Chih-Ming Wang (National Dong Hwa University, Taiwan)
Technical Program Committee Chair Pei-Kuen Wei (RCAS, Academia Sinica, Taiwan) Technical Program Committee Members Javier García de Abajo (Instituto de Óptica–CSIC, Spain) C. T. Chan (Hong Kong University of Science and Technology, HK) Bi-Chang Chen (RCAS, Academia Sinica, Taiwan) Yiping Cui (Southeast University, China) Nicholas X. Fang (MIT, USA) Michael A. Fiddy (UNC Charlotte, USA) Harald Giessen (University of Stuttgart, Germany) Qihuang Gong (Peking University, China) Min Gu (Swinburne University of Technology, Australia) Minghui Hong (National University of Singapore, Singapore) Der-Ray Huang (National Dong Hwa University, Taiwan) Chennupati Jagadish (Australian National University, Australia) Zhiyuan Li (Institute of Physics, CAS, China) Ai Qun Liu (Nanyang Technological University) Xiangang Luo (Institute of Optics and Electronics, CAS, China) Junle Qu (Shenzhen University, China) Jung-Tsung Shen (Washington University in St. Louis, USA) Greg Sun (University of Massachusetts Boston, USA) Takuo Tanaka (RIKEN, Japan) Limin Tong (Zhejiang University, China) Jiangeng Xue (University of Florida, USA) Qiwen Zhan (University of Dayton, USA) Lei Zhou (Fudan University, China)
5 3F 4F SPECIAL PROGRAM
I. EXHIBITION Exhibition will be available during ICNP 2016. Date & Time: 14:00-19:00 Monday, March 21 09:00-17:30 Tuesday, March 22 09:00-20:00 Wednesday, March 23 09:00-14:00 Thursday, March 24 09:00-16:00 Friday, March 25
Place: 4F, Humanities and Social Sciences Building (HSSB), Academia Sinica 128 Academia Road, Section 2, Nangang, Taipei 115, Taiwan
II. SOCIAL PROGRAM Welcome Reception Date & Time: 17:00-19:00 Monday, March 21 Place: 4F, Recreation Hall, Humanities and Social Sciences Building (HSSB), Academia Sinica (128 Academia Road, Section 2, Nangang, Taipei 115, Taiwan) Fee: Included in conference fee. Traffic: N/A Banquet Date & Time: 18:30-20:30 Tuesday, March 22 Place: B1, Chang Yung-Fa Foundation (11 Zhongshan S. Rd., Zhongzheng Dist., Taipei 100, Taiwan) Map & Transportation Fee: : Included in conference fee. Registered accompanying person are invited to the banquet. Traffic: The shuttle bus will be at the 1st floor of the conference building at 17:30 PM Dinner Date & Time: 17:10-18:00 Wednesday, March 23 Place: 4F, Recreation Hall, Humanities and Social Sciences Building (HSSB), Academia Sinica (128 Academia Road, Section 2, Nangang, Taipei 115, Taiwan) Fee: Included in conference fee. Traffic: N/A Poster Sessions Date & Time: 18:00-20:00 Wednesday, March 23 Place: 4F, Humanities and Social Sciences Building (HSSB), Academia Sinica (128 Academia Road, Section 2, Nangang, Taipei 115, Taiwan) Fee: Included in conference fee. Traffic: N/A
III. TOUR Date & Time: 13:30-17:30 Thursday, March 24, Place: National Palace Museum Taipei 101 Fee: : Included in conference fee. Registered accompanying person are invited to the tour. Traffic: The shuttle bus will be at the 1st floor of the conference building at 13:30 PM and depart at 13:40 PM. The tour will end at around 17:30. Please note that the shuttle bus for returning after the city tour is not provided.
ICNP 2016 Secretariat OPPORTUNITY TO PUBLISH IN SPECIAL ISSUE OF OPTICS EXPRESS
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We are pleased to announce that Optics Express will publish a selection of papers from the International Conference on Nanophotonics (ICNP 2016). This conference aims to explore novel ideas in nanophotonic science and technology that might enable technological breakthroughs in high impact areas such as, but not limited to: Microscopy and Nanoscopy, Nano-optoelectronics, Metamaterials and Plasmonics, Nanofabrication, Photonic Crystals and Nanofibers, Nanocharacterization, Photonic Crystals and Lasers, Green Photonics and Photovoltaic, Self- Assembly and Nanochemistry, Nanolasers, Nanodevices and Integration, Nanobiophotonics, Quantum Optics and Computing, Silicon Photonics, and Nonlinear Optics. The guest editors will select the best papers from the conference.
All papers must present original, previously unpublished work, and will be subject to the normal standards and peer-review process of the journal. To be eligible for publication, the papers need to add substantial and/or significant new information to the original conference summary. Appropriate attribution to the conference paper must also be given in the manuscript. Normal Optics Express Article Processing Charges will apply to all published articles.
Manuscripts must be prepared according to the standard author instructions for submission to Optics Express and submit through OSA's online submission system. When submitting, authors must specify that the manuscript is for the Nanophotonics feature issue (choose from the drop- down menu).
FEATURE ISSUE EDITORS (IN ALPHABETICAL ORDER) Jiunn-Woei Liaw, Chang Gung University, Taiwan Greg Sun, University of Massachusetts Boston, USA Din Ping Tsai, RCAS, Academia Sinica, Taiwan Ta-Jen Yen, National Tsing Hua University, Taiwan
FEATURE ANNOUNCEMENT ON THE OPTICS EXPRESS JOURNAL PAGE: https://www.osapublishing.org/oe/journal/oe/feature_announce/np2016.cfm Table of contents
1 Program i
2 Sessions
March 21, 2016 (Monday) 14:05-15:05 MON-SC01 2 15:35-16:35 MON-SC02 6
March 22, 2016 (Tuesday) 08:30-09:30 TUE-PL01 10 10:00-12:00 TUE-PL02 14 13:30-15:00 TUE-PL03 22 15:30-17:30 TUE-PL04 28
March 23, 2016 (Wednesday) 08:15-09:00 WED-PL01 36 09:10-10:10 WED-IC-S1 40 WED-R1-S1 46 WED-R2-S1 52 10:30-12:00 WED-IC-S2 58 WED-R1-S2 64 WED-R2-S2 70 13:30-15:00 WED-IC-S3 76 WED-R1-S3 82 WED-R2-S3 88 15:30-17:10 WED-IC-S4 94 WED-R1-S4 102 WED-R2-S4 110 18:00-20:00 Poster Session 222 March 24 (Thursday) 08:15-09:00 THU-PL1 118 09:10-10:10 THU-IC-S1 122 THU-R1-S1 128 THU-R2-S1 134 10:30-12:00 THU-IC-S2 140 THU-R1-S2 146 THU-R2-S2 152
March 25, 2016 (Friday) 08:30-10:10 FRI-IC-S1 158 FRI-R1-S1 166 FRI-R2-S1 174 10:30-12:10 FRI-IC-S2 182 FRI-R1-S2 190 FRI-R2-S2 198 13:30-15:10 FRI-IC-S3 204 FRI-RI-S3 210 FRI-R2-S3 216
3 Author Index 329 The 9th International Conference on Nanophotonics (ICNP 2016)
Time Monday, March 21, 2016 13:30R16:30 Registration Room: 2nd Conference Room (3F) 14:00R14:05 Session: MON SC01 Chair: Vasily Klimov SC 1 Joseph W. Haus 14:05R15:05 University of Dayton, USA Essential Concepts in Nanophotonics 15:05R15:35 Coffee Break Session: MON SC02 Chair: Kosei Ueno SC 2 Paras N. Prasad 15:35R16:35 State University of New York at Buffalo, USA Bionanophotonics 17:00R19:00 Welcome reception
i Date Tuesday, March 22, 2016 Room: International Conference Hall (4F) Opening Remarks: Director Din Ping Tsai 08:00‐08:30 Session: TUE‐PL01 Chair: Ta‐Jen Yen PL‐1 Eric Betzig 08:30‐09:30 Janelia Research Campus, Howard Hughes Medical Institute, USA Imaging Life at High Spatiotemporal Resolution 09:30‐10:00 Group Photo & Coffee Break Session: TUE‐PL02 Chair: Vladimir Shalaev, Min‐Hsiung Shih PL‐2 Naomi Halas 10:00‐10:45 Rice University, USA Sustainable Plasmonics and Plasmonics for Sustainability PL‐3 Xiang Zhang 10:45‐11:30 Univ. of California at Berkeley, USA Parity‐time Symmetry Photonics IN‐1 Na Ji 11:30‐12:00 Janelia Research Campus, Howard Hughes Medical Institute, USA From star to neuron – adaptive optical microscopy for deep brain imaging 12:00‐13:30 Lunch Session: TUE‐PL03 Chair: Aleksandra B. Djurišić, Yoshimasa Kawata PL‐4 Chennupati Jagadish 13:30‐14:15 Australian National University, Australia Semiconductor Nanowires for Optoelectronics and Energy Applications PL‐5 Vladimir Shalaev 14:15‐15:00 Purdue University, USA New Materials Platforms for Nanophotonics 15:00‐15:30 Coffee Break Session: TUE‐PL04 Chair: L. (Kobus) Kuipers, Pei‐Kuen Wei PL‐6 Nikolay Zheludev 15:30‐16:15 University of Southampton, UK & Nanyang Technological University, Singapore Metamaterials: Optical Properties on Demand PL‐7 Harald Giessen 16:15‐17:00 Univ. of Stuttgart, Germany Short‐range surface plasmonics and its (sub‐)femtosecond dynamics IN‐2 Aleksandra B. Djurišić 17:00‐17:30 The University of Hong Kong, Hong Kong Perovskite solar cells – optimizing the perovskite and device fabrication 18:30‐20:30 Banquet
2 ii
Date Wednesday, March 23, 2016 Room: International Conference Hall (4F)
Session: WED PL01 Chair: Cheng Wei Qiu PL 8 Satoshi Kawata 08:15 – 09:00 Osaka University, Japan Optical 3D nanoRfabrication: drawing or growing? 09:00 – 09:10 Break International Conference Hall (4F) 1st Conference Room (3F) 2nd Conference Room (3F) Session: WED IC S1 Session: WED R1 S1 Session: WED R2 S1 Chair: Uriel Levy, Chair: Fan Wang, Chair: Ann Roberts, Chen Bin Huang Hai Pang Chiang Shien Kuei Liaw IN 3 Anatoly Zayats IN 4 Prabhat Verma IN 5 Ai Qun Liu King's College London, UK Osaka University, Japan Nanyang Technological University, 09:10R09:40 Nonlinear Processes in HighRResolution Nanoimaging Singapore Plasmonic Metamaterials with TipREnhanced Raman MetaRfluidic Metasurface Spectroscopy IN 6 Gary P. Wiederrecht IN 7 Kosei Ueno IN 8 Eric Plum Argonne National Laboratory, USA Hokkaido University, Japan University of Southampton, UK Nanophotonic Materials for PlasmonRenhanced Reconfigurable Nanomembrane 09:40R10:10 Enhanced Ultrafast Optical photochemistry using Metadevices Response and Efficient Energy nanoRengineered Propagation gold particles 10:10R10:30 Coffee Break Session: WED IC S2 Session: WED R1 S2 Session: WED R2 S2 Chair: Gary P. Wiederrecht, Chair: Mikhail Noginov, Chair: Eric Plum, Wing Yim Tam Ewa Kowalska Hung chun Chang IN 9 Uriel Levy IN 10 Fan Wang IN 11 Ann Roberts The Hebrew University of Macquarie University, Australia University of Melbourne, Australia Jerusalem, Israel Advanced Optical Microscopy Metasurfaces as spatial filters for 10:30R11:00 LightRmatter interactions in enabled single nanoparticle optical information processing nanophotonics systems characterization and its applications Oral 1 Kuang Yu Yang Oral 2 Pin Yi Li Oral 3 Xin Tao He EPFL, Switzerland NTU, Taiwan Sun Yat Sen University , China 11:00R11:20 Second Harmonic Generation in Superresolution using Dielectric SiliconRBased Metalens with Zero Reflective Gradient Microspheres Refractive Index Metasurfaces Oral 4 You Xin Huang Oral 5 Hsi Hsun Chen Oral 6 Meng Chi Chen NTHU, Taiwan NTU, Taiwan NTHU, Taiwan MillimeterRsized ultraRsmooth 3D highRresolution structured Sorting SelfRAssembled 11:20R11:40 singleRcrystalline gold flakes for illumination microscopy based on SingleRCrystalline Gold Microplates largeRarea plasmonic and Bayesian estimation by Eddy Current metasurfaces applications Oral 7 Ruei Han Jiang Oral 8 Chen Yen Lin Oral 9 Shaojie Ma NTHU, Taiwan NTU, Taiwan Fudan University, China 11:40R12:00 Practical and High Efficient NonRscanning InRvivo Tailor the functionalities of Radial Coupling Plasmonic Probe threeRdimensional structured metasurfaces based on a complete Design for Near Field Application illumination microscopy phase diagram 12:00R13:30 Lunch Break
iii Date Wednesday, March 23, 2016 Session: WED IC S3 Session: WED R1 S3 Session: WED R2 S3 Chair: Anatoly Zayats, Chair: Prabhat Verma, Chair: Ai Qun Liu, Kuo Ping Chen Tien Chang Lu Yung Chiang Lan IN 12 Olivier J. F. Martin IN 13 Vasily Klimov IN 14 Takuo Tanaka Swiss Federal Institute of P.N. Lebedev Physical Institute, Russia RIKEN, Japan Technology Lausanne, Switzerland New Optical Properties of Metamaterial absorber for 13:30R14:00 Using the modal structure of Perforated Metal Films and Their attomole level molecular plasmonic systems to boost Applications detection their efficiency in the linear and nonRlinear regimes Oral 10 Wing Cheung Law Oral 11 Iyan Subiyanto Oral 12 Ho Ming Dick Leung PolyU, Hong Kong Chang Gung Univ., Taiwan HKUST, Hong Kong 14:00R14:20 ManganeseRdoped NearRinfrared Luminance Enhancement by the Giant Plasmonic Circular Dichroism Emitting Nanocrystals for in vivo Incorporation of Au Nanoparticles in Ag Staircase Nanostructures Biomedical Imaging in Polymer LightREmitting Diodes Oral 13 Jhen Hong Yang Oral 14 Pei Yu Chuan Oral 15 Kel Meng See NCTU, Taiwan NDHU, Taiwan NTHU, Taiwan 14:20R14:40 Evanescent fields Assisted in Innovative Low Intensity Light Unidirectional Beaming of SymmetryRBreaking of Gold Simulators for Evaluating DSSCs Photoluminescence from Gold Nanoantenans YagiRUda Nanoantenna Oral 16 Shiho Ikegami Oral 17 Trong Huynh Buu Ngo Oral 18 Chen Yan Okayama University, Japan Academia Sinica, Taiwan EPFL, Switzerland 14:40R15:00 SelfRassembly with Size dependent evolution of the Narrowband metasurfaces based LangmuirRBlodgett method for resonant mode in porous ZnO on Fano resonances gold nanodimer structures spherical microcavity 15:00R15:30 Coffee Break Session: WED IC S4 Session: WED R1 S4 Session: WED R2 S4 Chair: Olivier J. F. Martin, Chair: Vasily Klimov, Chair: Takuo Tanaka, Greg Sun Shing Hoa Wang Shiuan Yeh Chen IN 15 L. (Kobus) Kuipers IN 16 Mikhail Noginov IN 17 Cheng Wei Qiu FOM institute AMOLF, Netherlands Norfolk State University, USA National University of Nanoscale vector fields LightRMatter Interactions in Weak Singapore, Singapore 15:30R16:00 Rvisualization, fascination and Strong Coupling Regimes NanoRmanipulation of SpinR and applicationR Orbital Angular Momentum via VisibleRfrequency Metasurfaces IN 18 Joseph W. Haus IN 19 Ewa Kowalska IN 20 Seung Han Park University of Dayton, USA Hokkaido University, Japan Yonsei University, Korea ThirdRHarmonic Generation in Plasmonic photocatalysts for Multimodal Nonlinear Optical 16:00R16:30 Titania/Silver Photonic Crystals environmental applications Microscopy for InRvivo and LabelRfree Biological Imaging Oral 19 Shih Kang Fan Oral 20 Emiliano Cortes Oral 21 Shean Jen Chen NTU, Taiwan Imperial College London, UK NCKU, Taiwan 16:30R16:50 Multiphase Optofluidics on an Tailoring lightRmatter interaction Adaptive Optics Temporal Electromicrofluidic Platform in plasmonic nanoantennas FocusingRbased Multiphoton Excitation Microscopy Oral 22 Chih Ming Wang Oral 23 Tien Chang Lu Oral 24 Qiang Wang NDHU, Taiwan NCTU, Taiwan Nanjing Univeristy, China CostReffective and AgR and AlRbased surface plasmon Measuring the Topological Phase 16:50R17:10 visibleRlightRdriven photocatalyst polariton nanolasers Through the Interface States for green applications Between Metasurfaces and Photonic Crystals 17:10R18:00 Dinner Buffet
18:00R20:00 Poster Session Chair: YungRChiang Lan,ġTienRChang Lu
iv Date Thursday, March 24, 2016 Room: International Conference Hall (4F) Session: THU PL1 Chair: Chi Kuang Sun PL 9 Lihong Wang Washington University in St. Louis, USA 08:15 – 09:00 Redefining the Spatiotemporal Limits of Optical Imaging: Photoacoustic Tomography, Wavefront Engineering, and Compressed Ultrafast Photography 09:00 – 09:10 Break International Conference Hall (4F) 1st Conference Room (3F) 2nd Conference Room (3F) Session: THU IC S1 Session: THU R1 S1 Session: THU R2 S1 Chair: Kotaro Kajikawa, Chair: Ken Tye Yong, Chair: Chih Ming Wang Yuan Luo Jer Shing Huang Chu Hsuan Lin IN 21 Na Liu IN 22 Paolo Biagioni IN 23 Junichi Takahara University of Heidelberg, Germany Politecnico di Milano, Italy Osaka University, Japan 09:10R09:40 Plasmonic walkers on DNA Germanium midRinfrared MetalRAirRMetal Nanocavity in a Origami plasmonics for sensing Slanted Plasmonic Nanowire Suspended on a Metal Substrate IN 24 Minghui Hong IN 25 Jeongyong Kim IN 26 Feng Qiu National University of Singapore, Sungkyunkwan University, South Kyushu University, Japan Singapore Korea Hybrid ElectroRoptic Polymer 09:40R10:10 SubRdiffraction Limit Imaging by Optical Visualization of Exciton Modulators Supercritical Lens with Competitions in TMD UltraRlong Working Distance Monolayers 10:10R10:30 Coffee Break Session: THU IC S2 Session: THU R1 S2 Session: THU R2 S2 Chair: Na Liu, Chair: Paolo Biagioni, Chair: Junichi Takahara, Shih Kang Fan Chih Wei Chu Chi Chen IN 27 Yoshimasa Kawata IN 28 Ken Tye Yong IN 29 Jian Wen Dong Shizuoka University, Japan Nanyang Technological University, Sun Yat Sen University, China 10:30R11:00 NanoRimaging of live cells with Singapore Molding the spin flow in valley electron beam excitation Plasmonic Gold Nanorods for photonic crystals assisted microscope Biophotonics Oral 25 Chia Yuan Chang Oral 26 Jacky FC Loo Oral 27 Shiuan Yeh Chen NCKU, Taiwan CUHK, Hong Kong NCKU, Taiwan Fast volumetric imaging and A nonRPCR Surface Plasmon Plasmonic coreRsatellite 11:00R11:20 patterned illumination via Resonance Platform with assemblies with high yield and DMDRbased temporal focusing AptamerRbased BioRbarcode stability multiphoton microscopy assay for antiRcancer drug screening application Oral 28 Yu Hsun Chou Oral 29 Sung Gyu Park Oral 30 Genny Anne Pang NCTU, Taiwan KIMS, Korea TUM, Germany Lasing characteristic of ZnO Holographic Fabrication of Highly Experimental Determination of 11:20R11:40 plasmonic laser with various gap Sensitive and Uniform Plasmonic Absorption, Scattering, and layer thickness Sensing Platform Photoacoustic Signal from Gold Nanoparticles Oral 31 Chiao Yun Chang Oral 32 Chen Bin Huang Oral 33 Kotaro Kajikawa Academia Sinica, Taiwan NTHU, Taiwan Tokyo Tech, Japan Optimized enhancement Metasurface for creating orbital BioRmetamaterial: Black Ultrathin 11:40R12:00 photoluminescence of monolayer angular momenta and Gold Film Fabricated on Lotus Leaf MoS2 by covering the densities of microparticle manipulations plasmonic Au nanonrods 12:00R13:30 Lunch Break 13:30 City Tour v Date Friday, March 25, 2016 International Conference Hall (4F) 1st Conference Room (3F) 2nd Conference Room (3F) Session: FRI IC S1 Session: FRI R1 S1 Session: FRI R2 S1 Chair: Mu Wang, Chair: Hui Liu, Chair: Masanobu Haraguchi, Chao Cheng Kaun Shihhui Gilbert Chang Ya Yan Lu IN 30 Qihuang Gong IN 31 Wolfgang Fritzsche IN 32 Manfred Eich Peking University, China Leibniz Institute of Photonic Hamburg University of Technology, 08:30R09:00 Manipulating Light with Nano Technology, Germany Germany Photonic Structures Bioanalytics using single Tailored thermal emission from plasmonic nanostructures refractory metamaterials IN 33 Zouheir Sekkat IN 34 Liwei Liu IN 35 Lei Zhou Moroccan Foundation for Advanced Changchun University of Science Fudan University, China Science, Morocco and Technology, China 09:00R09:30 Metasurfaces for highRefficiency Towards UltraRhigh Sensitivities HeavyRmetal free QDs surface plasmon coupler and in Plasmon Based Optical preparation and biomedical active dispersion compensation Sensors application Oral 34 Kuang Li Lee Oral 35 Yung Chiang Lan Oral 36 Kuo Ping Chen Academia Sinica, Taiwan NCKU, Taiwan NCTU, Taiwan Enhancing Surface Sensitivity of Tunable tapered waveguide for Fabrication of Titanium Nitride as 09:30R09:50 Metallic Nanostructures Using efficient compression of light to Plasmonic Materials with Room ObliqueRAngle Induced Fano graphene plasmons Temperature HighRpower Impulse Resonances Magnetron Sputtering Oral 37 Yu Ju Hung Oral 38 Min Hsiung Shih Oral 39 Bi Chang Chen NSYSU, Taiwan Academia Sinica, Taiwan Academia Sinica, Taiwan Comprehensive High Circular Dichroism Lattice Light Sheet Microscopy: 09:50R10:10 ThreeRDimensional Analysis of Ultraviolet Lasing from Planar From Molecules to Organism Surface Plasmon Polariton Spiral MetalRGalliumRNitride Imaging Modes at Uniaxial Liquid Nanowire Cavity CrystalRMetal Interface 10:10R10:30 Coffee Break Session: FRI IC S2 Session: FRI R1 S2 Session: FRI R2 S2 Chair: Liwei Liu, Chair: Wolfgang Fritzsche, Chair: Lei Zhou, Shu Wei Chang Yun Chorng Chang Yi Jun Jen IN 36 Mu Wang IN 37 Hui Liu IN 38 Masanobu Haraguchi Nanjing University, China Nanjing University, China Tokushima University, Japan An Approach to Tune the Mimicking Einstein’s Ring in Polymer core channel plasmonic 10:30R11:00 Polarization State of Light with Curved Waveguides waveguide for SiRPlasmon hybrid Metastructures over a Broad photonic integrated circuit Frequency Range IN 39 Jr Hau He IN 40 Greg Sun IN 41 Tao Li King Abdullah Univ. of Science & UMass Boston, USA Nanjing Unviersity, China Technology, Saudi Arabia Ge/Ge0.975Sn0.025/Ge pRiRn InRplane Holography for Indefinite 11:00R11:30 Photon managements by Photodetector Operated with Plasmonic Beam Engineering employing nanostructures for BackRside Illumination optoelectronic devices Oral 40 Tsung Sheng Kao Oral 41 Victor Yang Oral 42 Zhong Fan NCTU, Taiwan Ryerson University, Canada Nanjing University, China Enhanced Coherent Light Pulsed and CW adjustable Flexible coherent control of 11:30R11:50 Emission Properties in 1942nm singleRmode allRfiber plasmonic spinRHall effect SolutionRprocessed Lead Halide TmRdoped fiber laser system for Perovskites surgical laser soft tissue ablation applications
vi 6 Date Friday, March 25, 2016 Oral 43 Yu bin Chen Oral 44 Ching Hang Chien Oral 45 Wen Sheng Gao NCKU, Taiwan Academia Sinica, Taiwan HKUST, Hong Kong Tailoring Optical Responses of LineRshapes of WGM enhanced Determination of Zak phase by 11:50R12:10 Glass Using Silver NanoRPillars for photoluminescence spectra of reflection phase in 1D photonic Saving Energy ZnO microspheres with crystals excitonRpolariton effect 12:10R13:30 Lunch Break Session: FRI IC S3 Session: FRI RI S3 Session: FRI R2 S3 Chair: Zouheir Sekkat, Chair: Manfred Eich, Chair: Seung Han Park Yu Bin Chen Tsung Sheng Kao Yuh Jen Cheng Oral 46 Yi Chieh Lai Oral 47 Cheng Wei Chang Oral 48 Fan Cheng Lin NCKU, Taiwan NTHU, Taiwan NTHU, Taiwan Plasmonic Archimedean Spiral Surface Plasmon Polaritons Novel Design of Plasmonic 13:30R13:50 Modes on Concentric Metal Ring Amplitude Modulations by using Doppler Grating for Color Sorting Gratings Zeeman effect and Polarization and Index Sensing control Oral 49 Ya Tang Yang Oral 50 Tian Yang Oral 51 Po Hao Wang NTHU, Taiwan Shanghai Jiao Tong Univ, China NTU, Taiwan Freezing photothermal Phonon Stimulated Scattering and TransformationRoptics 13:50R14:10 convection in plasmonic optical Single Molecule Dynamics in macroscopic visibleRlight beyond lattice Reproducible Ultrasensitive SERS two dimensions cloaking Hotspots Oral 52 Yihsin Chien Oral 53 Agnes Purwidyantri Oral 54 Shang Yung Yu Academia Sinica, Taiwan Chang Gung University, Taiwan Chang Gung University, Taiwan Angled NanosphericalRLens NonRlithographic Nanopatterning Photoacoustic Signal of CoreRshell 14:10R14:30 Lithography as a highRthroughput for SERS AuRnanoarray Gold Nanorod Colloid method to fabricate periodic arrays of various nanostructures Oral 55 Ieng Wai Un Oral 56 Ya Yan Lu Oral 57 Anna Reszka NTHU, Taiwan CityU, Hong Kong PAS, Poland 14:30R14:50 Interface States of Binary Improved bull’s eye structures for Local optical and structural Hyperbolic Metamaterials higher transmission properties of GaN nanowires with AlxGa1RxN segments Oral 58 Husneni Mukhtar Oral 59 R. Vijaya Oral 60 Agnieszka Pieniazek ICube, France IIT Kanpur, India PAS, Poland Performance comparison of air Broadband negative refraction in Cathodoluminescence studies of 14:50R15:10 and immersion Linnik objectives a twoRdimensional photonic ZnO microrods grown by in coherence scanning crystal without any negative index hydrothermal method interferometry material 15:10R15:20 Break 15:20R15:40 Closing Ceremony/Award
vii 7 MON-SC01
Session: MON-SC01
Date: March 21 (Monday) Time: 14:05-15:05 Session Chair: Vasily Klimov (Russian Academy of Sciences, Russia) Room: 2nd Conference Room (3F) Short Course
Prof. Joseph W. Haus
University of Dayton, USA
March 21, 2016 Essential Concepts in Nanophotonics 14:05-15:05 2nd Conference Room (3F)
Biography for Joseph W. Haus
Joseph W Haus is a professor of Electro-Optics, Electrical and Computer Engineering and Physics at the University of Dayton. His professional journey included several positions including: a NRC post-doctoral fellow at the National Bureau of Standards; a visiting scientist at the Kernforschungsanlage in Jülich Germany; an assistant at the Universität Essen GHS, and a sabbatical year at the University of Tokyo. He was a physics faculty member at Rensselaer Polytechnic Institute for 15 years rising to the rank of professor. In 1999 he was appointed Director of the Electro-Optics Program at the University of Dayton and served for 13 years in that position. Haus is a fellow of the APS, SPIE and OSA. His research interests include nonlinear and quantum phenomena in nanostructured materials and fiber lasers and sensors. He has around 200 journal publications. He is a founding chair of the International Conference on Nanophotonics. He serves as an associate editor on two journals, including the Associate Editor in Chief of Chinese Optics Letters.
2 SC-1
3
MON-SC02
Session: MON-SC02
Date: March 21 (Monday) Time: 15:35-16:35 Session Chair: Kosei Ueno (Hokkaido University, Japan) Room: 2nd Conference Room (3F) Short Course
Prof. Paras Prasad
State University of New York at Buffalo, USA
March 21, 2016 Bionanophotonics 15:35-16:35 2nd Conference Room (3F)
Biography for Paras Prasad
PARAS N PRASAD, Ph.D. is the SUNY Distinguished Professor of Chemistry, Physics, Electrical Engineering and Medicine; the Samuel P. Capen Chair of Chemistry; and the Executive Director of the Institute for Lasers, Photonics and Biophotonics at the University at Buffalo. He was named among the top 50 sciences and technology leaders in the world by Scientific American in 2005. He has published over 740 papers in high-impact journals; four monographs practically defining the fields of organic nonlinear optics, Biophotonics, Nanophotonics, Nanobioengineering and Nanomedicine; eight edited books; and holds numerous patents. He is the recipient of Morley Medal; Schoellkopf Medal; Guggenheim Fellowship, Sloan Fellowship; Western New York Health Care Industries Technology/Discovery Award; Excellence in Pursuit of Knowledge Award of the SUNY Research Foundation; Fellow of the APS, OSA, and SPIE. He is on the 2014 Thompson Reuters “Highly Cited Researchers” list . He received Honorary Doctorate from KTH (2013), Stockholm, Sweden ; and Honoris Causa Doctor from the Aix-Marseille University (AMU), Marseille, France (2014). Prasad received in 2015 the University at Buffalo inaugural Innovation Award for his most successful invention that formed the basis for the publically trading company, Nanobiotix based in Paris, valued for over 300 million dollars.
6 SC-2
Bionanophotonics taps on nanoscale manipulation of optical interactions, control of light propagation and energy flow on nanoscale to produce a major advancement in biotechnology and nanomedicine.1-3. It utilizes Nanophotonics to diagnose a disease at the early stage as well as to guide targeting, activate multiple . A major limitation of bionanophotonics is the issue of light penetration in tissues. This course will discuss near IR emitters and in-situ photon upconversion nanocrystals for optical imaging and activation of therapies. Examples of near IR emitters presented are silicon quantum dots and Copper sulfide based quantum dots. Examples of up-conversion materials are nonlinear nanocrystals such as ZnO which can use four wave mixing , sum frequency generation as well as second harmonic generation to convert a deep tissue penetrating Near IR light at the targeted biological site to a desired shorter wavelength light suitable for bio imaging or activation of a therapy. Another type of upconversion materials is rare-earth ion doped optical nanotransformers. They in a in a core-multiple shell design to minimize cross-relaxation and surface quenching ,transform a Near IR (NIR) light from an external source by a sequential single photon absorption , in situ and on demand, to a wavelength needed for deep tissue imaging as well as for a specific diagnostic or therapeutic application. The control of excitation dynamics using nanophotonics interactions to achieve maximum selective upconversion by these two types of processes will be presented. The relative merits of these two types of upconversion materials will be discussed. Using these nanoparticles as imaging probes, we have also demonstrated NIR high contrast 3D imaging in vivo. They can be used for studying biodistribution to ascertain targeting, and eventually follow clearance of a nanoparticle delivery system. The use of Nanophotonics for photoacoustic imaging will also be described .The application of in-situ photon upconversion for photodynamic therapy, drug release and gene therapy will also be covered. We have also demonstrated remote and noninvasive actuation of optogenetics using near IR absorbing optical nanotransformers that can provide an effective intervention /augmentation strategy to enhance the cognitive state and lead to a foundation for futuristic vision of super human capabilities. This exciting direction will be introduced. This talk will conclude with a discussion of new opportunities.
[1] . [2] . [3] .
7
TUE-PL01
Session: TUE-PL01
Date: March 22 (Tuesday) Time: 08:30-09:30 Session Chair: ? R] ` ? 0 7 ? 1 Room: Plenary Session
Dr. Eric Betzig
2014 Nobel Laureate Howard Hughes Medical Institute, USA
March 22, 2016 Imaging Life at High Spatiotemporal Resolution 08:30-09:30 International Conference Hall (4F)
Biography for Eric Betzig
Eric Betzig is a Group Leader at the Janelia Research Campus in Ashburn, VA. His thesis at Cornell University (Ph.D. ’88) and subsequent work as a PI at AT&T Bell Labs involved the development of near-field optics – an early form of super-resolution microscopy. Tiring of academia, he resigned, and in 1995 published the concept that would become localization microscopy while unemployed. He eventually served as VP of R&D at Ann Arbor Machine Tool Company, but resigned in 2002 when the technologies he developed there failed commercially. In 2005, he and his fellow Bell Labs expatriate, Harald Hess, used photoactivated fluorescent proteins to bring super-resolution localization microscopy to reality, building the first prototype in the living room of Dr. Hess. For this work, he is a co-recipient of the 2014 Nobel Prize in Chemistry. Today, he continues to work in super-resolution, as well as with non-diffracting light sheets for the 4D dynamic imaging of living systems and adaptive optics to recover optimal imaging performance deep within aberrating tissues.
10 PL-1
Imaging Life at High Spatiotemporal Resolution
Eric Betzig Janelia Research Campus, HHMI [email protected]
As our understanding of biological systems as increased, so has the complexity of our questions and the need for more advanced optical tools to answer them. For example, there is a hundred-fold gap between the resolution of conventional optical microscopy and the scale at which molecules self-assemble to form sub-cellular structures. Furthermore, as we attempt to peer more closely at the dynamic complexity of living systems, the actinic glare of our \ " of living tissue can seriously impede our ability to image at high resolution, due to the resulting warping and scattering of light rays. I will describe three areas focused on addressing these # [ at the nanoscale [1]; plane illumination microscopy using non-diffracting beams for noninvasive imaging of three-dimensional dynamics within live cells and embryos [2]; and adaptive optics to recover optimal images from within optically heterogeneous specimens [3].
[1] D. Li. et al., Science 349, aab3500 (2015). [2] B.-C. Chen, et al., Science 346, 1257998 (2014). [3] K. Wang, et al., Nat. Methods 11, 625-628 (2014).
11
TUE-PL02
Session: TUE-PL02
Date: March 22 (Tuesday) Time: 10:00-12:00 Session Chair: Vladimir Shalaev (Purdue University, USA) = R . . % % ? 1 Room: Plenary Session
Prof. Naomi Halas
Stanley C. Moore Professor Rice University, USA
Sustainable Plasmonics and Plasmonics for March 22, 2016 10:00-10:45 Sustainability International Conference Hall (4F)
Biography for Naomi Halas
Naomi Halas is the Stanley C. Moore Professor in Electrical and Computer Engineering, Professor of Chemistry, Professor of Physics and Astronomy, Professor of Bioengineering, founding director of the Laboratory for Nanophotonics at Rice University, and founding Director of the Smalley- Curl Institute. She was a graduate research fellow at IBM Research, Yorktown, NY, served as a postdoctoral associate at AT&T Bell Laboratories and joined the Rice faculty in 1990. Halas is one of the pioneering researchers in the field of plasmonics, creating the concept of the “tunable plasmon” and inventing a family of nanoparticles with resonances spanning the visible and infrared regions of the spectrum. Halas pursues fundamental studies of coupled plasmonic systems as well as applications of plasmonics in biomedicine, optoelectronics, chemical sensing, photocatalysis, and solar energy, with a novel ‘solar steam’ technology. She is a recipient of the American Physical Society Frank Isakson Prize for Optical Effects in Solids and the R. W. Wood Prize of the Optical Society of America. She is a Fellow of six professional societies: OSA, APS, SPIE, IEEE, MRS, a member of the National Academy of Engineering, the National Academy of Sciences, the American Academy of Arts and Sciences, and the American Association for the Advancement of Science. She is a member of the Editorial Advisory Board of Chemical Physics Letters and Laser and Photonics Reviews, and an Associate Editor of Nano Letters.
14 PL-2
Sustainable Plasmonics and Plasmonics for Sustainability
N. J. Halas, Rice University
The intense research activity of the past two decades focused on the collective electronic oscillations in high-electron-density media, known as surface plasmons, has led to multiple % [ solar light harvesting, even nanomedicine. For many of these applications, the original focus on noble metals may ultimately limit their transition from the research laboratory to widely used commercial technologies. We will describe several research directions that, as they point towards more sustainable materials, open up new research opportunities. Aluminum, the most abundant metal on earth, opens the door to new colorimetric sensing applications and opportunities for active devices. Graphene in its smallest form, that of polycyclic aromatic hydrocarbon molecules, can support intense, optical frequency plasmon oscillations with the addition or removal of a single electron from the neutral molecule. In applications that directly address sustainability, we will discuss how plasmonic nanoparticles can be used for solar distillation of liquid mixtures, providing insight into the mechanism of nanoparticle-based distillation that in certain cases allows the distillation fraction to deviate dramatically from conventional thermal distillation processes.
15 Plenary Session
Prof. Xiang Zhang
Ernest S. Kuh Endowed Chaired Professor University of California, Berkeley, USA
March 22, 2016 Parity-time Symmetry Photonics 10:45-11:30 International Conference Hall (4F)
Biography for Xiang Zhang
Xiang Zhang is the inaugural Ernest S. Kuh Endowed Chaired Professor at UC Berkeley and Director of NSF Nano-scale Science and Engineering Center. He is the Director of the Materials Sciences Division at Lawrence Berkeley National Laboratory, and a member of the Kavli Energy Nano Science Institute.
16 PL-3
Parity-time Symmetry Photonics
Xiang Zhang University of California Berkeley, CA, USA E-mail address: [email protected]
Abstract: Judiciously designed balanced gain and loss structures, a hallmark of parity-time (PT) symmetric synthetic systems, are attractive due to their extraordinary dynamical properties. In this talk I will discuss the notion of PT symmetry in optical systems. Moreover, I will discuss [ lasing in PT symmetric periodically modulated ring lasers and simultaneous unidirectional lasing \ &
17 Invited talk
Dr. Na Ji
Howard Hughes Medical Institute, USA
From star to neuron – adaptive optical March 22, 2016 microscopy for deep brain imaging 11:30-12:00 International Conference Hall (4F)
Biography for Na Ji
Na Ji studied chemistry and physics as an undergraduate in University of Science and Technology of China and later a graduate student at University of California Berkeley. In 2006, she moved to Janelia Research Campus, Howard Hughes Medical Institute and worked with Eric Betzig on improving the speed and resolution of in vivo brain imaging. She started her own group in Janelia in 2011, where, in addition to imaging technology development, her lab apply the resulting techniques to outstanding problems in neurobiology.
18 IN-1
From star to neuron adaptive optical microscopy for deep brain imaging
Na Ji Janelia Research Campus, Howard Hughes Medical Institute, 19700 Helix Dr., Ashburn, VA 20147, United States E-mail address: [email protected]
Abstract: Imaging neurons deeply buried inside a live mouse using a microscope shares many similarities with gazing at distant stars with a telescope. In both cases, imaging capacity is limited by optical aberration and scattering. Wavefront shaping using adaptive optics has revolutionized astronomy by allowing us to obtain sharp images of celestial objects through the turbulent atmosphere [1]. Similar concepts may be applied to microscopy for optically transparent samples but not the scattering mammalian brains. In this talk, I will describe recent developments in adaptive optical microscopy [2-4], which allowed us to image both the input and output of mouse cerebral cortex with diffraction- limited resolution [5,6]. By making it possible to functionally image axons and neurons deep inside the mouse brain, these techniques enabled novel discoveries on the origin of orientation selectivity in mouse primary visual cortex.
Biosketch: Na Ji studied chemistry and physics as an undergraduate in University of Science and Technology of China and later a graduate student at University of California Berkeley. In 2006, she moved to Janelia Research Campus, Howard Hughes Medical Institute and worked with Eric Betzig on improving the speed and resolution of in vivo brain imaging. She started her own group in Janelia in 2011, where, in addition to imaging technology development, her lab apply the resulting techniques to outstanding problems in neurobiology.
[1] H. W. Babcock, Science 249, 253-257 (1990). [2] N. Ji, D. E. Milkie, E. Betzig, Nature Meth. 7, 141-147 (2010). [3] N. Ji, T. R. Sato, E. Betzig, Proc. Natl. Acad. Sci. U S A 109, 22-27 (2012). [4] D. E. Milkie, E. Betzig, N. Ji, Opt. Lett. 36, 4206-4208 (2012). [5] C. Wang, et al. Nature Meth. 11, 1037-1040 (2014). [6] K. Wang, W. Sun, C. T. Richie, B. K. Harvey, E. Betzig, N. Ji, Nature Comm. 6, 7276 (2015).
19
Session: TUE-PL03 TUE-PL03
Date: March 22 (Tuesday) Time: 13:30-15:00 Session Chair: % @ 8 ;= I ?. 0 7 . 1 . < @ 0 7 ] ] Room: Plenary Session
Prof. Chennupati Jagadish
Australian Laureate Fellow and Distinguished Professor Australian National University, Australia
Semiconductor Nanowires for Optoelectronics March 22, 2016 13:30-14:15 and Energy Applications International Conference Hall (4F)
Biography for Chennupati Jagadish
Professor Jagadish is a Distinguished Professor and Head of Semiconductor Optoelectronics and Nanotechnology Group in the Research School of Physics and Engineering, Australian National University. He is the Director of Australian National Fabrication Facility, ACT node, Convener of Australian National Fabrication Facility. He is also serving as Vice-President and Secretary Physical Science of the Australian Academy of Science. Prof. Jagadish is an Editor/Associate editor of 6 Journals, 3 book series and serves on editorial boards of 17 other journals. He has published more than 820 research papers (550 journal papers), holds 5 US patents, co-authored a book, co-edited 6 books and edited 12 conference proceedings and 15 special issues of Journals. He won the 2000 IEEE Millennium Medal and received Distinguished Lecturer awards from IEEE Nanotechnology Council, IEEE Photonics Society and IEEE Electron Devices Society. He is a Fellow of the Australian Academy of Science, Australian Academy of Technological Sciences and Engineering, IEEE, APS, MRS, OSA, AVS, ECS, SPIE, AAAS, IoP (UK), IET (UK), IoN (UK) and the AIP. He received Peter Baume Award from the ANU in 2006, the Quantum Device Award from ISCS in 2010, IEEE Photonics Society Distinguished Service Award in 2010, IEEE Nanotechnology Council Distinguished Service Award in 2011 and Electronics and Photonics Division Award of the Electrochemical Society in 2012, 2013 Walter Boas Medal from Australian Institute of Physics, 2015 IEEE Pioneer Award in Nanotechnology, 2015 IEEE Photonics Society Engineering Achievement Award and 2016 Silver Jubilee International Award from Materials Research Society of India. He has received prestigious Australian Laureate Fellowship and Australian Federation Fellowship from the Australian Government.
22 PL-4
Semiconductor Nanowires for Optoelectronics and Energy Applications
Chennupati Jagadish Australian National University, Research School of Physics and Engineering, Canberra, ACT 2601, Australia E-mail address: [email protected]
Abstract: Semiconductor optoelectronic devices such as lasers and terahertz detectors based on nanowires will be discussed. Nanowire plasmonics and nanowire solar cells will be discussed and future prospects of nanowires will be presented.
Semiconductor nanowires are considered as building blocks for the next generation electronics and photonics. Controlling the size, shape and composition of nanowires is critical to engineer their electronic and optical properties. A wide variety of III-V semiconductor nanowires and their axial and radial heterostructures will be discussed. Vapour liquid solid (VLS) growth and selected area epitaxy (SAE) of nanowires will be discussed. Role of surface recombination on light emission properties and how to engineering non- radiative recombination pathways will be presented [1,2]. Nanowire quantum well tube structures and effect of engineering well thickness on light emission wavelength will be discussed [3,4]. \ ' [ modes and hybrid photonic and plasmonic modes will be discussed [5,6]. Semiconductor nanowire lasers based on GaAs and InP system will be presented including [ *+ <= single nanowires will be discussed and role of antenna structures on bandwidth of these detectors will be presented [9]. Nanowire solar cells and light concentration effects in nanowire solar cells will be discussed and challenges in device fabrication will be presented [10]. Engineering of neuronal networks using nanowires will be presented and role of three- dimensional morphology of nanowire structures on neuron growth will be presented. Finally, future prospects of nanowires for optoelectronic devices will be discussed.
[1] H.J. Joyce et al, Nano Letters 7, 921 (2007) [2] N. Jiang et al Nano Letters 13, 5135 (2013) [3] M. Fickenscher et al, Nano Letters 13, 1016 (2013) [4] T. Shi et al, Nano Letters 15, 1876 (2015) [5] S. Mokkapati et al, Nano Letters 12, 6428 (2012) [6] S. Mokkapati et al, Nano Letters 15, 307 (2015) [7] D. Saxena et al Nature Photonics (2013) [8] Q.Gao et al, Nano Letters 14, 5206 (2014) [9] K. Peng et al Nano Letters 15, 206 (2015) [10] P. Parkinson et al, Nano Letters 13, 1405 (2013)
23 Plenary Session
Prof. Vladimir Shalaev
Distinguished Professor Purdue University, USA
March 22, 2016 New Materials Platforms for Nanophotonics 14:15-15:00 International Conference Hall (4F)
Biography for Vladimir Shalaev
Vladimir (Vlad) M. Shalaev, Scientific Director for Nanophotonics in Birck Nanotechnology Center and Distinguished Professor of Electrical and Computer Engineering at Purdue University, specializes in nanophotonics, plasmonics, and optical metamaterials. Vlad Shalaev received several awards for his research in the field of nanophotonics and metamaterials, including the Max Born Award of the Optical Society of America for his pioneering contributions to the field of optical metamaterials, the Willis E. Lamb Award for Laser Science and Quantum Optics, Rolf Landauer medal of the ETOPIM (Electrical, Transport and Optical Properties of Inhomogeneous Media) International Association, the UNESCO Medal for the development of nanosciences and nanotechnologies and IEEE Photonics Society William Streifer Scientific Achievement Award, He is a Fellow of the IEEE, APS, SPIE, MRS and OSA. Prof. Shalaev authored three books, twenty- seven invited book chapters and over 400 research publications.
24 PL-5
New Materials Platforms for Nanophotonics
Vladimir M. Shalaev and Alexandra Boltasseva Purdue University Email: [email protected]
Over the past decade, one of the major focal points for the area of nanophotonics has been developing a new class of “plasmonic” structures and “metamaterials” as potential building blocks for advanced optical technologies, including data processing, exchange and storage; a new generation of cheap, enhanced-sensitivity sensors; nanoscale-resolution imaging techniques; new concepts for energy conversion with improved solar cells and thermophotovoltaic devices, as well as novel types of light sources. Designing plasmonic metamaterials with versatile properties [ % However, to enable these new technologies based on plasmonics, grand limitations associated with the use of metals as constituent materials must be overcome. In the structures demonstrated so far, too much light is absorbed in the metals (such as silver and gold) commonly used in plasmonic metamaterials. The fabrication and integration of metal nanostructures with existing semiconductor technology is challenging, and the materials need to be more precisely tuned so that they possess the proper optical properties to enable the required functionality. Our recent research aims at developing novel plasmonic materials (other than the metals used so far) that will form the basis for future low-loss, CMOS-compatible devices that could enable full-scale development of the plasmonic and metamaterial technologies. In this work, we replace metals in plasmonic metamaterials by new plasmonic ceramics such as transition metal nitrides, whose properties resemble those of gold. However, unlike gold, these materials have adjustable/ tunable optical properties, they are cost-effective, robust, refractory (withstanding very high temperatures) and compatible with standard semiconductor processing. Here, we will demonstrate that titanium nitride’s addition to the short list of plasmonic materials paves the way to a new class of data recording systems and CMOS-compatible, on-chip hybrid nanophotonic devices with unprecedented compactness, speed, and efficiency as well as to novel energy conversion schemes. Another important class of plasmonic materials is based on switchable and tunable transparent conducting oxides that can also broaden the family of novel plasmonic materials for nanophotonics. In this talk, the new material platform as well as novel designs and concepts for nanophotonic devices, data storage and energy conversion will be discussed.
25
Session: TUE-PL04
Date: March 22 (Tuesday) Time: 15:30-17:30 Session Chair: 8 ] != %=! ` .
R % % ? 1 TUE-PL04 Room: Plenary Session
Prof. Nikolay Zheludev
University of Southampton, UK
March 22, 2016 Metamaterials: Optical Properties on Demand 15:30-16:15 International Conference Hall (4F)
Biography for Nikolay Zheludev
Professor Nikolay Zheludev’s research interest are in nanophotonics and metamaterials. He is the Director of the Centre for Photonic metamaterials and Deputy Director of the Optoelectronics Research Centre in Southampton University, UK. He is also co-Director of The Photonics Institute and directs the Centre for Disruptive Photonic Technologies at Nanyang Technological University.
His personal awards include the Thomas Young medal (IOP) for “global leadership and pioneering, seminal work in optical metamaterials and nanophotonics”, the Leverhulme Trust Senior Research Fellowship; Senior Research Professorship of the EPSRC; The Royal Society Wolfson Research Merit Award & Fellowship. He is a Fellow of the European Physical Society (EPS), the Optical Society (OSA) and the Institute of Physics (London).
He is Editor-in-Chief of the Journal of Optics (IOP) and an Advisory Board Member for Nanophotonics, ACS Photonics and Nature Publishing Group Scientific Reports. In 2007 created European Physical Society international meeting at the crossroads of nanophotonics and metamaterials, NANOMETA. He was among a small group of research community leaders who provided initial impetus to the International Year of Light, declared by United Nations for 2015.
28 PL-6
Metamaterials: Optical Properties on Demand
Nikolay I. Zheludev 1,2 1Centre for Photonic Metamaterials and Optoelectronics Research Centre, University of Southampton, UK www.nanophotonics.org.uk 2 TPI & Centre for Disruptive Photonic Technologies, NTU, Singapore www.nanophotonics.sg E-mail: [email protected]
Abstract: The next grand challenge for nanophotonics is to develop metamaterials with on-demand optical properties “on demand” when every individual metamolecule may be independently controlled at any given point in space and at any moment of time. This will allow not only the modulation of light’s intensity or phase, but will offer control of the wavefront and #[ [ and multi-channel data processing in meta-systems. We report how randomly reconfigurable metadevices can be achieved with nano-opto-mechanical, phase change and coherent control technologies.
N.I.Zheludev. Obtaining optical properties on demand. Science. 348, 973 (2015)
29 Plenary Session
Prof. Harald Giessen
University of Stuttgart, Germany
Short-range surface plasmonics and its (sub-) March 22, 2016 16:15-17:00 femtosecond dynamics International Conference Hall (4F)
Biography for Harald Giessen
Harald Giessen (*1966) graduated from Kaiserslautern University with a diploma in Physics and obtained his M.S. and Ph.D. in Optical Sciences from the University of Arizona in 1995. After a postdoc at the Max-Planck-Institute for Solid State Research in Stuttgart he moved to Marburg as assistant professor. From 2001-2004, he was associate professor at the University of Bonn. Since 2005, he is full professor and holds the Chair for Ultrafast Nanooptics in the Department of Physics at the University of Stuttgart. He is also co-chair of the Stuttgart Center of Photonics Engineering, SCoPE. He was guest researcher at the University of Cambridge, and guest professor at the University of Innsbruck and the University of Sydney, at A*Star, Singapore, as well as at Beijing University of Technology. He is associated researcher at the Center for Disruptive Photonic Technologies at Nanyang Technical University, Singapore. He received an ERC Advanced Grant in 2012 for his work on complex nanoplasmonics. He is on the advisory board of the journals "Advanced Optical Materials", "Nanophotonics: The Journal", and "ACS Photonics". He is a topical editor for ultrafast nanooptics, plasmonics, and ultrafast lasers and pulse generation of the journal "Light: Science & Applications" of Nature Publishing Group. He is a Fellow of the Optical Society of America.
30 PL-7
31 Invited talk
The University of Hong Kong, Hong Kong
Perovskite solar cells-optimizing the perovskite March 22, 2016 and device fabrication 17:00-17:30 International Conference Hall (4F)
% @ 8 ;= I .8 ;8 . . Electrical Engineering, the University of Belgrade in 1997. After finishing her PhD studies, she worked as a postdoctoral fellow at University of Hong Kong and as an Alexander von Humboldt postdoctoral fellow at TU Dresden. She joined the Dept. of Physics at the University of Hong Kong in 2003 as assistant professor and she is currently a professor. Her research interests include nanomaterials, wide-bandgap semiconductors, and organic materials, and their applications in areas related to energy and environment, such as photocatalysis, antimicrobial materials, solar cells, and batteries. She has published 259 research articles including reviews, and has been cited over 9800 times. Her h-index is 47.
32 IN-2
Perovskite solar cells – optimizing the perovskite and device fabrication
Fangzhou Liu,1 Qi Dong,1 Man Kwong Wong,1 Aleksandra B. Djuriši ,1* Annie Ng,2 Zhiwei Ren,2 Qian Shen,2 Charles Surya2 U C F S C F 0 U C F C C F C F
Abstract: Perovskite solar cells are highly promising emerging photovoltaics technology, with reported efficiencies exceeding that of amorphous Si technology and approaching that of other established inorganic thin film technologies. The perovskite films, however, are highly sensitive to the preparation conditions, and they can degrade upon exposure to moisture, which is accelerated by illumination. Consequently, it is necessary to achieve significant improvements in understanding the relationship between the preparation conditions, films properties, photovoltaic performance and long term stability. We discuss the effect of film preparation conditions and device architecture on the efficiency and stability of perovskite solar cells.
1. Introduction Perovskite solar cells have been attracting increasing attention since the first reports with the efficiency of ~10% in 2012 [1,2]. The efficiency of the devices has now exceeded 20%, and there is lots of ongoing work to further improve the efficiency, as well as address the significant concern of the device stability. The perovskite solar cells can be prepared by both solution methods and evaporation [3,4]. We have investigated the preparation of the perovskite film by a two-step solution method on different metal oxides as electron transport layers and using different film preparation conditions. Both the underlying metal oxide film as well as perovskite synthesis conditions significantly affect the film properties, and consequently the device performance.
2. Results and Discussion We found that the perovskite film morphology is strongly dependent on the underlying metal oxide film, with films prepared on ZnO typically exhibiting pinholes resulting in lower device efficiency. On commonly used TiO2 electron transport layer, perovskite synthesis conditions affect the film composition (presence or absence of the small amount of PbI2) and the film morphology (grain size, presence of pinholes) [5]. This in turn affects the device efficiency, as well as stability. With appropriate encapsulations, perovskite cells exhibiting power conversion efficiency above 90% of the initial one after over a week of storage in ambient with 10 h of constant simulated solar illumination daily can be achieved.
3. References [1] H.-S. Kim, C.-R. Lee, J.-H. Im, K.-B. Lee, T. Moehl, A. Marchioro, S.-J. Moon, R. Humphry-Barker, J.-H. Yum, J. E. Moser, M. Grätzel, N.-G. Park, Sci. Rep. 2, 591 (2012). [2] M. M. Lee, J. Teuscher, T. Miyasaka, T. N. Murakami, H. J. Snaith, Science 338, 643-647 (2012). [3] Z.-W. Ren, A. Ng, Q. Shen, H. C. Gokkaya, J. C. Wang, L. J. Yang, W. K. Yiu, G. X. Bai, A. B. Djuriši4, W. K. Chan, W. W. F. Leung, J. H. Hao, W. K. Chan, C. Surya, Sci. Rep. 4, 6752 (2014). [4] A. Ng, Z.-W. Ren, Q. Shen, S. H. Cheung, H. C. Gokkaya, G. X. Bai, J. C. Wang, L. J. Yang, S. K. So, A. B. Djuriši4, W. W. F. Leung, J. H. Hao, W. K. Chan and C. Surya, J. Mater. Chem. A 3, 9223-9231 (2015). [5] F. Z. Liu, Q. Dong, M. K. Wong, A. B. Djuriši4, A. Ng, Z. W. Ren, Q. Shen, C. Surya, W. K. Chan, J. Wang, A. M. C. Ng, C. Z. Liao, H. K. Li, K. M. Shih, submitted, 2015.
33
WED-PL01
Session: WED-PL01
Date: March 23 (Wednesday) Time: 08:15-09:00 Session Chair: . ` 0 7 ] ] Room: Plenary Session
Prof. Satoshi Kawata
Distinguished Professor Osaka University, Japan
March 23, 2016 Optical 3D nano-fabrication: drawing or growing? 08:15-09:00 International Conference Hall (4F)
Biography for Satoshi Kawata
Professor Satoshi Kawata is a Distinguished Professor of Osaka University, the President of JSAP (Japan Society of Applied Physics), and the Chairman of Nanophoton Corporation. He has been a Professor of Department of Applied Physics and Frontier Bioscience in Osaka University since 1993, and a Chief Scientist at RIKEN from 2000 to 2012. He founded the Photonics Center in Osaka University in 2007 and has been the Executive Director till 2015. He has served as the Editor of Optics Communications from 2000 to 2009, the President of Japanese Spectroscopical Society from 2007 to 2008. He is one of the pioneers in near-field optics and plasmonics (tip- enhanced Raman microscopy, evanescent-photon manipulation of nano/micro particles, plasmon holography) and three-dimensional nano-fabrication (two-photon polymerization, isomerization and reduction). He has also contributed to the fields of bio-photonics, molecular spectroscopy (Raman, UV, NIR, etc.), and signal recovery. He is a Fellow of OSA, IOP, SPIE, and JSAP.
36 PL-8
Optical 3D nano-fabrication: drawing or growing?
Satoshi Kawata Osaka University [email protected]
\ # [ of science and industry, it is limited to surface science and technology in 2D using e-beam, ion- # [ of the surface. Available nanotech devices such as nano-electronic circuits, high-density data- storage, liquid-crystal displays, MEMSs and NEMSs are all basically in two dimensions. Here, I discuss on the methods of 3D fabrication in nano-scale. Two-photon process has been successfully combined with photo-polymerization for drawing micro- and nano-machines in 3D with a tightly focused laser beam [1]. It has been applied to photo-isomerization for 3D optical data-storage [2]. Metallic 3D structures have been drawn with two-photon photo-reduction, which could be used for 3D metamaterials [3]. The other method of 3D fabrication is based on bottom- up approach. Fiber structures have been self-grown in polymerizable resin [4]. Coupling and [ [ nonlinear Schrödinger equations. Metallic fractal nano-structures in 3D have been also grown in silver-ion solution with plasmonic heating of metallic nano-seeds [5].
References [1] S. Kawata, et. al, Nature ^_` {|+%{|< `_ [2] S. Kawata and Y. Kawata, Chem Rev. 88, 083110, 2006. [3] Y. -Y. Cao, et. al., Small 5, 1144-1148, 2009 [4] S. Shoji and S. Kawata, Appl. Phys. Lett. 75, 737-739, 1999. [5]N. Takeyasu, N. Nishimura, S. Kawata, submitted.
37
WED-IC-S1
Session: WED-IC-S1
Date: March 23 (Wednesday) Time: 09:10-10:10 Session Chair: 07 ?. 1 0 7 ] . R ` ? 0 7 ? 1 Room: Invited talk
Prof. Anatoly Zayats
King’s College London, UK
March 23, 2016 Nonlinear Processes in Plasmonic Metamaterials 09:10-09:40 International Conference Hall (4F)
Biography for Anatoly Zayats
Professor Anatoly V. Zayats is the head of the Experimental Biophysics and Nanotechnology Group at the Department of Physics, King’s College London, where he also leads Nano-optics and Near-field Spectroscopy Laboratory. He graduated and received PhD in Physics from Moscow Institute of Physics and Technology. His current research interests are in the areas of nano-optics, scanning probe microscopy, nanophotonics and plasmonics, metamaterials, nonlinear optics and spectroscopy, surface plasmons and polaritons, and optical properties of surfaces, thin films, semiconductors and low-dimensional structures. He is a holder of the Royal Society Wolfson Research Merit Award, a Fellow of the Institute of Physics, the Optical Society of America, SPIE and the Royal Society of Chemistry.
40 IN-3
Nonlinear Processes in Plasmonic Metamaterials
G. Sartorello, G. Marino, M. E. Nasir, A. Neira, S. Peruh, N. Olivier, A. V. Krasavin, W. Dickson, G. A. Wurtz, A. V. Zayats
Abstract: Hyperbolic plasmonic metamaterials open up possibility to engineer the effective bulk plasma frequency and enhanced second- and third-order nonlinear response in the desired spectral range. Here we overview the second-harmonic generation and Kerr-type nonlinearity of plasmonic nanorod metamaterials in visible and telecom wavelength range.
Metals exhibit strong and fast nonlinearities making metallic, plasmonic, structures very promising for ultrafast all-optical applications at low light intensities [1]. Combining metallic nanostructures in metamaterials provides additional functionalities via prospect of precise engineering of spectral response and dispersion. From this point of view, hyperbolic metamaterials, in particular those based on plasmonic nanorod arrays, provide wealth of exciting possibilities in nonlinear optics offering designed linear and nonlinear properties, polarization control, spontaneous emission control and many others [1,2]. These properties can be designed as required at a given frequency range by controlling the effective plasma frequency of metamaterial [3] and the field distribution associated with meta-atoms [4], as well as the mode structure of the metamaterial waveguides [5,6]. Experiments and modeling have already demonstrated very strong Kerr-nonlinear response and its ultrafast recovery due to the nonlocal nature of the plasmonic mode of the metamaterial, so that small changes in the permittivity of the metallic component under the excitation modify the nonlocal response that in turn leads to strong changes of the metamaterial transmission. In this talk, we will discuss experimental studies and numerical modeling of second- and third-order nonlinear optical processes in hyperbolic metamaterials based on metallic nanorods and other plasmonic systems where coupling between the resonances plays important role in defining nonlinear response [7-12]. Second-harmonic generation and ultrafast Kerr-type nonlinearity originating from metallic component of the metamaterial will be considered, including nonlinear magneto-optical effects. Nonlinear optical response of stand-alone as well as integrated metamaterial components will be presented. Some of the examples to be discussed include nonlinear polarization control, nonlinear metamaterial integrated in silicon photonic circuitry and second-harmonic generation, including magneto-optical effects.
[1] M. Kauranen and A.V. Zayats, “Nonlinear plasmonics,” Nat. Phot. 6, 737 (2012) [2] A.V. Zayats and S. A. Maier, Eds., Active Plasmonics and Tuneable Plasmonic Metamaterials (New York: Wiley, 2013) [3] M. E. Nasir et al, “Tuning the effective plasma frequency of nanorod metamaterials from visible to telecom wavelengths,” Appl. Phys. Lett. 107, 121110 (2015) [4] K.-T. Tsai et al, “Looking into meta-atoms of plasmonic nanowire metamaterial,” Nano Letters 14, 4971 (2014) [5] N. Vasilintonakis et al., “Bulk plasmon-polaritons in hyperbolic nanorod metamaterial waveguides,” Laser Phot. Rev. 9, 345 (2015) [6] W. Dickson et al, “Hyperbolic polaritonic crystals based on nanostructured nanorod metamaterials,” Adv. Mat. DOI: 10.1002/adma.201501325 (2015) [7] G.A. Wurtz et al, “Designed ultrafast optical nonlinearity in a plasmonic nanorod metamaterial enhanced by nonlocality,” Nat. Nanotech. 6, 107 (2011) [8] P. Ginzburg, et al, “Manipulating polarization of light with ultrathin epsilon-near-zero metamaterials,” Opt. Exp. 21, 14907 (2013) [9] A. D. Neira et al, “Ultrafast all-optical modulation with hyperbolic metamaterial integrated in Si photonic circuitry,” Opt. Express 22, 10987 (2014) [10] V.L. Krutyanskiy et al, “Plasmonic enhancement of the nonlinear magneto-optical response of nickel nanorod metamaterials,” Phys. Rev. B 87, 035116 (2013) [11] A. D. Neira et al, “Eliminating material constraints for nonlinearity with plasmonic metamaterials,” Nat. Comm. 6, 7757 (2015) [12] G. Marino et al., “Second-harmonic generation from hyperbolic plasmonic metamaterial slab,” arXiv:1508.07586 (2015)
41 Invited talk
Dr. Gary P. Wiederrecht
Argonne National Laboratory, USA
Nanophotonic Materials for Enhanced Ultrafast March 23, 2016 09:40-10:10 Optical Response and Efficient Energy Propagation International Conference Hall (4F)
Biography for Gary P. Wiederrecht
Gary Wiederrecht received a B.S. degree in chemistry from UC Berkeley in 1987 and a Ph.D. in physical chemistry from MIT in 1992. He moved to Argonne National Laboratory as a postdoctoral fellow in 1992 and became a scientific staff member in 1995. Since 2007, he has served as the Group Leader of the Nanophotonics Group in the Center for Nanoscale Materials. He became a Senior Scientist in 2013. His research interests center on energy conversion and the ultrafast photochemistry and photophysics of hybrid nanostructures.
42 IN-6
Nanophotonic Materials for Enhanced Ultrafast Optical Response and Efficient Energy Propagation
Gary P. Wiederrecht Center for Nanoscale Materials, Argonne National Laboratory, Argonne, IL 60439 E-mail address: [email protected]
Abstract: We describe the development of hybrid nanostructures for nanophotonics. Different elements are described to support long-range energy transport in nanostructures, or to produce ultrafast optical modulation. Efforts to image energy propagation with sub- wavelength spatial resolution are also detailed.
1. Introduction Future nanophotonic architectures for optical energy conversion and photocatalysis will require nanostructures with roles that work together cooperatively, such as structures with a large absorption cross sections combined with features that enable guiding, propagating, and converting energy. Ultrafast optical responses in nanostructures are critical to understand for these applications. Although there is the potential for radiative and nonradiative energy losses, there is also the opportunity for accessing pathways for improved energy conversion, such as through the extraction of hot plasmonic electrons from metal nanoparticles [1]. For propagation of energy in nanophotonic structures, nanostructured materials inspired by natural photosynthetic membranes represent an opportunity for efficient and directional energy transport. In natural photosystems, light harvesting complexes can transport excitons to the reaction center core with near unity conversion of absorbed photons to separated charge. A key to this process is the high rate of exciton hopping and the directionality of exciton flow due to an energy level waterfall effect of excitons in complexes as the reaction center core is approached. Efforts to induce similar behavior in biomimetically inspired nanostructures are described [2-3]. The unique optical and electronic properties of nanostructured materials that are advantageous for both solar energy concentration and conversion are further described. This is followed with a specific description of the confinement of light via cavity modes in bilayer films of nanoscale thickness. The potential impact of cavity modes in ultrathin films on the design of solar concentrators is described, and the application to a new - 0 1 2 is introduced [4]. By spatially varying the thickness of the film so that the bilayer cavity undergoes a resonance shift, near-lossless propagation and collection of emission is observed. The prospects and necessary improvements for further utilization of RSLSCs are discussed. For energy conversion, I discuss our efforts to temporally and spatially resolve exciton generation and charge separation in photovoltaic heterostructures, beginning with the initial absorption of photons to create an electron-hole pair, to the generation and transport of free charge carriers. Specifically, the use of an ultrafast Stark shift in excitonic molecular aggregates to monitor charge separation and photovoltaic field formation in nanoscale heterostructures is described [5]. Finally, efforts to image exciton flow in nanoscale materials through near-field optical microscopy are detailed. Use of the Center for Nanoscale Materials was supported by the U. S. Department of Energy, Office of Science, Office of Basic Energy Sciences, under Contract No. DE-AC02-06CH11357.
2. References [1] H. Harutyunyan, A. B. F. Martinson, D. Rosenmann, L. K. Khorashad, L. V. Besteiro, A. O. Govorov, G. P. Wiederrecht, Nat. Nanotech. 10, 770 (2015). [2] H.-J. Son, S. Jin, S. Patwardhan, S. Wezenberg, N.C. Jeong, M. So, C. Wilmer, A. Sarjeant, G. Schatz, R. Snurr, O. Farha, G. P. Wiederrecht, J. Hupp, J. Am. Chem. Soc. 135, 862 (2013). [3] S. Jin, H.-J. Son, O.K. Farha, G.P. Wiederrecht, J.T. Hupp, J. Am. Chem. Soc. 135, 955 (2013). [4] N. C. Giebink, G. P. Wiederrecht, and M. R. Wasielewski, Nature Photon. 5, 694 (2011). [5] G. P. Wiederrecht, N. C. Giebink, J. Hranisavljevic, D. Rosenmann, A.B.F. Martinson, R. D. Schaller, and M. R. Wasielewski, Appl. Phys. Lett. 100, 113304 (2012).
43
Session: WED-R1-S1 WED-R1-S1
Date: March 23 (Wednesday) Time: 09:10-10:10 Session Chair: = _ 0 7 % R . ` ? 1 ! 0 7 ? 1 Room: 1st Conference Room (3F) Invited talk
Prof. Prabhat Verma
Osaka University, Japan
High-Resolution Nanoimaging with Tip-Enhanced March 23, 2016 09:10-09:40 Raman Spectroscopy 1st Conference Room (3F)
Biography for Prabhat Verma
Prabhat Verma is a currently a full professor at the department of Applied Physics and a member of Photonics Center at Osaka University. He also holds the positions of the Vice-Chair of the Asian Core Program and the Chair of the International Committee at the Photonics Center of Osaka University, and a Director of the Japan Society of Applied Physics. He received his doctorate from IIT Delhi, India, and did post doctoral research in Germany and Japan, before he moved to Osaka University. He is presently working in the fields of nanospectroscopy, nanoimaging, SERS, TERS, metamaterials, and related topics. He has co-authored a number of papers in journals such as Nature Photonics, Nature Communications, PRL, ACS Nano, PRB, and other high impact journals. He is also involved in a number of activities in various international scientific societies and communities.
46 IN-4
High-Resolution Nanoimaging with Tip-Enhanced Raman Spectroscopy
Prabhat Verma Department of Applied Physics, Osaka University, Suita, Osaka, Japan E-mail address: [email protected]
Abstract: The diffraction limit of light restricts spatial resolution in optical imaging to about half of the wavelength. Tip-enhanced Raman spectroscopy, where light is enhanced and strongly confined within the volume of a few nanometers, can go well beyond the diffraction limit and allows us to study and image a sample with a spatial resolution of a few nanometers.
Nature has many interesting things to offer - one of them is the fact that visible light (from near-UV to near-IR) contains an energy that is comparable to the electronic or vibrational energies of most of the naturally existing materials that we interact with in our day-to-day lives. Visible light can therefore interact directly with the electronic or vibronic system of a sample, and can extract rich information related to the intrinsic properties of the sample. This is probably one of the most important reasons why optical techniques, such as Raman spectroscopy, have always been convenient tools for analyzing and imaging various materials. However, Raman microscopy in its conventional form is not suitable for analyzing and imaging nanomaterials due to two major reasons. First, the poor spatial resolution restricted by the diffraction limits of the probing light, makes it impossible to analyze materials smaller than about half of the wavelength. And second, due to the extremely small volume of nanomaterials, Raman scattering intensity is extremely weak for such samples. However, when conventional Raman microscopy is combined with the near-field techniques, it achieves new and exciting features as it goes beyond the conventional limits of optical microscopy, in terms of both the spatial resolution and scattering intensity. This can be done by utilizing the technique of tip-enhanced Raman spectroscopy (TERS), which is based on plasmonic enhancement and confinement of light field near the apex of a sharp metallic nanotip for characterizing and imaging samples at nanoscale. This plasmonics-based technique allows us to have a spatial resolution down to about 10 nm in optical nanoimaging [1-4]. Here, I will show how such a high spatial resolution in TERS is obtained and how it can be useful in various applications. The spatial resolution, however, can be further improved if we combine TERS with some other mechanism. One of such examples is the inclusion of tip-applied pressure in TERS, which distorts the sample locally. Owing to the sharp curvature of the tip apex, the contact area between the tip and the sample can be extremely small, ideally of molecular level. By optically sensing this localized distortion, which is confined within the volume much smaller than the confined field, one can obtain super high resolution. In recent studies, resolution better than 4 nm was demonstrated though this imaging [5]. Further, TERS can also realize polarization dependent optical imaging at nanoscale [6]. This can be very useful for investigating linear molecules, such as in organic-semiconductor-based or carbon-nanotube-based nano-devices. I will also discuss some techniques to obtain background-free nanoimaging in TERS.
[1] S. Kawata, Y. Inouye, and P. Verma, Nature Photon. 3, 388 (2009). [2] P. Verma et al., Laser & Photon. Rev. 4, 548 (2010). [3] Y. Okuno, Y. Saito, S. Kawata and P. Verma, Phys. Rev. Lett. 111, 21601 (2013). [4] J. Yu et al., Appl. Phys. Lett. 102, 123110 (2013). [5] T. Yano et al., Nature Photon. 3, 473 (2009). [6] T. Mino et al., ACS Nano 8, 10187 (2014).
47 Invited talk
Prof. Kosei Ueno
Hokkaido University, Japan
Plasmon-enhanced photochemistry using nano- March 23, 2016 09:40-10:10 engineered gold particles 1st Conference Room (3F)
Biography for Kosei Ueno
Kosei Ueno is an associate professor at the Research Institute for Electronic Science of Hokkaido University, Japan. He received his Ph.D. in chemistry from Hokkaido University in 2004. From 2004 to 2006, he worked in Professor Hiroaki Misawa’s laboratory as a JSPS research fellow. He became an assistant professor at Hokkaido University in 2006 and was promoted to associate professor in 2008. From 2007 to 2014, he held an additional post as a PRESTO researcher at the Japan Science & Technology Agency (JST). From 2010 to 2012, he was a visiting associate professor at the Institute for Molecular Science, Japan. He studies surface plasmon-assisted nanolithography based on plasmon-enhanced photochemical reactions and surface-enhanced spectroscopy in the infrared wavelength and terahertz frequency region.
48 IN-7
Plasmon-enhanced photochemistry using nano- engineered gold particles
Kosei Ueno Research Institute for Electronic Science, Hokkaido University E-mail address: [email protected]
Abstract: We are studying surface plasmon photonics from the viewpoint of chemical applications using precisely controlled metallic nanostructures. The characteristic points of nanoplasmonics is to localize electromagnetic field at a nanometer-sized spatial domain (hot site) and induce an enormous enhancement as well as a steep gradient of electromagnetic field near the hot site. Therefore, various applications can be considered such as plasmonic lithography, chemical or optical sensors, light-energy conversion systems, and so forth. In this presentation, our representative studies related to chemical applications of plasmonics are demonstrated.
1. Plasmon-assisted nanolithography A novel lithography system appropriate for the formation of various shapes of nanopatterns on a positive photoresist film at a nanometer accuracy is demonstrated (Fig. 1). To form nano- patterns based on a photomask design, we utilized a higher-order localized surface plasmon resonance mode. This mode was used to produce homogeneous scattering light that propagates the photoresist film [1]. The essential aspect of forming fine nano- patterns is to utilize photochemical reactions of the photoresist via a two-photon absorption process [2]-[4].
2. Far-infrared optical sensor using plasmon-induced radiation force Far infrared optical sensor working on the principle of volume Fig. 1. SEM images of nanopatterns formed on phase transition of polymer gel triggered by plasmon-induced the positive photoresist surface by plasmon- radiation force is also demonstrated. Closely-spaced gold assisted nanolithography. nanostructures whose plasmon resonant wavelength is far-infrared region was fabricated on a silicon substrate as an optical antenna. We explored the volume phase transition of polyacrylamide gel induced by plasmon- induced radiation force in detail and elucidated the possibility of application to optical sensor in far-infrared region.
3. Surface-enhanced THz spectroscopy Highly-sensitive Terahertz time-domain spectroscopy (THz-TDS) is also demonstrated. The advantage of THz-TDS can pursue not only the spectrum related to molecular fingerprints but also intermolecular interactions such as hydrogen bond and van der Waals force analogous to neutron scattering spectroscopy including information about molecular motions. However, the main drawback of the THz-TDS system is less spatial resolution and sensitivity. Recently, we have successfully elucidated the phenomenon that the signals are extraordinarily enhanced by plasmonic effect and constructed surface-enhanced THz-TDS system [5].
4. Acknowledgements The author is very grateful to Prof. H. Misawa, Mr. K. Onishi, Mr. S. Takabatake, Mrs. H. Itoh, Mrs. W. Nakano, and Mr. S. Nozawa at Hokkaido University for their experimental contributions and fruitful discussions.
5. References [1] K. Ueno, S. Takabatake, K. Onishi, H. Itoh, Y. Nishijima, H. Misawa, Appl. Phys. Lett., 99, 011107 (2011). [2] K. Ueno, S. Takabatake, Y. Nishijima, V. Mizeikis, Y. Yokota, H. Misawa, J. Phys. Chem. Lett., 1, 657-662 (2010). [3] K. Ueno, S. Juodkazis, T. Shibuya, Y. Yokota, V. Mizeikis, K. Sasaki, H. Misawa, J. Am. Chem. Soc., 130, 6928-6929 (2008). [4] K. Ueno, S. Juodkazis, T. Shibuya, V. Mizeikis, Y. Yokota, H. Misawa, J. Phys. Chem. C, 113, 11720-11724 (2009). [5] K. Ueno, S. Nozawa, H. Misawa, Opt. Express, 23, 28584-28592 (2015).
49
Session: WED-R2-S1
Date: March 23 (Wednesday) Time: 09:10-10:10
Session Chair: Ann Roberts (The University of Melbourne, Australia) WED-R2-S1 . R 1 ` ? 1 0 7 ? . 7 ? 1 Room: 2nd Conference Room (3F) Invited talk
Prof. Ai Qun Liu
Nanyang Technological University, Singapore
March 23, 2016 Meta-fluidic Metasurface 09:10-09:40 2nd Conference Room (3F)
Biography for Ai Qun Liu
Dr Ai-Qun Liu (A. Q. Liu) (http://nocweba.ntu.edu.sg/laq_mems/) received his PhD degree from National University of Singapore (NUS) in 1994. Currently, he is a Professor at School of Electrical & Electronic Engineering, Nanyang Technological University (NTU). He serves as an editor and editorial board member of several journals. He is the author or co-author of over 150 publications including peer-reviewed journal papers and two books. Also, he is a SPIE Fellow and RCS Fellow.
52 IN-5
Meta fluidic Metasurface
Ai Qun Liu1,2, Z. H. Yang2 and 1School of Electrical & Electronic Engineering, Nanyang Technological University, Singapore " U U ([email protected])
Metasurface and meta-fluidic materials aim at manipulating light and metal-liquid flow in the microchannel and exploiting their interaction to create highly versatile devices have received significant scientific interests in many areas. The novelties of the integrated opto-fluidic and meta-fluidic materials are two-fold. First, metal-fluids can be used to carry substances for analysis in highly sensitive optical micro- devices. Second, metal-fluids can also be exploited to control light, making them tunable, reconfigurable and adaptive. In this paper, the state-of-the-art of meta-fluidic-material research is reviewed with breakthrough innovations in optical and photonic devices, including the high potential applications of meta-fluidic material in biophysical, biochemistry and biomedical studies [1-3]. Opto-fluidic and meta-fluidic materials represents a new paradigm for designing light-manipulating devices, such as cloaks, transformation optics and field concentrators, through the engineering of electromagnetic space using materials with spatially variable parameters. We demonstrate that a laminar metal-liquid flow in microfluidic channel exhibits spatially variable dielectric properties that support novel wave-focusing and interference phenomena [4]. This work provides new insight into the unique optical properties of meta-fluidic devices and their potential applications [5-6]. Opto-fluidic and meta-fluidic materials is not only to change the material properties through tuning or reconfiguring the unit element structure size or shapes, which is changed by the metal-liquid flow in the microchannel. It is significant breakthrough research for the meta-fluidic material to demonstrate new materail with new physics phenomena that are never been observed before. In the paper, the different types of meta-fluidic-material will be presented with some future industry applications.
[1] A. Q. Liu, H. J. Huang, L. K. Chin, Y. F. Yu and X. C. Li, Label-free detection with micro-opto-fluidic systems (MOFS): A review, Anal. . 391, 2443–2452 (2008). [2] Y. Yang, A. Q. Liu, L. Lei, L. K. Chin, C. D. Ohl, Q. J. Wang, and H. S. Yoon, A tunable 3D optofluidic waveguide dye laser via two centrifugal Dean flow streams, 11, 3182–3187 (2011). [3] Y. Yang, A. Q. Liu, L. K. Chin, X. M. Zhang, D. P. Tsai, C. L. Lin, C. Lu, G. P. Wang, N. I. Zheludev, Optofluidic waveguide as a transformation optics device for lightwave bending and manipulation, . 3, 651 (2012). [4] W. M. Zhu, A. Q. Liu, X. M. Zhang, D. P. Tsai, T. Bourouina, J. H. Teng, X. H. Zhang, H. C. Guo, H. Tanoto, T. Mei, G. Q. Lo and D. L. Kwong, "Switchable magnetic metamaterials using micromachining processes," Advanced Materials, Vol 23, Issue 15, 2011. [5] Y. H. Fu, A. Q. Liu, W. M. Zhu, X. M. Zhang, D. P. Tsai, J. B. Zhang, T. Mei, J. F. Tao, H. C. Guo, X. H. Zhang, J. H. Teng, N. I. Zheludev, G. Q. Lo, and D. L. Kwong, "A micromachined reconfigurable metamaterials via reconfiguration of asymmetric split-ring resonators," Advanced Functional Materials, Vol 21, Issue 18, 2011. [6] W. M. Zhu, A. Q. Liu, T. Bourouina, D. P. Tsai, J. H. Teng, X. H. Zhang, G. Q. Lo, D. L. Kwong and N. I. Zheludev, "Microelectromechanical maltese-cross metamaterial with tunable terahertz anisotropy," Nature Communications, Vol 3, 1274, 2012. [7] W. M. Zhu, Q. H. Song, L. B. Yan, W. Zhang, P. C.Wu, L. K. Chin, H. Cai, D. P. Tsai, Z. X. Shen, T. W. Deng, S. K. Ting, Y. D. Gu, G. Q. Lo, D. L. Kwong, Z. C. Yang, R. Huang, A. Q. Liu and N. Zheludev, "A flat lens with tunable phase gradient by using random access reconfigurable metamaterial," Advanced Materials, Vol. 27, pp. 4739-4743, 2015.
53 Invited talk
Dr. Eric Plum
University of Southampton, UK
March 23, 2016 Reconfigurable Nanomembrane Metadevices 09:40-10:10 2nd Conference Room (3F)
Biography for Eric Plum
Dr Eric Plum’s research interests include dynamic control of metamaterial functionalities and chirality. He is a Research Lecturer at the Centre for Photonic Metamaterials and the Optoelectronics Research Centre, University of Southampton, UK. After studies at RWTH Aachen (Germany), University of Southampton (UK) and as a Fulbright Scholar at New Mexico Tech (USA), Dr. Plum joined metamaterials research in 2006. His contributions to metamaterials have been recognized by the IoP QEP Thesis Prize, the Marconi Society Young Scholar Award and a Leverhulme Fellowship.
54 IN-8
Reconfigurable Nanomembrane Metadevices
Eric Plum1, João Valente1, Jun-Yu Ou1, Pablo Cencillo-Abad1, Artemios Karvounis1, Kevin F. MacDonald1 and Nikolay I. Zheludev1,2 S & E F U U U "&"&'
Abstract: Dynamic control over metamaterial optical properties enables active metadevices. Here we demonstrate optically, magnetically and electrically actuated metadevices providing functionalities from giant nonlinear and magneto-electro-optical effects to on- demand gratings, phase gradient surfaces, beam steering and focusing of light.
The broad range of enhanced and novel functionalities that conventional metamaterials can provide are usually not only resonant and therefore narrow-band, but also fixed. Dynamic control over metamaterial functionalities enables much more flexible active metadevices and is possible through coherent optical control over the light-matter interaction, phase transitions of constituent materials and M as discussed here M actuation of metamaterials on the nanoscale. Metamaterials and metasurfaces are arrays of coupled resonators and therefore their optical properties are sensitive to rearrangement of their building blocks on the nanoscale. Such actuation of thousands of metamolecules is enabled by dielectric nanomembranes, which are strong enough to support metamaterial nanostructures, yet flexible enough to allow their actuation by thermal, electrostatic, magnetic and optical forces M so far with up to 50% optical contrast and at modulation frequencies from kHz to 100s of MHz. We show experimentally that optical actuation of plasmonic and dielectric nanomembrane metamaterials gives rise to an exceptionally large optical nonlinearity [1, 2]. We demonstrate experimentally that nanomembrane metamaterials can be actuated by the magnetic Lorentz force acting on electrical charges moving in a magnetic field, and that this gives rise to a novel, giant magneto-electro-optical effect [3, 4]. Furthermore, we report on the development of first random access reconfigurable metamaterials, where the optical properties of the metamaterial nanostructure can be controlled with sub-wavelength resolution in one spatial dimension. We show numerically that such metadevices enable on-demand gratings, phase gradient surfaces, beam steering and focusing of light. In summary, reconfigurable metamaterial nanostructures allow the realization of active metadevices providing the optical properties that we want, where we want and when we want.
[1] J. Y. Ou, E. Plum, J. Zhang, and N. I. Zheludev, arXiv.org, 1506.05852 (2015). [2] A. Karvounis, J. Y. Ou, K. F. MacDonald, and N. I. Zheludev, arXiv.org, 1508.00995 (2015). [3] J. Valente, J. Y. Ou, E. Plum, I. J. Youngs, and N. I. Zheludev, Appl. Phys. Lett. 106, 111905 (2015). [4] J. Valente, J. Y. Ou, E. Plum, I. J. Youngs, and N. I. Zheludev, Nat. Commun. 6, 7021 (2015).
JV would like to thank the Defence Science and Technology Laboratory (DSTL) for their support (grant DSTLX1000064081).
55
Session: WED-IC-S2
Date: March 23 (Wednesday) Time: 10:30-12:00 Session Chair: 7 8 . % ` 7 % ? ? Room: WED-IC-S2 Invited talk
Prof. Uriel Levy
The Hebrew University of Jerusalem, Israel
Light-matter interactions in nanophotonics March 23, 2016 10:30-11:00 systems International Conference Hall (4F)
Biography for Uriel Levy
Prof. Uriel Levy joined the applied physics department of the Hebrew university in 2006, where he is a currently faculty member and the director of the Harvey M. Krueger Family Center for Nanoscience and Nanotechnology. His major research interests are nanophotonics, silicon photonics, plasmonic devices and nanoscale light vapor interactions. He has authored some 100 journal papers and over 200 conference presentations. He is the recipient of various prestigious prizes, including the Ben Porath prize for the outstanding young researcher at the Hebrew University. He is also a fellow of the OSA.
58 IN-9
Light-matter interactions in nanophotonics systems
Liron Stern, Meir Grajower, Jonathan Bar David, Alex Naiman, Roy Zektzer, Noa Mazurski, and Uriel Levy Department of Applied Physics, The Benin School of Engineering, The Center for Nanoscience and Nanotechnology, The Hebrew University of Jerusalem, Jerusalem 91904, Israel. [email protected] Abstract: \ " '
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59 Oral-1
Second Harmonic Generation in Reflective Gradient Metasurfaces
Kuang-Yu Yang, Jérémy Butet, and Olivier J. F. Martin Nanophotonics and Metrology Laboratory (NAM), Swiss Federal Institute of Technology Lausanne (EPFL), 1015, Lausanne, Switzerland E-mail address: [email protected]
Abstract: Generally, second harmonic (SH) emission from a localized surface plasmon mode suffers from the SH silencing effect due to the symmetry. To overcome this, we study the SH enhancement of a unique hybrid localized-propagating plasmonic mode supported by a reflective gradient metasurface. With the appropriate fundamental excitation, the anomalous reflection channel can be tailored into a hybrid plasmonic wave propagating along the metallic backplate. The strongly enhanced fundamental absorption results in a nearly 1800-fold enhancement of the SH intensity, compared to the normal incidence case.
Plasmonic metasurfaces, which can continuously control the phase and amplitude of electromagnetic waves via plasmonic nanostructures, have recently gained significant interest [1]. These metasurfaces provide extraordinary light manipulation capabilities along the propagation direction in spite of their subwavelength thickness in that direction. The various localized surface plasmon (LSP) modes supported by these nanostructures with different physical geometries enable local engineering of the optical properties along an ultrathin 2D array. Recently, facilitated by the high field enhancement and the rich symmetry properties of the LSP modes, several fascinating works have demonstrated light manipulation not only for linear but also for nonlinear signals using nonlinear metasurfaces [2]. In this work, we combine both surface integral equation (SIE) simulations and experiments to study the mechanisms of second harmonic generation (SHG) of a reflected gradient metasurface constructed with silver nanostructures and an optically-thick backplate spaced by a 30 nm SiO2 spacer, Fig. 1(a) [3]. The gradient metasurface is designed and optimized to support an anomalous reflection channel at 800 nm for TM- polarized incidence. Interestingly, at a specific incident angle slightly larger than the one turning the anomalous beam into an evanescent beam, a plasmonic hybrid mode resulting from the interaction of localized and propagating plasmons is observed, Fig. 1(b). Furthermore, the excited hybrid mode results in a strong absorption at the fundamental wavelength, thus producing a maximum SH intensity, Fig. 1(c). The SH intensity is enhanced around 1800 times compared to the normal incident case. To understand the mechanisms of SH enhancement for this hybrid plasmon mode, we compare two cases in the simulation, with the nonlinear susceptibility being applied either on the nanoantenna (case I) or on the silver mirror (case II). A pronounced SH enhancement appears in the case II when the incident angle is such that the hybrid plasmon mode is excited at the fundamental, Fig. 1(d). This indicates that the strong SH enhancement for the hybrid plasmon mode originates from its absorption enhancement counterpart at the fundamental wavelength.
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[1] S. Sun, K.-Y. Yang, C.-M. Wang, T.-K. Juan, W. T. Chen, C. Y. Liao, Q. He, S. Xiao, W.-T. Kung, G.-Y. Guo, L. Zhou, and D. P. Tsai, Nano Lett. 12, 6223-6229 (2012). [2] G. Li, S. Chen, N. Pholchai, B. Reineke, P. W. H. Wong, E. Y. B. Pun, K. W. Cheah, T. Zentgraf, and S. Zhang, Nat. Mater. 14, 607M612 (2015). [3] J. Butet, B. Gallinet, K. Thyagarajan, and O. J. F. Martin, J. Opt. Soc. Am. B 30, 2970-2979 (2013).
60 Oral-4
Millimeter-sized ultra-smooth single-crystalline gold flakes for large-area plasmonic and metasurfaces applications
You-Xin Huang (湫⎛㖽), Kel-Meng See (⼸↙㖶), Jer-Shing Huang (湫⒚⊛) U C C " " U ' "
Abstract: Single-crystalline gold flakes is indispensable for fabricating well-defined nanostructures but the current method can only produce multi-crystalline gold flakes with large area or single-crystalline one with limited area. Here we present a method for synthesizing single-crystalline gold flakes with millimeter-sized area which can serve as nice substrate for fabricating plasmonic nanostructures and metasurfaces.
1. Introduction Electron beam lithography (EBL) and focused-ion beam (FIB) milling are the common methods for fabrication designed nanostructures. For both fabrication methods, well-known thermal evaporation and sputtering process are commonly used to prepare the metallic substrate. However, so-prepared films are multi- crystalline in nature and the grain boundaries and bumpy surface can lead to serious scattering and loss of the surface plasmon polaritons, which greatly limit the performance of the real nanodevices. In order to resolve the problems due to random grains, self-assembled single-crystalline gold flakes have been used as metallic substrate for the fabrication of high-definition nanostructures [1]. Currently, the size of the self-assembled gold flakes is limited to micrometer size [2]. Since the area determines the number of nanostructures and the size of the plasmonic nanocircuits can be fabricated, it is of great demand to increase the size of the single- crystalline gold flakes. In this work, we present a method to synthesize world-recorded ultra-large millimeter-sized single crystalline gold flakes. Gold is chemically stable, biocompatible and suitable for SPR in the red to near- infrared spectral regime. Our work has made progress on the study of plasmonic nanostructure. 2. Experimental Results Our method is based on the polyols method which can produce micron-sized gold flakes [3]. This method uses ethylene glycol to reduce the gold precursors to gold nanoparticles. Briefly, 5 mL of pure ethylene glycol, 0.027 mmol of hydrogen tetrachloroaurate trihydrate (HAuCl4炽3H2O) and 0.012 mmol of sodium chloride (NaCl) are added into a glass bottle containing 180 )L of water. A few cleaned coverslips are placed inside the container to serve as a support for the gold flakes to grow. After stirring the bottle is put into an oven to keep the reaction at constant temperature of 95 °C for five days. This procedure can effectively produce gold flakes with micrometer to millimeter size.
Fig. 1. The SEM (left) and real (right) image of millimeter-sized gold flakes.
3. Reference [1] Huang, J.-S.; Callegari, V.; Geisler, P.; Brüning, C.; Kern, J.; Prangsma, J. C.; Wu, X.; Feichtner, T.; Ziegler, J.; Weinmann, P.; Kamp, M.; Forchel, A.; Biagioni, P.; Sennhauser, U.; Hecht, B., Atomically flat single-crystalline gold nanostructures for plasmonic nanocircuitry. Nat. Commun. 2010, 1, 150. [2] Guo, Z.; Zhang, Y.; DuanMu, Y.; Xu, L.; Xie, S.; Gu, N., Facile synthesis of micrometer-sized gold nanoplates through an aniline-assisted route in ethylene glycol solution. Colloids and Surfaces A: Physicochemical and Engineering Aspects 2006, 278 (1M3), 33-38. [3] Li, C. C.; Cai, W. P.; Cao, B. Q.; Sun, F. Q.; Li, Y.; Kan, Y. X.; Zhang, L. D., Mass Synthesis of Large, Single-Crystal Au Nanosheets Based on a Polyol Process. Adv. Funct. Mater. 2006, 16 (1), 83-90.
61 Oral-7
Practical and High Efficient Radial Coupling Plasmonic Probe Design for Near Field Application
Ruei Han Jiang(㰇⎉㵝)1, Jen-Yu Chu(㛙ṩỹ)2,Ta-Jen Yen(♜⣏ả)1 U C F A S C " " U US S
Abstract: In this work, we designed a novel scheme for apertureless plasmonic probes under internally radial illumination. Employing non-periodic multi-rings geometry for plasmonic excitations, surface plasmon polariton (SPP) adiabatically nanofocuses energy at tip and the full width at half maximum of the optimal design is ~18 nm. The proposed probe was optimized with 2D finite-difference time-domain (FDTD) analysis and realistic isotropic etching dielectric AFM probe geometries. Comprehensive electromagnetic simulation shows that the optimal probe feature obeys FabryMPérot condition on the lateral metallic wall. Thanks to radial symmetry efficient matching between conical probe and radial illumination, the optimal probe gives over 6 orders of magnitude larger field enhancement than conventional aperture probe without degrading its spatial resolution. Finally, the proposed tip is applied in the near field application to resolve the interference of surface wave.
keywordsǺNSOM, SPP, FabryMPérot condition, nanofocusing, apertreless probe
1. Optimal plasmonic near field probe design Our idea is to open a slit on the side of the gold deposition on the sharp probes with curved surface, which can be fabricated by isotropic wet-chemical etching process, since we envision a probe design with curved shape, the metal slits were realized by FIB milling process, as shown in inset Fig1. (b) For simplicity, we optimized the radius of rings from inner to outer rings in order with increasing rings under 632nm radial illumination, as shown in the Fig1. (b), by 2D FDTD calculation. Each ring was optimized for the position of the curved surface with 100 nm gap width to get strongest local field at tip apex. In Fig 1(a), when increasing the ring number, the field enhancement factor is increasing and saturated ? R number excited more SPP wave. However, SPP wave is dissipated after propagating longer length. As a result, the propagation length of SPP and rings number are tradeoff parameter. Further on, we applied the optimal dimension of the proposed dimension into the 3D FDTD simulation and simulated the E field distribution as shown in Fig.1 (a) separately. By observing Fig.1 (b), the optimal multi-rings structures under radial illumination efficiently supported SPP excitation and the propagation length is corresponding constructively interference for SPP wave with radial symmetry propagating along surface to the apex. The proposed tip can achieve much higher field intensity enhancement than previous works [1, 2]. Finally, the proposed probe further can succeed to detect the near field of nano hole array structure, as shown in Fig1. (c), and resolve interference of surface wave in near field. 2. Figures
2 Fig. 1. The proposed plasmonic probe (a) Enhancement factor (EF) = (E/E0) ,where E0 is electrical field of 632nm radial illumination, and Enhanced efficiency = (EF#/EF#-1) for adding 1 ring in order are in left and right axis separately. When adding 7rd rings, the enhanced efficiency is saturated to 1. As a result, the optimal number is 6 rings. After 3D FDTD simulation, (b) absolute value of E field normalized by E0 as shown here. The dielectric AFM probe with sputter 2nm chrome and 120nm gold deposition and etched ring structure by FIB with 7.7 pA is shown in inset (b) SEM image of the proposed probe. (c) NSOM measurement of nano hole array whose periodic is 600nm and diameter of hole is 100nm on the 100 nm gold film by the proposed probe. 3. Reference [1] Y. Wang, Y.-Y. Huang, and X. Zhang, "Plasmonic nanograting tip design for high power throughput near- field scanning aperture probe," vol. 18, pp. 14004-14011, 2010/06/21 2010. [2] S. Cherukulappurath, T. W. Johnson, N. C. Lindquist, and S.-H. Oh, "Template-Stripped Asymmetric Metallic Pyramids for Tunable Plasmonic Nanofocusing," vol. 13, pp. 5635-5641, 2013/11/13 2013.
62 Session: WED-R1-S2
Date: March 23 (Wednesday) Time: 10:30-12:00 Session Chair: = @. ` 0 ` @ 0 7 % 1 1 @ @@ 0 7 ] ] Room: 1st Conference Room (3F) WED-R1-S2 Invited talk
Dr. Fan Wang
Macquarie University, Australia
Advanced Optical Microscopy enabled single March 23, 2016 10:30-11:00 nanoparticle characterization and its applications 1st Conference Room (3F)
Biography for Fan Wang
Dr. Wang obtained his Ph.D. from University of New South Wales, Australia in 2013 for his studies exploring optical properties of single nanoparticles utilizing novel photoluminescence optical tweezers. From 2013 to 2015, Dr. Wang worked as a Research Fellow at the Australia National University under the supervision of Prof. Jagadish. At this position, Dr. Wang mentored three optical labs, where he developed several optical systems including Micro-Raman/ Photoluminescence (PL) system, low temperature time resolved PL system, and Fourier domain PL imaging system to investigate novel materials such as nanowire, nanowire laser and 2D materials. Since 2015, Dr. Wang has been part of the Australian Research Council (ARC) center of excellence for nanoscale biophotonics (CNBP) at Macquarie University node as a Research Fellow. In his current role, Dr. Wang has focused on using scanning confocal micro-system to research the optical properties of single up-conversion nanoparticles (UCNP) and developing super-resolution imaging method. As a visiting research fellow, Dr. Wang has also been involved with the initiative for Biomedical Materials & Devices (IBMD) at the University of Technology, Sydney, where he is mentoring and developing three optical labs. Currently, Dr. Wang’s area of emphasis has been biophotonics application through combining optical tweezers with UCNP.
64 IN-10
Advanced Optical Microscopy enabled single nanoparticle characterization and its applications
F.Wang1,2 1 Advanced Cytometry Labs, ARC Centre of Excellence for Nanoscale BioPhotonics (CNBP), Faculty of Science, Macquarie University, Sydney, NSW 2109, Australia 2Institute for Biomedical Materials & Devices (IBMD), Faculty of Science, University of technology, Sydney, Sydney, NSW 2007, Australia E-mail address: [email protected]
Abstract: We review our research findings on using novel optical methods including photoluminescence optical tweezers (POT), micro-time resolved photoluminescence (3TRPL) and Fourier domain PL imaging to characterize single nanoparticle, such as semiconductor nanowire, two-dimensional (2D) materials and gold nanoparticles.
1. Introduction Benefiting from great advancement in the field of material science, many novel advanced low dimensional materials have been well developed, especially for nanoparticles and 2D materials. Based on their unique optical and electric properties, those advanced materials have been widely used in nanophotoncis, bio-imaging and sensing, solar cell, detector and laser. However, suffering from their smaller dimensions, a single nanoparticle is difficult to be manipulated and characterized by traditional optical technologies, which also limits the application of single nanoparticles. In this paper, we will review using advanced optical methods to manipulate and characterize novel low dimensional materials. 2. Results and Discussion We have been applying POT to investigate the optical property and trapping of single nanoparticles. Applying spatial light modulator, we have developed a novel in-situ method to experimentally measure the axial stability trapping points and map the axial trapping dynamics for dual spots trapping of single semiconductor nanowires [1]. We also have used POT to ! # $ # % & ' With 3TRPL system, we have developed a pure optical method to evaluate the internal quantum efficiency, non-radiative lifetime and doping concentration of photonics devices [5]. Utilizing the Fourier domain PL imaging, the lasing mode property of single semiconductor laser has been well studied [6]. Combining multi-optical methods including ( # # # & # # ) * + 3. Acknowledgements I would like to sincerely thank Dr. P.J. Reece (UNSW), Prof. H.H. Tan and Prof. C. Jagadish (ANU), Prof. D. Jin (UTS) for their fruitful scientific collaboration, discussions and mentoring. I also thank the Australian Research Council for the financial support of this research. Australian National Fabrication Facility is acknowledged for the access to the nanowire growth facilities used in this work. 4. References [1] F. Wang, W. J. Toe, W. M. Lee, D. McGloin, Q. Gao, H. H. Tan, et al., "Resolving Stable Axial Trapping Points of Nanowires in an Optical Tweezers Using Photoluminescence Mapping," Nano Letters, vol. 13, pp. 1185-1191, 2013/03/13 2013. [2] F. Wang, P. J. Reece, S. Paiman, Q. Gao, H. H. Tan, and C. Jagadish, "Nonlinear Optical Processes in Optically Trapped InP Nanowires," Nano Letters, vol. 11, pp. 4149-4153, 2011/10/12 2011. [3] K. Pearce, F. Wang, and P. J. Reece, "Dark-field optical tweezers for nanometrology of metallic nanoparticles," Opt. Express, vol. 19, pp. 25559-25569, 2011. [4] A. Andres-Arroyo, F. Wang, W. J. Toe, and P. Reece, "Intrinsic heating in optically trapped Au nanoparticles measured by dark-field spectroscopy," Biomedical Optics Express, vol. 6, pp. 3646-3654, 2015/09/01 2015. [5] F. Wang, Q. Gao, K. Peng, Z. Li, Z. Li, Y. Guo, et al., "Spatially Resolved Doping Concentration and Nonradiative Lifetime Profiles in Single Si-Doped InP Nanowires Using Photoluminescence Mapping," Nano Letters, 2015/04/01 2015. [6] D. Saxena, F. Wang, Q. Gao, S. Mokkapati, H. H. Tan, and C. Jagadish, "Mode Profiling of Semiconductor Nanowire Lasers," Nano Letters, vol. 15, pp. 5342-5348, 2015/08/12 2015. [7] J. Yang, Z. Wang, F. Wang, R. Xu, J. Tao, S. Zhang, Q. Qing, B.L. Davides, C. Jagasiah, Z. Yu and *Yuerui Lu, “Atomically Thin Optical Lenses and Gratings”, Light Science & Applications, accepted 2015.
65 Oral-2
Superresolution using Dielectric Microspheres
Pin-Yi Li1,2*, Yang Tsao1,2, Yun-Ju Liu2, Shi-Wei Chu2, Chih-Wei Chang1, U U "&
Abstract: Various superresolution techniques have been developed to achieve spatial resolution beyond diffraction limit. However, those techniques encounter difficulties, such as slow scanning speeds, short-lived fluorescent dyes, or complex fabrication processes. Recently, researchers found that dielectric microspheres could bring the sub-wavelength information to far field, achieving superresolution with a much simpler method [1]. Yet the underlying mechanism is still unknown. In this work, we will unravel many unusual imaging properties of microspheres.
Semi-immersed microspheres coated with polymethyl methacrylate (PMMA) are found to reach ( & spatial resolution for sapphire microspheres and (" for glass microspheres. Moreover, we also find that the resolution of microsphere is dependent on the diameter of microspheres, as showed in Fig. 1. To investigate the underlying mechanism, we have developed a method to transfer microsphere microlens via a PMMA film (as showed in Fig. 1.), which enables us to study the resolution when gradually lifting up the microsphere above a sample. Interestingly, we found the defocused images agree with the theory of a conventional lens rather than evanescent waves. Alternatively, whispering gallery mode (WGM) [3, 4] is also proposed to explain the superresolution. However, by continuously tuning the incident wavelength or the temperature of the microsphere, we exclude that the WGM is unlikely the mechanism. Nevertheless, strong polarization dependent resolution is also found when imaging blu-ray DVD, which suggests that surface plasmon plays an important role in achieving superresolution. Curiously, we find that high index barium titanate glass (BTG) microspheres [5] exhibit different characteristics from those of other types of microspheres. These results show that the imaging properties of dielectric microspheres are very unusual.
(a) (c)
Fig. 1. (a) Blu-ray DVD imaged by a microsphere with a diameter of 11.3 )m. (b, c) Lateral view of the microspheres coated with PMMA (the thickness is about 4)m).
[1] Z. Wang, W. Guo, L. Li, B. Luk'yanchuk, A. Khan, Z. Liu, Z. Chen, and M. Hong. "Optical virtual imaging at 50 nm lateral resolution with a white-light nanoscope.", Nature communications, 2, 218 (2011). [2] C. J.R. Sheppard, “ Fundamentals of superresolution”, Micron, 38, 165-169 (2007) [3] A. Heifetz, S. C. Kong, A. V. Sahakian, A. Taflove, and V. Backman. "Photonic nanojets." J. Comput. Theor. Nanosci. 9, 6 (2009). [4] Y. Duan, G. Barbastathis, and B. Zhang, “Classical imaging theory of a microlens with super-resolution.”, Optt. Lett., 38, 16 (2013). [5] A. Darafsheh, G. F. Walsh, L. D. Negro, and V. N. Astraov, ĀOptical super-resolution by high-index liquid-immersed microspheres.” Appl. Phys. Lett. 101, 141128, (2012)
66 Oral-5
! " ! #$%$&$ ' + #$%$ B U U & U U U $ U " U U U "( (
" / Light induced fluorescent microscopy has long been developed to observe and understand the object at microscale, such as cellular sample. However, the transfer function of lens-based imaging system limits the resolution so that the fine and detailed structure of sample cannot be identified clearly. The techniques of resolution enhancement are fascinated to break the limit of resolution for objective given. In the past decades, the resolution enhancement imaging has been investigated through a variety of strategies, including photoactivated localization microscopy (PALM), stochastic optical reconstruction microscopy (STORM), stimulated emission depletion (STED), and structure illuminated microscopy (SIM) [1]. In those methods, only SIM can intrinsically improve the resolution limit for a system without taking the structure properties of object into account. In this paper, we develop an algorithm for SIM-based system associated with Bayesian estimation as shown in Fig.1 [2], furthermore, with optical sectioning capability rendered from HiLo processing [3], resulting in high resolution through 3D volume. Our proposed 3D microscopic imaging can provide optical sectioning with resolution enhanced performance, and be robust to noise owing to the Data driven Bayesian estimation reconstruction. For validating the 3D SIM, we show our simulation and experimental results of algorithm to demonstrate the 3D resolution enhancement.
Fig.1 (a-c) is the simulated image based on the conventional microscopy, regular SIM and BI- SIM, respectively. (d) The intensity profile plotted along the red line.
; < / [1] Daniel Evanko, "Primer: fluorescence imaging under the diffraction limit," Nature Methods =, 19 - 20 (2009). [2] ` 1 } ~T D } } " ~ ~ and Guy M. Hagen, "Three-dimensional super-resolution structured illumination microscopy with maximum a posteriori probability image estimation," Opt. Express %%, 29805-29817 (2014). [3] 1 ~ ~ 2 -field fluorescence sectioning with hybrid speckle and uniform illumination 1 ? M1821 (2008).
67 Oral-8
> @ @ ! ' + #$%$ + %$ $ % ' + %$[ B U U & U U U $ U S " U U $ U S U U U ( &
\ !] / Optical sectioning, , fluorescence microscopy
Wide field fluorescent microscopy is implemented with a digital micro-mirror device (DMD) to create a structured illumination pattern onto tissue sample. The orientation and spatial frequency of the grid pattern is adjusted by the DMD to obtain an optimum contrast of the modulated pattern. The optical sectioning capability of a structured microscope is provided by the pattern of excitation light modulated by a DMD. In order to monitor Canenorhabditis elegans, the optically sectioned image is obtained at a fast vedio rate by switching the structured pattern on and off due to the fast frame rate of the DMD. A focus tunable lens is placed at the center plane of the system to conduct an axial scanning without mechanical scanning to move the structured illumination pattern across the sample at a constant magnification. The position of the focus-tunable lens and the imaging performance of the system are analyzed and discussed through the model in ZEMAX. The optical design of the fluorescent microscope with DMD and focus tunable lens is characterized and analyzed. Furthermore, Optically sectioned 3D images can be acquired without scanning in real time.
Figure 1. Fluorescent images of a C. elegans (a) structured illumination, (b) uniform illumination images.
; < / [1] Y. Luo, V. R. Singh, D. Bhattacharya, E. Y. S. Yew, J.-C. Tsai, S.-L. Yu, H.-H. Chen, J.-M. Wong, P. ` 2 ` ` 1 0 } ^_`q$ L71 (2014).
68 Session: WED-R2-S2
Date: March 23 (Wednesday) Time: 10:30-12:00 Session Chair: Eric Plum (University of Southampton, UK) R . . ` ? 1 0 7 ? 1 Room: 2nd Conference Room (3F) WED-R2-S2 Invited talk
Prof. Ann Roberts
The University of Melbourne, Australia
Metasurfaces as spatial filters for optical March 23, 2016 10:30-11:00 information processing 2nd Conference Room (3F)
Biography for Ann Roberts
Ann Roberts obtained B.Sc. (Hons) and Ph.D. degrees from the University of Sydney and is now a Professor in the School of Physics at the University of Melbourne. She has diverse research expertise in the fields of physical optics and photonics. In particular, Professor Roberts has had a career-long interest in the interaction of light with subwavelength structures and has made recent significant advances in the computational and experimental study of plasmonic devices, metamaterials and nanoscale antennas. Prof Roberts' research interests also include the development of novel microscopic and imaging techniques and their application to the non- destructive examination of specimens such as cells, photonic devices and cultural materials. She is a Fellow of the Australian Institute of Physics, a Senior Member of the Optical Society of America and immediate Past President of the Australian Optical Society.
70 IN-11
Metasurfaces as spatial filters for optical information processing
Ann Roberts School of Physics, The University of Melbourne, 3010 Australia E-mail address: [email protected]
Abstract: Metasurfaces are artificially fabricated, ultrathin films that exhibit a tailored response to incident electromagnetic radiation. Here theoretical, computational and experimental progress toward the design and demonstration of phase and polarization- sensitive metasurfaces for applications in optical image processing will be presented.
1. Introduction The properties of optical wavefields, such as polarization and phase, can be utilised in applications ranging from information processing, communications and imaging. Nanoscale antenna elements can be tailored to have a characteristic response to these properties providing an avenue for the development of ultracompact devices that will perform on-chip, real-time, single-shot conversion of wavefield information to readily measured intensity maps. 2. Dark modes Metasurfaces consist of arrays of subwavelength nanostructures that exhibit characteristic resonances. While attention has been focused on taking advantage of the lowest order electric dipole mode, resonators exhibit a range of higher order modes. While the dipole mode can be easily excited with a normally incident plane wave, many modes are ‘dark’ or ‘subradiant’ precluding their excitation with a uniform field. Such modes can, however, be excited with fields possessing non-uniform polarization [1] or phase [2] distributions, suggesting an avenue for converting optical information carried in the form of phase or polarisation into variations in the intensity of a wavefield that can be detected using conventional camera technology.
Fig. 1. Plane wave transmission through a square array (period d) of annular apertures in a perfectly conducting film of thickness 2.7d as a function of normalised wavevector. The outer and inner radii of the apertures are 0.375d and 0.333d respectively. The figure on the left
is at a wavelength of 2.22d (TE11 coaxial waveguide mode resonance), while on right the wavelength is 2.78d, a TEM mode resonance. 3. Optical information processing and imaging The sensitivity of metasurfaces utilizing dark modes to map phase gradients in a wavefield can be characterized by determining the reflection from or transmission through a metasurface as a function of angle of incidence to give the optical transfer function. This provides insight into the potential for using metasurfaces in optical image processing operations such as edge detection and phase imaging. As an example, Fig. 1 shows the computed transmission of x-polarised plane waves through an array of coaxial apertures in a PEC film when either the dipole TE11 mode (a) or the radial TEM coaxial waveguide mode (b) is excited. The high fidelity of the transmission of spatial frequency information by the dipole mode is apparent, as is the enhancement in high- spatial frequency information along the direction of polarisation when the TEM mode is on resonance. 4. References [1] D.E. Gómez, Z.Q. Teo, M. Altissimo, T. J. Davis, S. Earl, and A. Roberts, Nano Lett. 13, 3722-3728 (2013) [2] A. Roberts, Opt. Lett., 18, 2528-2533 (2010) [3] F. Eftekhari, D.E. Gómez and T.J. Davis, Opt. Lett. 39, 2994-2997 (2014)
71 Oral-3
Silicon-Based Metalens with Zero Refractive Index Xin-Tao He and Jian-Wen Dong B $ &$ Abstract: \ the Snell’s law was quantitatively consistent with those fro #
& # # # ' *_= ' *`#= {# #_{_ % " _ # # " _ # _^ # effective refractive index retrieved from the Snell’s law w ' # % # #
" _ {# #_{_ % # _^ References *_= X. Huang, Y. Lai, Z. H. Hang, H. Zheng, and C. T. Chan, “Dirac cones induce # #index materials”, Nat. Mater. 10, 582 (2011) *`= P. Moitra, Y. Yang, Z. Anderson, I. I. Kravchenko, D. P. Briggs, and J. Valentine, “Realization of an all# # tamaterial”, Nat. Photon. 7, 791 (2013). *= & Lon6ar, , “ # # ”, Nat. Photon. 9, 738 (2015.) *^= # #Wen Dong, et. al, “Silicon#Based Metalens with Zero Refractive Index”, to be
72 Oral-6
Sorting Self-Assembled Single-Crystalline Gold Microplates by Eddy Current
Meng-Chi Chen, Jer-Shing Huang National Tsing Hua University E-mail address: [email protected]
Abstract: Time-variant magnetic flux can induce eddy current in metallic objects and thereby create induced magnetic dipoles that oppose the change of external magnetic field. Eddy current has been applied in centimeter- to meter-scale sorting of metallic objects[1]. Recently, we have chemically synthesized self-assembled gold microplates (AuMPs) with very large aspect ratio (surface area >103 ) 2 ) )[2]. In such kind of thin AuMPs, we have successfully induced significantly large eddy current using rotating permanent magnets (1400 rpm, 0.7 Tesla) and the effect of eddy current on the motion of plates is observable. We found that the AuMPs can be sorted in the moving direction of the magnets and the positions of the AuMPs are correlated to the distribution of the surface area. Such surface area dependent spatial distribution is due to the fact that AuMPs with larger surface area can support larger eddy currents and thus results in stronger magnetic force compared to the smaller AuMPs. As a result, larger flakes are brought farther by the rotating magnets than smaller ones. Our observation demonstrates that eddy current can be used to sort microplates in terms of their size, shape and material. In this work, we experimentally demonstrate the sorting, theoretically study the induced eddy currents and quantitatively estimate the eddy current force exerted on the AuMPs. In principle, all applications of eddy current, such as heating[3] and alignment[4], can also be implemented to such micrometer to nanometer scale systems. The induced eddy current and corresponding magnetic dipole offers unique opportunity for particle sorting and alignment as well as nanoscale heating.
1. Introduction to main text format and page layout Synthetic self-assembled gold plates usually exhibit broad size distribution and randomly distributed orientation, which limit the applications. We intend to apply eddy current for size sorting at the nanometer scale (Fig. 1 ). Although the current and the magnetic force become smaller when the area of the circulating current shrinks, such small force is expected to be sufficient for the very small conductive micro- and nanoparticles. For self-assembled thin gold plates, the aspect ratio is typically larger than 200, meaning that the flakes are very light but the induced current and resulted force can still be very large. Since eddy current is size- and shape-dependent, using eddy current for nanoparticle sorting and alignment can be an easy and cost-efficient alternative for the commonly used centrifugation. Other applications of eddy current, such as the heating in induction oven, might also be introduced at the nanoscale. We intend to use a rotor hemmed with permanent magnetic to induce eddy current on the self-assembled single-crystalline gold plates to sort them in terms of their effective area for eddy current(Fig. 2 ). When the magnets move toward the gold microplate (AuMP), eddy current is induced in the AuMP to create a field oppose to the changing magnetic field. Thus, it generate a repulsion force and the AuMP moves forward. The leaving AuMP generates an attraction force by the same principle[5]. 2. Figures and tables
Fig. 2 The working principle of this experiment. 4. References [1] Groothoff, J.A., Method for recycling aluminium slags comprising an eddy current separator operating at reduced rotary speed. 2009, Google Patents. [2] Huang, J.S., et al., Atomically flat single-crystalline gold nanostructures for plasmonic nanocircuitry. Nat Commun, 2010. 1: p. 150. [3] Dennis, C.L., et al., Nearly complete regression of tumors via collective behavior of magnetic nanoparticles in hyperthermia. Nanotechnology, 2009. 20(39). [4] Wang, M., et al., Magnetic tuning of plasmonic excitation of gold nanorods. J Am Chem Soc, 2013. 135(41): p. 15302-5. [5] Benson, H., University physics. Rev. ed. 1996, New York: John Wiley. xvi, 942, 47 p.
73 Oral-9
Tailor the functionalities of metasurfaces based on a complete phase diagram
Shaojie Ma, Lei Zhou* F F A "" 0
Abstract: Metasurfaces in metal/insulator/metal configuration have been widely used in photonics, with applications ranging from perfect absorption to phase modulation, but why and when such structures can realize what functionalities are not yet fully understood. Here, we establish a complete phase diagram in which the optical properties of such systems are fully controlled by two simple parameters (i.e., the intrinsic and radiation losses), which are in turn dictated by the geometrical/material properties of the underlying structures. Such a phase diagram can greatly facilitate the design of appropriate metasurfaces with tailored functionalities, demonstrated by our experiments and simulations in the Terahertz regime. In particular, our experiments show that, through appropriate structural/material tuning, the device can be switched across the phase boundaries yielding dramatic changes in optical responses. Our discoveries lay a solid basis for realizing functional and tunable photonic devices with such structures.
Fig. Phase diagrams of (I) the absorption A and (II) the span of reflection phase on-resonance versus R and R , calculated with CMT for the single-port model. (a) R factors and (b) Phase diagrams of R factors for a series of metasurfaces with varying spacer thickness . (c) reflectance and (d) reflection phase of four typical samples
Reference [1] S. Fan, W. Suh, J. D. Joannopoulos, J. Opt. Soc. Am. A 20, 569 (2003). [2] S. Ma, S. Xiao, L. Zhou, Phys. Rev. B, received. [3] C. Qu, S. Ma, et. al. Phys. Rev. L 115, 235503 (2015).
74 Session: WED-IC-S3
Date: March 23 (Wednesday) Time: 13:30-15:00 Session Chair: % 7 7 ; R . ` . ? 0 7 ? 1 Room: WED-IC-S3 Invited talk
Prof. Olivier J.F. Martin
Swiss Federal Institute of Technology Lausanne (EPFL), Switzerland
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Using the modal structure of plasmonic systems March 23, 2016 to boost their efficiency in the linear and non- 13:30-14:00 linear regimes International Conference Hall (4F)
Biography for Olivier J.F. Martin
Olivier J.F. Martin is Professor of Nanophotonics and Optical Signal Processing at the Swiss Federal Institute of Technology, Lausanne (EPFL), where he is head of the Nanophotonics and Metrology Laboratory and Director of the Doctoral Program in Photonics. His research interests focus on the interactions of electromagnetic fields with low dimension systems, especially in the optical regime and with emphasis on plasmonics. Dr. Martin has authored above 200 journal articles and holds a handful of patents and invention disclosures.
76 IN-12
Using the modal structure of plasmonic systems to boost their efficiency in the linear and non-linear regimes
G.D. Bernasconi, J. Butet, K.-Y. Yang, C. Yan, and O.J.F. Martin A U A
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77 Oral-10
Manganese-doped Near-infrared Emitting Nanocrystals for in vivo Biomedical Imaging
Wing-Cheung Lawa,b*, Nanxi Raoa, Tai-Lok Cheunga, Ken-Tye Yongc, Xin Liud aDepartment of Industrial and Systems Engineering, The Hong Kong Polytechnic University, Hung Hom, Kowloon, Hong Kong, P.R. China bInstitute for Lasers, Photonics, and Biophotonics, University at Buffalo, Buffalo, New York, USA cSchool of Electrical and Electronic Engineering, Nanyang Technological University, Singapore 639798, Singapore E Ink Corporation, Fremont, California, USA;. *E-mail address: [email protected] Abstract: # % ¡ ' ¢ # ' £ ' ¤_^¥ " ¦ %
78 Oral-13
Evanescent fields Assisted in Symmetry-Breaking of Gold Nanoantenans
Jhen-Hong Yang, Kuo-Ping Chen* U " B " S U U
Abstract: Symmetry-breaking and scattering cancelation have been observed in dark-mode resonance of dipolar gold nanoantennas coupled by oblique incidence and total internal reflection. However, the coupling efficiency could be twice stronger when the incidence angle is larger than the critical angle. Hamiltonian equation and extinction spectra are used to analyze the hybridization model of symmetry dipolar gold nanoantennas. The antibonding mode could be coupled successfully by both TM and TE polarization.
1. Introduction For identical nanoparticle dimers, the resonance wavelength of different coupling modes will be changed to the corresponding phase of electric displacement field by TM and TE polarization fields in different oblique incidence angles. In the case of metallic nanoparticle dimers, the in-phase (out-of-phase) response of two dipoles is called the bonding (antibonding) mode or bright (dark) mode, resemble to molecular orbital theory [1,2]. The antibonding mode resonance of NAs can be predicted by the plasmonic Hamiltonian theory.
22 CSC 2 22 2 S2 122 2222 121 4() ( ) DT (1) 2212 EU
2. Result and discussion ^:_ ^G_ ^H_ :0VCVJ$ . ^JI_
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Fig. 1. Two-dimensional mapping extinction spectra with TM-polarize incidence light for incidence angles ranging from 0° to 89°and wavelengths ranging from 600 to 880 nm of (a), (d) TM transverse type antennas, (b), (e) TM longitudinal type antennas and (c), (f) TM type single particle. Red arrows indicate the direction of light.
Very interestingly, in Fig. 2(h), when incidence angle is larger than critical angle, the strong enhancement of coupling efficiency in antibonding mode has been shown. 3. Conclusion Hybridization model of plasmonic NAs and the coupling resonance wavelengths could be predicted by solving the plasmonic Hamiltonian equation. Different types of the coupling modes could be found when changing incidence angles. In addition, by comparing with the reflectance spectra, the enhancement of coupling efficiency to antibonding mode of NAs under the evanescent wave could be explained. The antibonding mode could apply to improve the sensitivity because of the high quality factor [3] and the slower radiative decay. 4. References [1] H. Wang, D. W. Brandl, P. Nordlander, and N. J. Halas, "Plasmonic nanostructures: artificial molecules," Accounts of chemical research 40, 53-62 (2007). [2] E. Prodan, C. Radloff, N. J. Halas, and P. Nordlander, "A hybridization model for the plasmon response of complex nanostructures," Science 302, 419-422 (2003). [3] Y.-H. Chen, K.-P. Chen, M.-H. Shih, and C.-Y. Chang, "Observation of the high-sensitivity plasmonic dipolar antibonding mode of gold nanoantennas in evanescent waves," Appl. Phys. Lett. 105, 031117 (2014).
79 Oral-16
Self-assembly with Langmuir-Blodgett method for gold nanodimer structures
Shiho IKEGAMI1, Nobuyuki TAKEYASU1, Takuo TANAKA2,3, Takashi KANETA1
Abstract: A part of surface of a gold nanoparticle was chemically modified with Langmuir- Blodgett method. The partially modified gold nanoparticles are self-assembled into dimer structures. We measured the extinction spectra of the gold dimer structures dispersed in ethanol.
1. Introduction Recently, significance of self-assembly has inceased in plasmonics to fabricate a large amount of metallic nanostructures. A wide variety of metallic nanoparticles (NPs), such as nanorods, nanoprisms, and nanostars, have been reported[1], and it is desired to fabricate larger and more complex structures exhibiting more sophisticated plasmonic functions by self-assembly where NPs are used as building blocks[2,3]. However, it is difficult to synthesize pairs of NPs, which are dimer structures, with self-assembling methods although a dimer is the simplest structure composed of plural NPs. Self-assembly of Au dimer structures has been reported where DNA origami is used as a platform to fix two AuNPs close each other[3]. The yeild of AuNP dimers is ~60%, and ~40% is other structures although it is a well-designed method for dimerization of AuNPs. A key point to increase the yield of dimer structures is avoiding unwanted bindings among NPs. In this report, we propose a novel assembling method for highly selective fabrication of AuNP dimer structures. The only binding site is introduced on the surface of each AuNP, which forces a AuNP to bind with only AuNP. A binding site at a AuNP is achieved by geometrical limitation that a spherical AuNP is able to touch a plane only at the point. 2. Experimental methods Surface of a glass substrate was coated with 1,1,1,3,3,3-hexamethyldisilazane, which exhibits hydrophobic property. 0.5 mM of n-octadecanamine (C18) in chloroform solution was prepared. A monolayer of C18 was formed at an air/water interface with Langmuir-Blodgett (LB) trough. The monolayer was deposited onto the hydrophobic glass substrate. The glass substrates with the LB film of C18 were soaked for one night in AuNP (45-50 nm) solution. The surface of the glass substrate was covered with AuNPs. The glass substrate covered with AuNPs was sonicated for 5 min in 20 mL of ethanol. AuNPs with C18 were removed from the glass substrate and dispersed in the ethanol. The ethanol solution including AuNPs was concentrated by 8 times. 3. Results and Discussion Figure 1 shows the extinction spectrum of AuNPs, which are decorated partially by C18, dispersed in ethanol. Two peaks are observed in the spectrum at 540 nm and 672 nm. We also show the extinction spectrum of AuNPs aqueous solution (blue). From the comparison between these two extinction spectra it is found that the peak at 672 nm appears newly in the ethanol solution. Similarly, two peaks were reported at around 550 nm and 650 nm from AuNPs (40 nm) dimers with the inter-particle gap of 3.3 nm, which are transverse and longitudinal plasmon Figure 1. Extinction spectra of AuNPs aqueous solution (blue) modes, respectively [3]. AuNP dimers may be and AuNPs decorated partially by C18 in EtOH (red). produced with our fabrication protocol although other AuNP oligomers are included as by-products. 4. References [1] A. Tao, S. Habas, and P. Yang, Small 4, 3, 310-325 (2008). [2] X. Han, J. Goebl, Z. Lu, and Y. Yin, Langmuir 27, 5282-5289 (2011). [3] V. Thacker, L. Herrmann, D. Sigle, T. Zhang, T. Liedl, J. Baumberg, and U. Keyser, Nat. Commun. 4448, 1-7 (2014).
80 Session: WED-R1-S3
Date: March 23 (Wednesday) Time: 13:30-15:00 Session Chair: Prabhat Verma (Osaka University, Japan) ? R . ` . ? 0 7 ? 1 Room: 1st Conference Room (3F) WED-R1-S3 Invited talk
Prof. Vasily Klimov
Russian Academy of Sciences, Russia
New Optical Properties of Perforated Metal Films March 23, 2016 13:30-14:00 and Their Applications 1st Conference Room (3F)
Biography for Vasily Klimov
Prof. Vasily Klimov received both his M.S. (with honours) and PhD degrees in Physics from Moscow State University in 1978 and 1981 respectively. In 1981-1990, he was a Senior Researcher at Naval Research Laboratory (Russia). From 1990 to date, he is a Principal Scientist at Lebedev Physical Institute of Russian Academy of Sciences. In 2001 he received his Doctor of Sciences degree in Physics from Lebedev Physical Institute. Now, he is also the Head of a large project “Quantum Plasmonics” which is funded by Russian Foundation for Advanced Research Projects.
Prof. Klimov is an author of more than 150 research publications and 6 book chapters. In 2009, he issued a book “Nanoplasmonics” that was published in several Russian and international editions. His fields of interest includes quantum electrodynamics and field theory, nano-optics, metamaterials and metasurfaces, wave propagation, particle physics, quantum and classical optics, etc. His main research achievements include: 1) theory of QCD at high temperatures and densities, 2) theory of coherent emission from carbon nanotubes, 3) theory of spontaneous emission of atoms and molecules near nanoparticles of different shapes, 4) theory of plasmonic properties of nanoparticles of complex shapes, 5) theory of focusing light and matter waves by negative refraction, 6) theory of radiation by fast decaying currents.
82 IN-13
New Optical Properties of Perforated Metal Films and Their Applications
Vasily Klimov1,2 1. P.N. Lebedev Physical Institute, Russian Academy of Sciences, 53 Leninsky Prospekt, Moscow 119991, Russia 2. All-Russia Research Institute of Automatics, 22 Sushchevskaya st., Moscow 127055, Russia E-mail address: [email protected]
Abstract: New approaches for manipulation of polarization and spatial properties of light beams with the help of perforated plasmonic films are suggested. These approaches are based on combination of metal films with planar photonic crystals and arrays of nanoholes of different shapes. Possible applications of effects found are discussed.
Many interesting properties of nanoholes in metal films have been already discovered (see e.g.[1]). However, this geometry is very rich, and one can expect a lot of new interesting effects there. In my talk, I will discuss several new optical effects related with nanoapertures in a metal film placed on planar metamaterials with bandgaps.
Fig.1. The asymmetry of transmission of light illuminating Fig. 2. State of polarization in all diffraction orders. Plane our perforated film from top (Tup) and bottom (Tdown). wave with LCP irradiates periodic lattice of left twisted nanoholes. Arrows show rotation direction of the electric field. Clockwise and counterclockwise rotations correspond to RCP and to LCP respectively. Note that this figure shows in fact spatial distribution of polarization. We have shown that due to optical Tamm states the total transmission can be as large as 800% and even more [2]. Then, I will discuss asymmetry effects which are due to absorption in the metal film rather than magnetic field [3]. Here, I will show that the perforated metal film together with the planar metamaterial can provide giant asymmetry in light transmission without any magnetic effects (Fig.1). I will also discuss how one can control spatial and polarization states of light beams with chiral nanoapertures in metal films (Fig.2)[4]. The state of polarization of wave in principal diffraction order coincides with the state of polarization of incident wave, whereas in nm22 2 orders the light has opposite circular polarization! Then, I will discuss molecule fluorescence and lasing near an array of nanoapertures. Here, I will present new analytical, numerical, and experimental results that allow one to understand clearly these complicated phenomena. The research was supported by Advanced Research Foundation (contract number 7/004/2013-2018 on ` 0 0 3 -02-00290 and 15-52-52006) for financial support of this work.
[1] T. W. Ebbesen, H. J. Lezec, H. F. Ghaemi, T. Thio and P. A. Wol, Nature 391, 667 (1998). [2] I. V. Treshin , V. V. Klimov, P. N. Melentiev and V. I. Balykin, Optical Tamm state and extraordinary light transmission through a nanoaperture, Phys. Rev. A 88, 023832 (2013). [3] V. V. Klimov , I.V. Treshin , A. S. Shalin ,P.N. Melentiev , A.A. Kuzin , A. E. Afanasiev , and V. I. Balykin Optical Tamm state and giant asymmetry of light transmission through an array of nanoholes, PRA (accepted) [4] V. V. Klimov, I.V. Zabkov, A.A. Pavlov, G.-Y. Guo, R.-C. Shiu, and H.-C.Chan, Manipulation of polarization and spatial properties of light beams with chiral metafilms , Optics Express (submitted)
83 Oral-11
Luminance Enhancement by the Incorporation of Au Nanoparticles in Polymer Light-Emitting Diodes
Iyan Subiyanto,1 Liu Bei,1 Frances Camille P. Masim,2 Koji Hatanaka,2 Kou-Chen Liu1* 1Department of Electronics Engineering, Chang Gung University, Taoyuan, Taiwan 2Research Center for Applied Sciences, Academia Sinica, Taipei, Taiwan E-mail address: [email protected]
Abstract: The mechanisms of luminance enhancement on plasmonic light-emitting diodes were investigated. In this study, the incorporation of Au nanoparticles into PEDOT:PSS as a hole transport layer material with a specific concentration and thickness was controlled by spin-coating speed. The results showed an efficient performance and enhanced luminance even with leakage current at low applied voltage.
1. Introduction Plasmonic nanoparticles have been introduced as promising materials for the efficient performance of organic light-emitting diode (OLED), however, detailed mechanism on enhancement has not been clearly investigated. Recent studies reported that luminance enhancement mechanism is attributed to hole injection improvement and plasmonic effect. In this study, a layer of poly(3,4-ethylenedioxythiophene) polystyrene sulfonate (PEDOT:PSS) thin film hybridized with Au nanoparticles (AuNPs) was fabricated to demonstrate Au- NPs doping plays the leading effect in luminance enhancement. 2. Experimental detail AuNPs with 12-nm diameter size were synthesized by citrate reduction method [5]. Then, 10 vol. % of AuNPs was mixed with PEDOT:PSS solution. The prepared solution was spin-coated onto the O2 plasma treated ITO-glass substrate. The undoped PEDOT:PSS and Au-NPs doped PEDOT:PSS layers are adjusted to the same thickness by controlling the spin-coating speed. The emitting layer was made by poly(9,9-dioctylfluorene) (PFO) deposited by spin-coating technique. Then, LiF and Al cathodes are deposited by thermal evaporation. 3. Result and discussion Fig. 1 shows 18% luminance enhancement from 19,260 Cd/m2 to 22,840 Cd/m2, the efficiency of device performance was improved with the same percentage after doping with Au-NPs as depicted on the inset of Fig. 1. In Fig. 2 (a), an equal current density was observed in both devices at high voltage region (from 7V to 12V). In the case of the device doped with AuNPs, leakage currents were observed from -5V to 2V as compared to the reference device. Leakage currents were predicted to occur due to the roughness of interface between the PEDOT:PSS layer and PFO layer caused by AuNPs doping [6]. In Fig 2 (b), the increase of roughness causes more traps on the interface between PEDOT:PSS and PFO, indicating that more carriers can cross the barrier and injected into the PFO layer. Hence, the fabricated OLED device demonstrated an efficient performance and enhanced luminance by the incorporation of Au nanoparticles.
Fig. 1. Luminance enhancement of the OLED device Fig. 2. (a) Log scale curves of current injected when doped with 10 vol. % Au-NPs, the inset is the the voltage applied to the devices, correspond to (b) enhancement of device efficiency. the modified energy band diagram model. The inset on figure is the OLED device structure. 4. References [1] D. Wang, K. Yasui, M. Ozawa, K. Odoi, S. Shimamura, and K. Fujita, Appl. Phys. Lett., vol. 102, no. 2, p. 023302, Jan. 2013. [2] P. J. Jesuraj and K. Jeganathan, RSC Adv., vol. 5, no. 1, pp. 684–689, Dec. 2015. [3] Y. Xiao, J. P. Yang, P. P. Cheng, J. J. Zhu, Z. Q. Xu, Y. H. Deng, S. T. Lee, Y. Q. Li, and J. X. Tang, Appl. Phys. Lett., vol. 100, no. 1, p. 013308, Jan. 2012. [4] S. H. Kim, T.-S. Bae, W. Heo, T. Joo, K.-D. Song, H.-G. Park, and S. yoon Ryu, ACS Appl. Mater. Interfaces, vol. 7, no. 27, pp. 15031–41, Jul. 2015. [5] N. G. Bastús, J. Comenge, and V. Puntes, Langmuir, vol. 27, no. 17, pp. 11098–11105, 2011. [6] A. Fujiki, T. Uemura, N. Zettsu, M. Akai-Kasaya, A. Saito, and Y. Kuwahara, Appl. Phys. Lett., vol. 96, no. 4, p. 043307, Jan. 2010.
84 Oral-14
Innovative Low Intensity Light Simulators for Evaluating DSSCs
1,2,3* 2 2 2 2 Der-Ray Huang , Pei-Yu Chuang , Wei-Hsiang Chiang , Yi-An Chen , Jing-Ru Chang 1 Energy Technology Center, National Dong Hwa University, Hualien, Taiwan 2Department of Opto-Electronics Engineering, National Dong Hwa University, Hualien, Taiwan 3Research for Applied Sciences Center, Academia Sinica, Taipei, Taiwan Corresponding author: [email protected] % # & # ¡ ¡ ' {\¨ ` # _\¨ ` _\¨ ` ¡ # & ¡ # ¡ ¡ # # _\¨ ` ` ` `¥ # ¡ ¡ '
85 Oral-17
Size dependent evolution of the resonant mode in porous ZnO spherical microcavity
Buu Trong Huynh Ngo,1,2,3 Ching-Hang Chien 1,2,3 , and Yia-Chung Chang 1,4,* /Research Center for Applied Sciences, Academia Sinica, Taipei, 11529, Taiwan Nano Science and Technology Program, TIGP, Academia Sinica, Taipei 11529, Taiwan %Department of Engineering and System Science, National Tsing Hua University, Hsinchu 30010, Taiwan F U & U *[email protected] Abstract \ \ £ ` # £ ) ' *_= \ \ £ £ *` = % \ # # \ # \ % *_= © £ © 21 _#` `_ *`= ¡ ©£ © ^ ^+ `_ *= £ 6, _|`+ `_{
86 WED-R2-S3
Session: WED-R2-S3
Date: March 23 (Wednesday) Time: 13:30-15:00 Session Chair: % ` 7 ? . 0 7 ] R . ` . 0 7 ? 1 Room: 2nd Conference Room (3F) Invited talk
Prof. Takuo Tanaka
RIKEN, Japan
Metamaterial absorber for attomole level March 23, 2016 13:30-14:00 molecular detection 2nd Conference Room (3F)
Biography for Takuo Tanaka
Takuo Tanaka graduated department of Applied Physics, faculty of Engineering, Osaka University and received his BSc in 1991. After that, he obtained MSc, and PhD all in Applied Physics from the same university in 1993, and 1996, respectively. In 1996, he joined department of Electrical Engineering, faculty of Engineering Science, Osaka University as an assistant professor. In 2003, he moved to Nanophotonics Laboratory in RIKEN as a research scientist. He was promoted to associate chief scientist in 2008, and now he is working as head of the Metamaterials laboratory in the advanced research institute of RIKEN. His research background is three-dimensional microscopy such as confocal microscope and two-photon microscope. He applied these three- dimensional microscope techniques not only observing 3D microstructures of the samples but also fabricating 3D micro/nano structures or 3D optical storage that records and reads digital data in the volume materials. He developed two-photon reduction technique that enables us to fabricate 3D metal nanostructures and this technique is known as ingenious technology of his group in the research community. Recently, he is also developing new nanofabrication techniques that incorporate self-organized formation of metamaterials structures.
88 IN-14
Metamaterial absorber for attomole level molecular detection
Takuo Tanaka1,2 and Atsushi Ishikawa1, 3 1. Metamaterials Laboratory, RIKEN 2-1 Hirosawa, Wako, Saitama 351-0198, JAPAN 2. Innovative photon manipulation research team, RIKEN 3. Graduate School of Natural Science and Technology, Okayama University E-mail address: [email protected]
Abstract: Metamaterial infrared absorber was applied for a background-suppressed surface- enhanced molecular detection technique. By utilizing the resonant coupling of plasmonic modes of a metamaterial absorber and infrared (IR) vibrational modes of a self-assembled monolayer (SAM), attomole level sensitivity was experimentally demonstrated.
1. Introduction IR absorption spectroscopy of molecular vibrations is important technique in the wide fields such as chemistry, material science, medical science and so on, since it provides essential information of the molecular structure, composition, and orientation. In the vibrational spectroscopic techniques, in addition to the weak signals from the molecules, strong background degrades the signal-to-noise ratio, and suppression of the background is crucial for the further improvement of the sensitivity. Here, we demonstrate low-background resonant Surface enhanced IR absorption (SEIRA) by using the metamaterial IR absorber that offers significant background suppression as well as plasmonic enhancement.
2. Experiments and results The fabricated metamaterial absorber consists of 1D array of Au micro-ribbons on a thick Au film separated by a transparent gap layer made of MgF2 as shown in Figure 1. The surface structures were designed to exhibit an anomalous IR absorption at ~ 3000 cm-1, which spectrally overlapped with C-H stretching vibrational modes. The fabricated metamaterial was immersed into a 16-MHDA ethanol solution with a concentration of 103 M. After 48 hours, the surface of the metamaterial was totally covered by a 21.5-Å thick SAM of the 16-MHDA. The IR spectrum of the metamaterial with SAM was measured by a FT-IR spectrometer in the range of 2250 – 3250 cm-1. The measured spectrum was shown in Figure 2. In the FT-IR spectrum, the symmetric and asymmetric C-H stretching modes were clearly observed as reflection peaks within a broad plasmonic absorption of the metamaterial. The respective vibrational signals of the symmetric/asymmetric C-H stretching modes are clearly observable, demonstrating our primary goal of realizing metamaterial-enhanced IR absorption spectroscopy. To quantitatively analyze the vibrational signal, Fano line-shape fitting was also carried out, and we found that the spectral line-shapes of the experimental result were well re-produced by the Fano fitting curves. Using the SAM packing density of 21.4 Å2/molecule, the sensitivity was estimated to be ~1.8 attomoles within the diffraction-limited IR beam spot. From the result, we conclude that our metamaterial approach may open up new doors for further lowering the detection limit of far-field IR vibrational spectroscopy.
Figure 1. Fabricated metamaterial absorber. Figure 2. Metamaterial-enhanced IR absorption. 3. References
[1] A. Ishikawa and T. Tanaka, Scientific Reports 5, 12570 (2015).
89 Oral-12
Giant Plasmonic Circular Dichroism in Ag Staircase Nanostructures [1]
Chunrui Han1, Ho Ming Leung1, C. T. Chan1,2 and Wing Yim Tam1* 1Department of Physics and William Mong Institute of Nano Science and Technology The Hong Kong University of Science and Technology Clear Water Bay, Kowloon, Hong Kong, China 2Department of Physics and Institute for Advanced Study, Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong, China *[email protected]
Abstract: We demonstrate large circular dichroism (CD) in the visible range resulting from electromagnetic couplings in three-dimensional Ag staircase nanostructures. Analytical calculations using effective constitutive parameters show that the CD originates from chiral resonances of the staircase in which the induced magnetic dipole moment has components parallel or antiparallel to the induced electric dipole moment. The strength of the coupling as well as the CD can be tuned by varying the configuration (e.g. the strip width) of staircase nanostructure. More importantly we are able to realize such chiral resonances with large CD in the visible range in topologically similar chiral nanostructures fabricated using a simple shadowing vapor deposition method. Our simple staircase model demonstrates the effect of couplings between electric and magnetic dipole moments in producing large chiral responses in 3D nanostructures and can enhance the understanding of hybrid chiral optical systems.
[1] Chunrui Han, Ho Ming Leung, C. T. Chan, and Wing Yim Tam, Opt. Express23, 33065-33078 (2015).
90 Oral-15
Unidirectional Beaming of Photoluminescence from Gold Yagi-Uda Nanoantenna ġ Kel-Meng See1, Tzu-Yu Chen1, Fan-Cheng Lin1, You-Xin Huang1 and Jer-Shing Huang1 U C C " " U
Abstract: Yagi-Uda (YU) antenna is a promising tool for highly unidirectional beaming of electromagnetic wave. The first YU nanoantennas that work in optical frequency was demonstrated by Alberto G. Curto et al. in 2010 [1], which the nanoantennas are driven by a quantum dots that placed near the resonance feed. However, it is challenging to place the quantum emitters at the feed element of YU nanoantennas with nanoscale precision. Meanwhile, when entering optical and near infrared spectral regime, photons with such energy is high enough to induce the electronic transition in metal which allow metallic nanostructures to emit photoluminescence (PL). The PL of metallic nanostructure is an ideal local light source to drive YU nanoantenna itself due to the nature of broadband, non- blinking and non-bleaching. Here, we study the unidirectional emission of photoluminescence (PL) from gold Yagi Uda nanoantenna. We investigate the directionality of PL emission from YU nanoantennas using back-focal plane imaging technique. We successfully observed unidirectional beaming of 650 nm wavelength PL from a gold YU antenna when it is excited by 532 nm laser on the feed element. The PL wavelength of the YU antenna is designable due to the modulation effect of PL by localized surface plasmon resonance modes. We have also designed YU nanoantenna that emitted PL of 850 nm wavelength at near infrared region, as shown in Fig.1. The experimental results are confirmed by FDTD simulations and dark-field scattering spectra of each single YU element. In addition, we also demonstrate for the first time a bandwidth tunable unidirectional photoluminescence emission from Log-Periodic dipole nanoantennas. The PL of gold YU nanoantenna is an ideal nanoscale unidirectional light source that can be applied in wide field such as high bandwidth wireless optical communication.
Fig 1. (a) SEM image (top panel) and confocal scanning PL image (bottom panel) of YU nanoantenna. The star symbol indicates the position where the laser parked for back-focal plane PL image measurement. (b) Back-focal plane PL image of 850nm wavelength from YU nanoantenna.
References [1] Curto, A. G.; Volpe, G.; Taminiau, T. H.; Kreuzer, M. P.; Quidant, R.; Hulst, N. V., Science, 329, 930M 933 (2010).
91 Oral-18
Narrowband metasurfaces based on Fano resonances
Chen Yan, Kuang-Yu Yang, Olivier J. F. Martin Nanophotonics and Metrology Laboratory, Swiss Federal Institute of Technology Lausanne (EPFL), CH-1015 Lausanne, Switzerland Email: [email protected]
Abstract: Using Fano resonant plasmonic structures as the building blocks for gradient metasurfaces enables spectral selectivity, while preserving spatial directional control. In this work, this concept is demonstrated by a multiplexing device that works in the visible to near-infrared range. We further discuss and compare the different working conditions for the current diffractive optical devices.
Introduction Recently, two-dimensional metasurfaces have become the subject of vivid interest in plasmonics. The arbitrary control of phase at the interface using subwavelength plasmonic nanostructures enables a series of optical devices with small footprint, including optical vortex plates, surface plasmon couplers, and flat lenses [1]. The broadband feature of those devices, as illustrated in Fig. 1(a), limits the usage in other applications such as colorimetric, holograms and photo-multiplexers. On the other hand, Fano resonances that exhibit a unique lineshape are mostly used in near-field applications such as biosensing, SERS and slow light [2]. Combining the above two features enables a new type of device for color-sensitive nano-photonic applications, Fig. 1(b), such as multi-channel data storage, visible demultiplexer and on-chip plasmonic spectrometer. We demonstrated here an efficient narrowband color-routing device that works in the visible to NIR range.
Results The building block is composed of the well-known dolmen structure, where a single nanorod supports a radiative resonance and two parallel nanorods support a narrow dark resonance [3]. The reflection spectrum is shown in Fig. 1(d), where a strong reflection window occurs between two absorption dips. Detuning the resonance frequency of the dark resonance with respect to the fixed radiative resonance will only result in the phase variation of the light in the Fano windows. Thus, by carefully designing the size of dolmen structures in a supercell, one can realize anomalous reflection of light restricted to a certain band with a bandwidth smaller than 100 nm. The design concept is shown in Fig. 1(e), where the geometric phase along the interface is a function of the wavelength. To further reveal the advantages of both spatial and spectral beam steering, we present a dual-color routing metasurface (maxima at 532 nm and 660 nm) with high directionality, Fig. 1(c). The experimental Fourier image is shown in Fig. 1(f), with 50 nm working bandwidths for both channels. Such a color-routing device exhibits highly directional emission. Also the tuning bands do not vary with incident angle, unlike conventional devices. The design principle can be extended to cover a wide range of frequencies from visible to mid-infrared.
[1] Yu N, Capasso F. "Flat optics with designer metasurfaces". Nat Mater 13, 139-150 (2014). [2] Luk'yanchuk B, et al. "The Fano resonance in plasmonic nanostructures and metamaterials". Nat Mater 9, 707-715 (2010). [3] Yan C, Martin O J. "Periodicity-Induced Symmetry Breaking in a Fano Lattice: Hybridization and Tight- Binding Regimes". ACS nano 8, 11860-11868 (2014).
92 Session: WED-IC-S4 WED-IC-S4
Date: March 23 (Wednesday) Time: 15:30-17:10 Session Chair: ! 0 ]8 8 = 1 ? . 7 1 < 0 7 = . % Room: Invited talk
Prof. L. (Kobus) Kuipers
FOM institute AMOLF, Amsterdam, The Netherlands
Nanoscale vector fields -visualization, fascination March 23, 2016 15:30-16:00 and application International Conference Hall (4F)
Biography for L. (Kobus) Kuipers
Kobus Kuipers is Head of the Center for Nanophotonics at the FOM institute AMOLF and professor at the Universities of Twente, Utrecht and Delft. He completed his PhD in surface science (1994). He started his research in nano-optics in 1997 at the University of Twente. He pioneered the visualization of light fields in nanophotonic structures, gaining access to the phase evolution, ultrafast dynamics and vector nature of nanoscale light. In 2000 he became a program director of the MESA+ Institute for Nanotechnology. In 2003 he moved to the FOM Institute AMOLF. Kuipers is a Fellow of the Optical Society of America and the recipient of an Advanced ERC grant on the (ultrafast) control of nanoscale vector fields. He is member of the editorial board of Optica the flagship journal of OSA. His current research interests are slow light, structured light, ultrafast nanoscale optics and near-field microscopy.
Kobus has published 150 papers in refereed international journals of which 2 in Science, 9 in a Nature-group journal and 25 in Physical Review Letters. (in total 57 papers (38%) with an impact ` 8 . ] 0 @ 1. . keynote and plenary talks.
94 IN-15
Nanoscale vector fields # #
L. (Kobus) Kuipers Center for Nanophotonics, FOM institute AMOLF, Amsterdam, The Netherlands E-mail address: [email protected] Abstract: \ \
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95 Invited talk
Prof. Joseph W. Haus
University of Dayton, USA
Third-Harmonic Generation in Titania/Silver March 23, 2016 16:00-16:30 Photonic Crystals International Conference Hall (4F)
Biography for Joseph W. Haus
Joseph W Haus is a professor of Electro-Optics, Electrical and Computer Engineering and Physics at the University of Dayton. His professional journey included several positions including: a NRC post-doctoral fellow at the National Bureau of Standards; a visiting scientist at the Kernforschungsanlage in Jülich Germany; an assistant at the Universität Essen GHS, and a sabbatical year at the University of Tokyo. He was a physics faculty member at Rensselaer Polytechnic Institute for 15 years rising to the rank of professor. In 1999 he was appointed Director of the Electro-Optics Program at the University of Dayton and served for 13 years in that position. Haus is a fellow of the APS, SPIE and OSA. His research interests include nonlinear and quantum phenomena in nanostructured materials and fiber lasers and sensors. He has around 200 journal publications. He is a founding chair of the International Conference on Nanophotonics. He serves as an associate editor on two journals, including the Associate Editor in Chief of Chinese Optics Letters.
96 IN-18
Third-Harmonic Generation in Titania/Silver Photonic Crystals
Han Li1, Joseph W. Haus1,2,3 and Partha P. Banerjee1,2 1 Electro-Optics Program, University of Dayton, Dayton, OH 45469 2 Electrical and Computer Engineering Department, University of Dayton, Dayton, OH 45469 3 Department of Physics, University of Dayton, Dayton OH 45469
Abstract: We report new simulation results on third-harmonic generation in metallodielectric stacks consisting of nanometer scale films of TiO2 (titania) and silver. Using published data for the properties of the constituent materials, our calculations are performed using the transfer matrix method extended to oblique incident fields. We report the transmitted and reflected third- harmonic conversion efficiencies as a function of the metal and dielectric layer thicknesses.
Summary Investigation of second- and third-harmonic generation in optical materials have contributed to important research advances with data cataloged in handbooks since discovery of the first laser [1]. For periodic multi- layer systems, also known as 1D photonic crystals, the enhancements can be several orders of magnitude [2], but there are severe bandwidth limits at the same time. Specifically, we examine third-harmonic generation (THG) using thin-film metallodielectric layers comprised of titania (dielectric) and silver (metal). Amorphous titania has a high refractive index (around 2.3) and silver (Ag) has a complex permittivity that is also strongly dispersive. Due to interference and evanescent field penetration through the metal layers the transmission is much higher than for a single thick metal film. We treat the problem of THG in the silver-titania metallodielectric structure [2-3] by applying the transfer matrix method. The method is extended to treat nonlinear polarization contributions. It has also been extended to obliquely incident fields [4], where second-harmonic generation was examined. The treatment of THG in this talk is an extension of the method developed in Ref. [4]. The reflected and transmitted third- harmonic efficiencies are optimized by varying each layer thickness within experimentally reasonable limits. We show the transmitted third-harmonic efficiency as the thickness of the titania and silver layers are varied. For higher intensity fields the efficiency increases quadratically with intensity.
References [1] V. G.Dmitriev, G. G. Gurzadyan, D. N. Nikogosyan, C , Springer, Berlin, 1999. [2] M. Scalora, M. Bloemer, A. S. Manka, J. P. Dowling, C. M. Bowden, R. Viswanathan, and J. W. Haus, “Pulsed second-harmonic generation in nonlinear, one-dimensional, periodic structures,” Phys. Rev. A56, 3166-3174 (1997). [3] M. Scalora, M. J. Bloemer, A. S. Manka, S. D. Pethel, J. P. Dowling, and C. M. Bowden, “Transparent, metallo-dielectric, one-dimensional, photonic band-gap structures,” J. Appl. Phys. 83, 2377-2383 (1998). [4] H. Li, J. W. Haus, and P. P. Banerjee, "Application of transfer matrix method to second-harmonic generation in nonlinear photonic bandgap structures: oblique incidence," J. Opt. Soc. Am. B 32, 1456- 1462 (2015).
97 Oral-19
Multiphase Optofluidics on an Electromicrofluidic Platform
Shih-Kang Fan U
Abstract: A general electromicrofluidic (EMF) platform employing electrowetting-on- dielectric (EWOD) and dielectrophoresis (DEP) to actuate microfluids between glass plates containing proper electrodes has been developed. For the simple sandwich structure (glass/fluids/glass) without sophisticated microchannels, the EMF platform is easily fabricated, packaged, and operated. On a general EMF platform, EWOD efficiently alters the contact angle of aqueous droplets and has been widely studied in droplet actuations; while DEP drives polarizable particles and liquids by non-uniform electric fields. By skillfully integration of EWOD and DEP, we demonstrated various microfluidic functions on the EMF platform that is general to manipulate (1) fluids with diverse electric properties (water and oil droplets, gas bubbles, and plasma), (2) objects on different scales and in varied phases (mm droplets and )m particles/cells), and (3) liquids in distinct geometries (discrete droplets and continuous virtual microchannels). For the diverse material phases used on an EMF platform, exploiting the electro-optical properties of matter in varied phases is essential to reap the benefits of the optofluidic capabilities of that platform. Materials in the four fundamental phases M solid-phase dielectric layer, liquid-phase droplet, gas-phase bubble, and plasma-phase bubble microplasma M have been investigated to offer electrically tunable optical characteristics for the manipulation of fluids on an EMF platform. By combining the various materials possessing diverse electro-optical characteristics in separate phases, the EMF platform becomes an ideal platform for integrated optofluidics.
98 Oral-22
Cost-effective and visible-light-driven photocatalyst for green applications
Chih-Ming Wang C C (& U
Abstract: In this paper, we demonstrate two kinds of cost-effective photocatatlysts, Cu2O and-Fe2O3, for green applications such as water splitting and photodegradation of methylene blue. Both of the investigated photcatalysts are active under visible light irradiation. This makes the photocatalysts holds potential as high efficient catalyst. Additionally, the plasmonic enhanced photocatalysis reaction is also investigated.
Semiconductor photocatalytic materials show great potential in energy shortage and environment-related applications owing to their unique abilities, such as the decomposition of organic pollutants, H2 evolution from water, CO2 conversion, and heavy-metal ion reduction. Among these versatile applications, cost- effective operation is the most import issue which decides if the photocatalyst can be applied for mass production. Therefore, photocatalyst with cheap fabrication processes and visible-active photocatalytic reactivity is the most desired.
Cu2O and Alpha-Fe2O3 (-Fe2O3, hematite) are both cheap and abundant, and has a suitable band gap for redox reaction of water. Therefore, both of Cu2O and -Fe2O3 hold a high potential as an efficient photocatalyst for photocatalytic water splitting due to its appropriate band gap. In this paper, samples are prepared based on low energy consumption processes. The photocatalytic activity of the prepared samples, Cu2O and -Fe2O3, have been evaluated by photodegradation of methylene blue (MB). Both of the photocatalysts show high H2 evolution rate from pure water splitting under visible light illumination. Additionally, the plasmonic enhanced photocatalysis reaction is also investigated. Based on the plasmon-assisted surface enhanced absorption, the H2 evolution rate can be enhanced 1.85 folds and 1.15 folds for Cu2O and -Fe2O3, respectively.
[1] W. T. Kung, Y. H. Pai, Y. K. Hsu, C. H. Lin and C. M. Wang, Opt. Express. 21, p. A221-A228 (2013) [2] C. M. Wang and C. Y. Wang, J. Nanophotonics 8, p. 084097-084097 (2014)
99
Session: WED-R1-S4
Date: March 23 (Wednesday) Time: 15:30-17:10
Session Chair: Vasily Klimov (Russian Academy of Sciences, Russia) WED-R1-S4 . R ` ? 1 ! 0 7 ? 1 Room: 1st Conference Room (3F) Invited talk
Prof. Mikhail Noginov
Norfolk State University, USA
Light-Matter Interactions in Weak and Strong March 23, 2016 15:30-16:00 Coupling Regimes 1st Conference Room (3F)
Biography for Mikhail Noginov
MIKHAIL A. NOGINOV graduated from MOSCOW INSTITUTE FOR PHYSICS AND TECHNOLOGY (Moscow, Russia) with a Master of Science degree in Automatics and Electronics in 1985. In 1990 he received a Ph.D. degree in Physical-Mathematical Sciences from GENERAL PHYSICS INSTITUTE OF THE USSR ACADEMY OF SCIENCES (Moscow, Russia). 5Appointments: GENERAL PHYSICS INSTITUTE OF THE USSR ACADEMY OF SCIENCES (Moscow, Russia) Engineer, Junior Staff Research Scientist, Staff Research Scientist (1985-1991) MASSACHUSETTS INSTITUTE OF TECHNOLOGY, Cambridge, MA; Center for Materials Science and Engineering; Post Doctoral Research Associate (1991-1993) ALABAMA A&M UNIVERSITY, Huntsville, AL, Assistant Research Professor, Associate Research Professor (1993-1997) NORFOLK STATE UNIVERSITY (NSU), Norfolk, VA, Department of Physics, Center for Materials Research. Research Associate Professor, Assistant Professor, Associate Professor, and Professor (1997-present) 5Honors: NSU Eminent Scholar 2010-2011. Fellow of the Optical Society of America 2014. Fellow of the SPIE 2015. Virginia’s Outstanding Scientist 2015. General Chair of the CLEO conference. 5Publications: Three books, six book chapters, over 140 papers in peer reviewed journals, over 200 publications in proceedings of professional societies and conference technical digests. 5Professional service: Member of OSA, SPIE, and APS. Served as a chair and a committee member of many conferences of SPIE and OSA. Regularly serves on the National Science Foundation (NSF) panels and reviews papers for many professional journals. Since 2003 – faculty advisor of the OSA student chapter at NSU. Editorial Board Member: Scientific Reports, Advanced Optical Technologies. 5Research interests: Metamaterials, Nanoplasmonics, Random Lasers, Solid-State Laser Materials, and Nonlinear Optics.
102 IN-16
Light-Matter Interactions in Weak and Strong Coupling Regimes
V. N. Peters1, E. K. Tanyi1, T. U. Tumkur1,2, H. Thuman3,4, J. Ma,5,6 N. A. Kotov6,7, E. E. Narimanov8, M. A. Noginov1* 1 Center for Materials Research, Norfolk State University, Norfolk, VA, 23504 2 Department of Electrical and Computer Engineering, Rice University, Houston, TX 77005 3 Summer Research Program, Center for Materials Research, Norfolk State University, Norfolk, VA, 23504 4 Department of Materials Science and Engineering, Cornell University, Ithaca, NY 14850 5 Department of Chemical Engineering, University of Michigan, Ann Arbor, MI 48109 6 Department of Chemical Engineering, Xi’an University of Architecture and Technology, Xi’an, China, 710055 7Biointerfaces Institute, University of Michigan, Ann Arbor, MI 48109 8 Birck Nanotechnology Center, Department of Electrical and Computer Engineering, Purdue University, West Lafayette, IN 47907, USA [email protected]
Abstract: We will discuss control of light-matter interactions with metamaterials and metal-dielectric structures occurring in weak and strong coupling regimes.
A broad scope of physical phenomena is pertinent to control of light-matter interactions with metamaterials and simpler metal/dielectric structures. Recent theoretical [1] and experimental efforts have shown that hyperbolic metamaterials can control the rate [2,3], the directionality [4] and the spectra [5] of spontaneous emission. This concept has been later extended to include (i) the effect of lamellar metamaterials on stimulated emission [6], (ii) the effect of the fishnet structure on electric dipole and magnetic dipole spontaneous emission of Eu3+ ions [7], and (iii) Förster energy transfer [8]. The latter phenomenon reportedly occurs in the regime of weak coupling of light and matter. An even more efficient control of light-matter interaction is possible in the regime of strong coupling of e.g. excitons and surface plasmons and nanocavities. As the first step in this direction, we have demonstrated that excited molecules couple with surface plasmon polaritons differently than the ground state molecules do. In another particular experiment, we show that coupling of localized plasmons with dye molecules results in rich Fano resonance structure. Arguably, the most dramatic effect of strong coupling on the spectra, quantum yield and directionality of spontaneous emission is found in cavities with optimized resonance frequency. These and other light-matter interaction effects will be discussed at the conference.
[1] Z. Jacob, I. Smolyaninov, and E. E. Narimanov, Appl. Phys. Lett, 100, 181105 (2012). [2] M. A. Noginov, H. Li, Yu. A. Barnakov, D. Dryden, G. Nataraj, G. Zhu, C. E. Bonner, M. Mayy, Z. Jacob, E. E. Narimanov, Opt. Lett. 35, 1863-1865 (2010). [3] T. Tumkur, G. Zhu, P. Black, Yu. A. Barnakov, C. E. Bonner, and M. A. Noginov, Appl. Phys. Lett. 99, 151115 (2011). [4] L. Gu, J. E. Livenere, G. Zhu, T. U. Tumkur, H. Hu, C. L. Cortes, Z. Jacob, S. M. Prokes, M. A. Noginov, Scientific Reports 4, 7327 (2014). [5] Lei Gu, T. U. Tumkur, G. Zhu, M. A. Noginov, Scientific Reports 4, 4969 (2014). [6] J. K. Kitur, L. Gu, T. Tumkur, C. Bonner, and M. A. Noginov, “Stimulated emission of surface plasmons on top of metamaterials with hyperbolic dispersion”, ACS Photonics, 2, 1019-1024 (2015). [7] R. Hussain, S. S. Kruk, C. E. Bonner, M. A. Noginov, I. Staude, Y. S. Kivshar, N. Noginova, D. N. Neshev, Opt. Lett. 40, 1659-1662 (2015). [8] T. U. Tumkur, J. K. Kitur, C. E. Bonner, A. N. Poddubny, E. E. Narimanov and M. A. Noginov, Faraday Discussions 178, 395-412 (2015). [9] T. U. Tumkur, G. Zhu, M. A. Noginov, accepted for publication in Optics Express.
103 Invited talk
Prof. Ewa Kowalska
Hokkaido University, Japan
Plasmonic photocatalysts for environmental March 23, 2016 16:00-16:30 applications 1st Conference Room (3F)
Biography for Ewa Kowalska
Research work on Advanced Oxidation Processes by Prof. Kowalska started in 1996 when she was a M.Sc. course student at Gdansk University of Technology (Poland), including 9-month research stay at University Paris-Sud (France) during Marie Curie Fellowship from European Commission (2002/2003). She got Ph.D. under the supervision of Professor Jan Hupka in 2004 on “Investigations of photochemical degradation of organic compounds”. Since then she has been studying photochemical purification of (waste)water, heterogeneous photocatalysis, noble metals, plasmonic photocatalysis and related topics at Gdansk University of Technology, Hokkaido University (Japan, JSPS fellowship 2005-07 & GCOE fellowship 2007-09), Friedrich- Alexander University of Erlangen-Nuremberg (Germany, Marie-Curie Fellowship from European Commission, 2009-11) and Ulm University (Germany, BSLP stipend, 2012). In 2013 she was appointed associate professor and leader of research cluster on Plasmonic Photocatalysis in the Institute of Catalysis at Hokkaido University. At present, her research focuses on plasmonic photocatalysis for environmental purification, including research for Bill and Melinda Gates Foundation on “Materials for Food Storage with Antiseptic Properties”, and “Solar Photocatalysis for Generation of Fuel” within a framework of Concert-Japan project.
104 IN-19
Plasmonic photocatalysts for environmental applications
Ewa Kowalska,1* Maya Endo,1 Agata Markowska-Szczupak,2 Zhishun Wei,1 Marcin Janczarek,1,3 Lorenzo Rosa,4 Saulius Juodkazis,4 Bunsho Ohtani1 1Hokkaido University, Sapporo, Japan; 2West Pomeranian University of Technology, Szczecin, Poland; 3Gdansk University of Technology, Gdansk, Poland; 4Swinburne University of Technology, Australia *E-mail address: [email protected]
Abstract: Plasmonic photocatalysts prepared by deposition of Au and/or Ag nanoparticles on titania particles have been used successfully for decomposition of both chemical and microbiological pollutants under visible light irradiation.
1. Introduction R ticles (Au NPs) [1], a lot of research has been carried out to explain nature of catalytic reaction and to find optimal conditions for efficient oxidation of organic compounds. Regarding catalytic and plasmonic properties of Au NPs, the novel area of research on photocatalytic Au properties has recently been started. In contrast with catalytically active gold NPs, where nano-sized Au is recommended, our results showed that polydispersity of deposited Au NPs on semiconducting support was beneficial for photocatalytic activity under visible light irradiation [2]. It is thought that wide size/shape distribution of Au NPs, and thus the ability of absorption of light in a wide wavelengths range is responsible for the high level of photocatalytic activity. The action spectrum analysis has proved that visible light-induced oxidation of organic compounds by Au-modified titania is initiated by excitation of Au surface plasmon [3]. 2. Results Plasmonic photocatalysts can decompose both chemical (acetic acid, methanol, 2-propanol, phenol) and microbiological (bacteria and fungi) pollutants. The mineralization of bacteria cells and inhibition of mycotoxin generation under visible light irradiation indicate possible applications of these photocatalysts as solar active nanomaterials for environmental purification [4,5]. Though desirable absorption properties of plasmonic photocatalysts can be easily obtained by preparation of NPs of different sizes and shapes, their photocatalytic activities under visible light irradiation are still low and should be enhanced. The improvement of photocatalytic activities under visible light irradiation could be achieved by: i) enlargement of interface between titania and NPs of noble metals (e.g., by partial coverage of gold NPs with fine titania NPs (Fig. 1a)), ii) extension of photoabsorption ranges (e.g., by preparation of NPs of various sizes and shapes [6], composed of two noble metals (e.g., Ag-Pt [7], Au-Ag, Fig 1b [8]), or combined with homogeneous photocatalysts (e.g., ruthenium complexes [9])), and iii) deposition of noble metals NPs on facetted titania, i.e., octahedral (OAPs) and decahedral (DAPs) anatase particles (Fig. 1c-d) [4].
n = 1.3 large 20 nm 80 nm titania Au OAP (Aldrich r) TiO n=2.7 2
DAP TiO fine 2 Au titania OAP Ag Ag (STO1) Au Ag 50 nm 10 nm TiO (a) 2 (b) (c) (d)
Fig. 1. (a) STEM image of TiO2/Au/TiO2 obtained; (b) the cross-sectional pattern of the near-field intensity enhancement factor for 10 nm x 10 nm x 30 nm gold NP on the presence of coverage layer of silver of thickness t for: (top) t=0 at 510 nm wavelength, (middle) t=2 nm at 600 nm, bottom t=5 nm at 570 nm, n-refractive index [8]; c-d) STEM images of Ag NPs deposited on OAPs & DAPs [4]. References [1] M. Haruta, T. Kobayashi, H. Sano, N. Yamada, Chem. Lett. 2, 405-408 (1987). [2] E. Kowalska, R. Abe, B. Ohtani, Chem. Commun., 2, 241-243 (2009). [3] E. Kowalska, O.O.P. Mahaney, R. Abe, B. Ohtani, Phys. Chem. Chem. Phys., 12, 2344-2355 (2010). [4] E. Kowalska, Z. Wei, B. Karabiyik, M. Janczarek, A. Markowska-Szczupak A., Ohtani B. Adv. Sci. Technol. 93, 174-183 (2014). [5] E. Kowalska, Z. Wei, B. Karabiyik, M. Endo, A. Markowska-Szczupak, H. Remita, B. Ohtani, Catal. Today 252, 136-142 (2015). [6] E. Kowalska E., S. Rau, B. Ohtani, Journal of Nanotechnology Article ID 361853 (2012). [7] A. Zielinska-Jurek, Z. Wei, I. Wysocka, P. Szweda, E. Kowalska, Appl. Surf. Sci. 353 317-325 (2015). [8] E. Kowalska E., M. Janczarek, L. Rosa, S. Juodkazis, B. Ohtani Catal. Today 230, 131-137 (2014). [9] E. Kowalska, K. Yoshiiri, Z. Wei, S. Zheng, E. Kastl, H. Remita, B. Ohtani, S. Rau, Appl. Catal. B- Environ. 178, 133-143 (2015).
105 Oral-20
Tailoring light-matter interaction in plasmonic nanoantennas
Emiliano Cortés, Stefan A. Maier Department of Physics, Imperial College London, London SW7 2AZ, United Kingdom [email protected]
Abstract: Materials that exhibit plasmonic resonances allow for intense light-focusing, thereby enabling electromagnetic (EM) energy transfer from the far to the near field or vice versa. Properly structured, these materials allow for the fabrication of elements that can be considered as optical nanoantennas and are key to fabricate devices for the conversion of free-space light to nanometre-scale volumes [1]. Different processes are triggered when light impinges on a plasmonic nanoantenna [2]. Depending on the time scale under evaluation, important information can be extracted from this interaction. Initially, when light hits the nanoantenna, many ultra-fast processes like electronic relaxation and lattice vibrations take place [3, 4]. After that, light is focused in high EM regions (hot-spots) where the interaction with molecules and/or other nanomaterials (i.e. quantum dots) can be enhanced. Finally, the light is re-emitted to the far field [5]. We approach the challenge of studying these both extremes (from ultra-fast process to re- emission of light) by employing degenerate pump-probe techniques with double modulation and super-resolution optical microscopy. We show how the phononic response of antenna can be modified without affecting its plasmonic properties, and also the importance of the local density of states when the antenna interacts with molecules nearby. Thus we provide new insights of different practical approaches to tailor the response of plasmonic antennas by studying this light-matter interaction from different perspectives.
[1] Gianinni, V.; Fernandez-Dominguez, A. I.; Heck, S. C.; Maier, S. A. Chem. Rev. 2011, 111, 3888 [2] Maier, S. A. Plasmonics: Fundamentals and Applications, Springer, 2007 [3] ORBrien, K.; Lanzillotti-Kimura, N. D.; Rho, J.; Suchowski, H.; Yin, X.; Zhang, X. Nat. Commun. 2014, 5, 4042 [4] Chang, W.-S.; Wen, F.; Chakraborty, D.; Su, M.-N.; Zhang, Y.; Shuang, B.; Nordlander, P.; Sader, J. E.; Halas, N. J.; Link, S. Nat. Commun. 2015, 6, 7022 [5] Cang, H.; Labno, A.; Lu, Ch.; Yin, X.; Liu, M.; Gladden, Ch.; Liu, Y.; Zhang X. Nature 2011, 469, 385
106 Oral-23
Ag- and Al-based surface plasmon polariton nanolasers
Tien-Chang Lu1*, Yu-Hsun Chou1, 2, Yen-Mo Wu1, Kuo-Bin Hong1, Bo-Tsun Chou3, Jheng-Hong Shih4, Yi-Cheng Chung4, Tzy-Rong Lin4, 5, Chien-Chung Lin2, and Sheng-Di Lin3 U C U U U U " U C U U F U $ U F U
Abstract: Nanolasers with ultraĮcompact footprint can provide high intensity coherent light, which can have various potential applications in high capacity signal processing, biosensing, and sub-wavelength imaging. Among various nanolasers, those lasers with cavities surrounded with metals have shown to have superior light emission properties due to the surface plasmon effect providing better field confinement capability and allowing exotic lightĮmatter interaction. In this talk, we report robust ultraviolet ZnO nanolaser by using silver (Ag) and aluminum (Al) to strongly shrink the mode volume. The nanolasers operated at room temperature shows several distinct features including an extremely small mode volume, large Purcell factor and group index. Comparison of characteristics between Ag- and Al-based will also be made.
107
Session: WED-R2-S4
Date: March 23 (Wednesday) Time: 15:30-17:10 Session Chair: Takuo Tanaka (RIKEN, Japan) . R . . ` . 0 7 ? 1 Room: 2nd Conference Room (3F) WED-R2-S4 Invited talk
Prof. Cheng Wei Qiu
National University of Singapore, Singapore
Nano-manipulation of Spin-Orbital Angular March 23, 2016 15:30-16:00 Momentum via Visible-frequency Metasurfaces 2nd Conference Room (3F)
Biography for Cheng Wei Qiu
Prof. Cheng-Wei Qiu received his B.Eng. and Ph. D. degree in 2003 and 2008, respectively. He was a Postdoctoral Fellow at Physics Department in MIT till the end of 2009. Since December 2009, he joined NUS as an Assistant Professor. He was the recipient of the SUMMA Graduate Fellowship in Advanced Electromagnetics in 2005, IEEE AP-S Graduate Research Award in 2006, URSI Young Scientist Award in 2008, NUS Young Investigator Award in 2011, MIT TR35 Award in Asia Pacific in 2012, Young Scientist Award by Singapore National Academy of Science 2013, and Faculty Young Research Award in NUS 2013. His research interests are in the areas of electromagnetic wave theory of transformation optic metamaterials, light-matter interaction, and nanophotonics. He has published over 120 journal peer-reviewed papers and his research has received a lot of press coverage by Science, Viewpoint Physics, PRL Synopsis, Physics World, Phys.Org, ScienceDaily, MIT Technology Review, Daily Mail (UK), Straits Times (Singapore), Le Monde, SPIE Newsroom, A&EN etc.
110 IN-17
Nano-manipulation of Spin-Orbital Angular Momentum via Visible-frequency Metasurfaces
M. Q. Mehmood, Mei Shengtao, and Cheng-wei Qiu " &$'" )
Abstract: We theoretically propose and experimentally demonstrate a multi-foci metasurface for spin-orbital angular momentum interaction. Compared with traditional lens, such flat lens takes the advantage from its ultrathin trait to realize the helicity-dependent optical vortex focusing metalens (consisting of 306,306 rotating nano-voids) that focuses three longitudinal vortices with distinct topological charges at different focal planes1. Meanwhile, we observe the multi orbital angular momentum foci with opposite topological charges on both sides of the metalens. The designed metasurface may find potential applications in multi-plane simultaneously particles manipulation, angular-momentum-based quantum information processing and integrated nano-optoelectronics. On the other hand, an on-chip discrimination scheme of detecting the orbital angular momentum of light was experimentally demonstrated to focus the surface plasmons to different lateral positions, with reliable 120nm lateral shift between any two neighboring topological charges of the incident vortex light.
Recently, an intriguing two dimensional metamaterial, named the metasurface2, has gained attention due to its eminent phase modulation ability for anomalous reflection and refraction. The idea revolutionizes the concept of phase modulation by providing phase control at the nanoscale and paves an avenue towards the construction of a wide range of ultrathin optical devices and effects. Such phase-modification abilities potentially allowed to significantly reduce the size of optical vortex generators. In this regard, Yu et al.2 and Genevet et al.3 demonstrate the generation of vortex beam via a metasurface. Their V-shaped nano-rods respond to the linear polarization, where helical beam was obtained for the cross polarization. The concept of anomalous reflection/refraction was further extended to circularly polarized illumination4 and spin-orbit interaction was exploited to achieve an ultrathin spiral phase plate for cross-circular polarized light4. However, those optical vortex plates were restricted to creating one specific topological charge ( ) for a fabricated device, whereas a separate device would be required (every time) to attain different topological charges. Moreover, such devices yield a propagating optical vortex instead of concentrated photons. Such constraints may limit their use in applications where highly concentrated optical vortices with different topological charges are encountered. The presence of well-defined focal plane with highly concentrated light is an essential ingredient for optical trapping and manipulation. Apart from the metasurface, although spiral zone plates provide an opportunity for focused OAM generation as stand-alone devices, their overall large size and unobtainability of multiple focal planes with distinct topological charges, are less desirable. In this work, we employ the concept of controllable interfacial phase discontinuity and merge the corresponding phases of the two distinct optical devices, a lens and a spiral phase plate, into a single metasurface to realize an ultrathin nanostructured optical vortex plate with multiple focal planes. The proposed device can have multiple focal planes along the longitudinal direction, whereas the number of focal planes, corresponding topological charges and focal lengths can readily be tailored to meet any requirement. Unlike traditional diffractive spiral phase and zone plates, this lens is ultrathin (60 nm), compact and can have multiple focal planes. The polarization state and position of the focal planes can be controlled by manipulating the helicity of the incident light. The constructive or destructive interference of light, at the focal plane, scattered through nano-bars which will be described, is rigorously controlled by the handedness of the incident light. As a counterpart, we also experimentally validated a plasmonic surface to discriminate and focus surface plasmons into stably predictable lateral positions on the plasmonic film, which functions as an on- }
References [1] M. Q. Mehmood, Shengtao Mei, Sajid Hussain, Kun Huang, S. Y. Siew, Lei Zhang, Tianhang Zhang, Xiaohui Ling, Hong Liu, Jinghua Teng, Aaron Danner, Shuang Zhang, and Cheng-Wei Qiu, "Visible- frequency Metasurface for Structuring and Spatially Multiplexing Optical Vortices," Advanced Materials (2015). [2] Yu, N.; Genevet, P.; Kats, M. A.; Aieta, F.; Tetienne, J. P.; Capasso, F.; Gaburro, Z. Science 2011, 334, (6054), 333-337. [3] Genevet, P.; Yu, N.; Aieta, F.; Lin, J.; Kats, M. A.; Blanchard, R.; Scully, M. O.; Gaburro, Z.; Capasso, F. Appl. Phys. Lett. 2012, 100, 013101. [4] Huang, L.; Chen, X.; Muhlenbernd, H.; Li, G.; Bai, B.; Tan, Q.; Jin, G.; Zentgraf, T.; Zhang, S. Nano letters 2012, 12, 5750-5755.
111 Invited talk
Prof. Seung-Han Park
Yonsei University, Korea
Multimodal Nonlinear Optical Microscopy for March 23, 2016 16:00-16:30 In-vivo and Label-free Biological Imaging 2nd Conference Room (3F)
Biography for Seung-Han Park
Seung-Han Park received his B.S. and M.S. degrees in Physics from Yonsei University, Korea, in 1982 and 1984, respectively, and Ph. D. degree from the Optical Sciences Center at the University of Arizona, in 1988. After working as an assistant professor in the Dept. of Electrical Engineering at the University of Pittsburgh, he joined the Dept. of Physics, Yonsei University, Seoul, Korea, in 1991, where he is currently a professor. Currently, he is working as the Dean of College of Science.
His research focus has been on the development, understanding, and applications of quantum confinement effects in semiconductor nano-structures, plasma resonance of metallic particles, local-field effects in metal- semiconductor nano-composite materials, and nano-bio sensing, imaging and spectroscopy. His research works resulted in distinct scientific contributions with over 150 publications in major referred journals and around 230 presentations in domestic and international conferences. He was the director for National Research Laboratory (2002-2007) and the director of Pioneer Research Center for Neuro-Science and Technology (2008-2014). He is the recipient of Grand Academic Award (2015) from Optical Society of Korea. He is a member of OSK, KPS, SPIE, and OSA and a fellow of SPIE.
112 IN-20
! < + " < > + $ $ \& & ( F
Recently, multimodal nonlinear optical microcopy has attracted much attention due to its various advantages including intrinsic optical sectioning and label-free imaging capabilities with sub-cellular resolution. In this microscopy, and label-free morphological and fluorescent images can be obtained from biological sample by nonlinear interactions such as second-harmonic generation (SHG) and third- harmonic generation (THG) together with two-photon absorption. Video-rate multimodal microscope, which can obtain second and third harmonic generation (SHG and THG) images simultaneously, is also developed for investigating cellular and tissue structures in mouse ear skin. [1-3] In this presentation, high-speed multimodal laser scanning microscope, designed for acquiring fast moving cell tracking in a live animal, are introduced. The microscope has multiple functional modalities: one- photon confocal, two-photon, SHG, and THG microscopy. By using our custom-built multimodal laser scanning microscope, we can obtain confocal, two-photon, SHG and THG images simultaneously from the live animals. The frame rates of the microscope is 30.3 [f/s] at 791×512 image pixels. However, frame rates can be increased or decreased by changing the number of vertical pixels of the frame. The maximum frame rate can be achieved up to 1130.4 [f/s] at 791×4 image pixels. An Ytterbium doped femtosecond laser oscillator of 1036 nm with repetition rate of 50 MHz is utilized as an excitation source. The pulse duration and average power are ~154 fs and ~1 W. and label-free images from various biological samples will be demonstrated. In particular, high- resolution images of inner ear, brain, and peripheral tissues of zebrafish larvae without employing fluorescent probes will be presented. In addition, image of subcutaneous cellular components and peripheral nerve fibers together with the collagen fiber in the mouse ear pinna will be displayed. D E F
Fig. 1. Zebrafish anus images obtained by multimodal nonlinear optical microcopy; (a) SHG image, (b) THG image, and (c) merged image.
[1] , Appl. Phys. Lett. , 922-924 (1997). [2] Yelin D, Silberberg Y, Laser scanning third-harmonic-generation microscopy in biology , Opt. Express `, 169M175 (1999). [3] Debarre D, et al., Imaging lipid bodies in cells and tissues using third-harmonic generation microscopy , Nature Methods , 47M53 (2006).
113 Oral-21
Adaptive Optics Temporal Focusing-based Multiphoton Excitation Microscopy
Chia-Yuan Chang,1 Yvonne Yuling Hu,2 and Shean-Jen Chen1,2,3,* # $ %' * ' + - * /0# * 2 ' + - * /0# * 2 3 4 ' + - * /0# * 2
Abstract: To compensate spatial or temporal profile distortions, an adaptive optics system (AOS) was integrated into a developed temporal focusing-based multiphoton excitation microscope. With the AOS correction, not only is the axial excitation symmetrically refocused, but the axial resolution with full two-photon excited fluorescence (TPEF) intensity is also maintained. Herein, the contrast of the TPEF image of a R6G-doped PMMA thin film is enhanced along with a 3.7-fold increase in intensity. Furthermore, the TPEF image qualities of fluorescent microbeads sealed in agarose gel and biotissues at different depths are improved.
1. Introduction An adaptive optics system (AOS)1,2 has been integrated into a temporal focusing-based multiphoton microscope3,4 for axially-resolved optical imaging. The AOS uses a 64-element DM as the wavefront corrector, and employs a hill-climbing algorithm to compute an appropriate control signal to drive the deformable (DM) such that the effects of optical aberrations and specimen-induced temporal distortions are reduced. Experimental results show that a developed temporal focusing-based multiphoton microscope with AOS not only recovers the axial resolution but also refocuses the axial excitation. In addition, the TPEF intensity of an R6G-doped PMMA thin film is increased by 3.7-fold5. Contrast enhancements of fluorescent microbeads in agarose gel and biotissues at different sectioning depths can clearly be also observed.
2. Experimental results and discussions Figure 1(a) shows the TPEF image at a depth of = -19 )m ( = 0 )m set as the interface between the cover slip and the specimen) before AOS correction. The excitation efficiency decreased due to the distorted temporal profile; however, as Fig. 1(b) illustrates, image intensity is increased after AOS correction. Figure 1(c) shows the TPEF intensity profiles of the red dashed line of Figs. 1(a) & 1(b), and demonstrates intensity enhancements of 2.1-fold, 2.0-fold, and 2.1-fold for three main peaks from left to right, respectively. Overall, intensity enhancement and better contrast can be achieved via the AOS compensation for fluorescent microbeads at the two different depths. However, the smaller intensity enhancement at greater imaging depths may be due to larger scattering and optical aberrations from the concentrated specimen that could not be fully compensated.
a) b) c) 1 2 3
Fig. 1. TPEF images of 1 )m fluorescent beads in agarose gel at the depth of -19 )m: (a) with distortion and (b) after AOS correction. (c) TPEF intensity profiles of the red dashed line in Figs. 1(a) & 1(b) and the intensity enhancements of 2.1-fold, 2.0-fold, and 2.1-fold for the three main peaks from left to right, respectively. Red line: with distortion; blue line: after AOS compensation.
3. Summary Ultimately, there are three main outcomes of using the AOS compensation: 1) to restore axial resolution and excitation position; 2) to enhance the contrast and intensity of TPEF images of R6G-doped PMMA thin films; and, 3) to improve TPEF image quality of fluorescent microbeads sealed in agarose gel at different depths. Therefore, these experimental results demonstrate that the temporal profile distortions in temporal focusing-based multiphoton microscopy can be compensated by the proposed AOS.
[1] C.-Y. Chung , Appl. Opt. 45, 3409-3414 (2006). [2] C.-Y. Chang , Rev. Sci. Instrum. 84, 095112 (2013). [3] L.-C. Cheng , Opt. Express 20, 8939-8948 (2012). [4] L.-C. Cheng , Biomed. Opt. Express 5, 2526-2536 (2014). [5] C.-Y. Chang , Biomed. Opt. Express 5, 1768-1777 (2014).
114 Oral-24
Measuring the Topological Phase Through the Interface States Between Metasurfaces and Photonic Crystals
Qiang Wang1, Meng Xiao2, Hui Liu1, *, Shining Zhu1 and C.T. Chan2 1National Laboratory of solid State Microstructures & Department and Physics, National Center of Microstructures and Quantum Manipulation, Nanjing University 210093, China 2Department of Physics and Institute for Advanced Study, the Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong E-mail address: [email protected]
Abstract: Zak phase labels the topological property of one-dimensional Bloch Bands. Here we propose a scheme and experimentally measure the Zak phase in a photonic system. Using reflection spectrum measurement, we determined the existence of interface states in the gaps, and then obtained the Zak phases. By manipulating the property of the metasurface, we can further tune the excitation frequency and the polarization of the interface state.
Topological invariant plays a more and more important role in modern physics with the discovery of new materials such as topological insulators. The concept of momentum space topology has also been extended to various photonic systems to realize interesting applications [1]. In a one-dimensional (1D) system, the topological invariant can be characterized by the Zak phase [2], a special kind of Berry phase defined along a 1D bulk band. Recently, Xiao et.al, theoretically investigated the relationship between the Zak phases and the surface impendence in 1D PCs [3]. Inspired by this work, here we propose a method and experimentally measure the Zak phases through interface states [4]. The schematic diagram of our system is illustrated in Fig. 1(a), which is composed of a metal film (or metasurface) and a PC. Detail structural is given in Fig. 1(b). In experiment, we fabricated one PC sample according to the design in Fig. 1(b). We measured the reflection spectrum of the sample and the result is shown as the black curve in Fig. 2(a), which matches well with numerical simulation shown as the black curve in Fig. 2(b). The existence of an interface state can be seen from the reflection spectrum which is presented as a dip inside the gap region. In Fig. 2(a), the two sharp dips in gap 3 and gap 4 indicate the existence of interface states, while there is no interface state in band gap 2. The Zak phase of band 2, 3 and 4 can be determined through the interface state. The corresponding results are summarized in Table.ĉ
Fig. 1 (a) Sketch of an interface between a metal Fig. 2 Experimental (a) and numerical (b) film (or metasurface) and a photonic crystal which reflection spectrum of the PC (black line) and the supports interface states. (b) Sketch of the metasurface/PC (red line). The sharp dips of the metasurface/photonic crystal system. The red curve inside the gap frequency regions of the metasurface consists of nano slits etched on a PC represent interface states between the silver sliver film. film and the PC.
Gap 2 Zak phase of Band 3 Gap 3 Zak phase of Band 4 Gap 4 A-S S-A S-A 0 {,0} {0, } {0, } TABLEĉThe symmetry of band edge states, the reflection phase range of band gaps and the Zak phases of bulk bands. The yellow (blue) region represents the existence (the absence) of an interface state inside this gap.
[1] L. Lu, J. D. Joannopoulos, and M. Soljaclc, Nat. Photonics 8, 821 (2014) [2] J. Zak, Phys. Rev. Lett. 62, 2747 (1989) [3] M. Xiao, Z. Q. Zhang, and C. T. Chan, Phys. Rev. X. 4, 130 (2014) [4] Q. Wang, M. Xiao, H. Liu, S. N. Zhu, C. T. Chan, Phys. Rev. B 93, 041415(R) (2016)
115
THU-PL1
Session: THU-PL1
Date: March 24 (Thursday) Time: 08:15-09:00 Session Chair: . R ` ? 1 0 7 ? 1 Room: Plenary Session
Prof. Lihong Wang
Gene K. Beare Distinguished Professor Washington University in St. Louis, USA (In transition to Caltech)
Redefining the Spatiotemporal Limits of Optical Imaging: March 24, 2016 Photoacoustic Tomography, Wavefront Engineering, 08:15-09:00 and Compressed Ultrafast Photography International Conference Hall (4F)
Biography for Lihong Wang
Lihong Wang holds the Gene K. Beare Distinguished Professorship of Biomedical Engineering at Washington University in St. Louis. His book entitled “Biomedical Optics: Principles and Imaging,” one of the first textbooks in the field, won the 2010 Joseph W. Goodman Book Writing Award. He edited the first book on photoacoustic tomography. Professor Wang has published 425 peer- reviewed journal articles and delivered 420 keynote, plenary, or invited talks. His Google Scholar h-index and citations have reached 99 and over 38,000, respectively. He is the Editor-in-Chief of the Journal of Biomedical Optics. He chairs the annual conference on Photons plus Ultrasound. He received NIH’s FIRST, NSF’s CAREER, NIH Director’s Pioneer, and NIH Director’s Transformative Research awards. He also received the OSA C.E.K. Mees Medal, IEEE Technical Achievement Award, IEEE Biomedical Engineering Award, SPIE Britton Chance Biomedical Optics Award, and Senior Prize of the International Photoacoustic and Photothermal Association for “seminal contributions to photoacoustic tomography and Monte Carlo modeling of photon transport in biological tissues.” An honorary doctorate was conferred on him by Lund University, Sweden. His lab is transitioning to Caltech but plans to continue his collaborations with the medical school of Washington University.
118 PL-9
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Lihong V. Wang Optical Imaging Lab, Dept. of Biomedical Engineering, Washington University in St. Louis, USA E-mail address: [email protected]
Photoacoustic tomography has been developed for in vivo functional, metabolic, molecular, and histologic imaging by physically combining optical and ultrasonic waves. Broad applications include early- cancer detection and brain imaging. High-resolution optical imaging—such as confocal microscopy, two- N [ diffusion limit (~1 mm in the skin) of the surface of scattering tissue. By synergistically combining light and sound, photoacoustic tomography provides deep penetration at high ultrasonic resolution and high optical contrast. In photoacoustic computed tomography, a pulsed broad laser beam illuminates the biological tissue to generate a small but rapid temperature rise, which leads to emission of ultrasonic waves due to thermoelastic expansion. The unscattered pulsed ultrasonic waves are then detected by ultrasonic transducers. High- resolution tomographic images of optical contrast are then formed through image reconstruction. Endogenous optical contrast can be used to quantify the concentration of total hemoglobin, the oxygen saturation of hemoglobin, and the concentration of melanin. Exogenous optical contrast can be used to provide molecular imaging and reporter gene imaging as well as glucose-uptake imaging. In photoacoustic microscopy, a pulsed laser beam is delivered into the biological tissue to generate ultrasonic waves, which are then detected with a focused ultrasonic transducer to form a depth resolved 1D image. Raster scanning yields 3D high-resolution tomographic images. Super-depths beyond the optical diffusion limit have been reached with high spatial resolution. The following image of a mouse brain was acquired in vivo with intact skull using optical-resolution photoacoustic microscopy. The annual conference on photoacoustic tomography has become the largest in SPIE’s 20,000-attendee Photonics West since 2010. Wavefront engineering and compressed ultrafast photography will be touched upon.
; < 1. Nature Biotechnology 21, 803 (2003). 2. PRL 92, 033902 (2004). 3. PRL 96, 163902 (2006). 4. Nature Biotechnology 24, 848 (2006). 5. Nature Protocols 2, 797 (2007). 6. PRL 99, 184501 (2007). 7. Nature Photonics 3, 503 (2009). 8. Nature Materials 8, 935 (2009). 9. Nature Photonics 5, 154 (2011). 10. Nature Materials 10, 324 (2011). 11. Nature Photonics 5, 154 (2011). 12. Science 335, 1458 (2012). 13. Nature Medicine 18, 1297 (2012). 14. PNAS 110, 5759 (2013). 15. PRL 111, 204301 (2013). 19. Nature 516, 74 (2014). 16. PNAS 111, 21 (2014). 20. Nature Photonics 8, 931 (2014). 17. PRL 112, 014302 (2014). 21. Nature Photonics 9, 126 (2015). 18. PRL 113, 174301 (2014). 22. Nature Communications 6, 5904 (2015).
119
THU-IC-S1
Session: THU-IC-S1
Date: March 24 (Thursday) Time: 09:10-10:10 Session Chair: = @ 1 ? @7 ? . 7 ] ] ` ? 1 0 7 ? 1 Room: Invited talk
Prof. Na Liu
University of Heidelberg, Germany
March 24, 2016 Plasmonic walkers on DNA Origami 09:10-09:40 International Conference Hall (4F)
Biography for Na Liu
Laura Na Liu is Professor at the Kirchhoff Institute of Physics at the University of Heidelberg. She received her Ph. D in Physics from the group of Prof. Harald Giessen at the University of Stuttgart in 2009, working on 3D complex plasmonics at optical frequencies. In 2010, she joined the group of Prof. A. Paul Alivisatos as postdoctoral fellow at the University of California, Berkeley. From 2011 until 2012, she was working in the group of Prof. Naomi Halas at Rice University as Texas Instruments visiting professor. At the end of 2012, she obtained a Sofja Kovalevskaja Award from the Alexander von Humboldt Foundation and became an independent group leader at the Max- Planck Institute for Intelligent Systems.
The research of Laura Na Liu is multi-disciplinary. She works at the interface between nanoplasmonics, biology, and chemistry. Her group focuses on developing sophisticated and smart plasmonic nanostructures for answering structural biology questions as well as catalytic chemistry questions in local environments. She is an associate editor of Science Advances.
122 IN-21
Plasmonic walkers on DNA Origami
Na Liu Kirchhoff-Institute for Applied Physics, University of Heidelberg, Germany, and Max-Planck-Institute for Intelligent Systems, Heisenbergstrasse 3, Stuttgart, Germany E-mail address: [email protected]
Abstract: We demonstrate an active plasmonic system, in which a plasmonic nanorod can execute directional, progressive and reverse nanoscale walking on two or three-dimensional DNA origami. Such a walker comprises an anisotropic gold nanorod as its ‘body’ and discrete DNA strands as its ‘feet’.
In nano-optics, a formidable challenge remains in precise transport of a single optical nano-object along a programmed and routed path toward a predefined destination. Molecular motors in living cells that can walk directionally along microtubules have been the inspiration for realizing artificial molecular walkers. Here we demonstrate an active plasmonic system, in which a plasmonic nanorod can execute directional, progressive and reverse nanoscale walking on two or three-dimensional DNA origami. Such a walker comprises an anisotropic gold nanorod as its ‘body’ and discrete DNA strands as its ‘feet’. Specifically, our walker carries optical information and can in situ optically report its own walking directions and consecutive steps at nanometer accuracy, through dynamic coupling to a plasmonic stator immobilized along its walking track. Our concept will enable a variety of smart nanophotonic platforms for studying dynamic light–matter interaction, which requires controlled motion at the nanoscale well below the optical diffraction limit.[1]
Figure 1. Schematic of a plasmonic walker.
[1] C. Zhou, X. Duan, and N. Liu, Nature Communications 6, 8102 (2015).
123 Invited talk
Prof. Minghui Hong
National University of Singapore, Singapore
Sub-diffraction Limit Imaging by Supercritical March 24, 2016 09:40-10:10 Lens with Ultra-long Working Distance International Conference Hall (4F)
Biography for Minghui Hong
Prof. Hong Minghui specializes in laser microprocessing & nanofabrication, optical engineering and applications. He has co-authored 10 book chapters, 24 patents granted, and 350+ scientific papers in Nature, Chemical Reviews, Nature Nanotechnology, Advanced Materials, Nature Communications, Light: Science and Applications etc. and 50+ plenary/keynote/ invited talks in international conferences. He is a member of organizing committees for Laser Precision Micromachining International Conference (2001~2015), International Symposium of Functional Materials (2005, 2007 and 2014), Chair of International Workshop of Plasmonics and Applications in Nanotechnologies (2006), Chair of Conference on Laser Ablation (2009) and Chair of Asia-Pacific Near-field Optics Conference (2013). Prof. Hong is invited to serve as an Editorial Board Member of Scientific Reports, Associate Editor of Science China, International Journal of Optomechatronics, and Editor of Laser Micro/nanoengineering. Prof. Hong is Fellow of Optical Society of America (OSA), Fellow of International Society for Optics and Photonics (SPIE), and Fellow of International Academy of Photonics and Laser Engineering (IAPLE).
124 IN-24
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Breaking the diffraction limit to realize super-resolution optical imaging in completely non- invasive manners is in an urgent need for many optical detection processes, especially for non- biological samples which cannot be labelled properly. Planar metalens, as a substitution of traditional sphere lens, has been proposed to focus light into a sub-diffraction-limit spot for super- resolution imaging beyond the evanescent region. However, most reported metalenses have very short working distances, imposing a formidable difficulty for practical applications1,2. The inevitable strong sidelobe seriously affects the imaging process1. Here we propose and experimentally demonstrate a concept of supercritical lens (SCL), which consists of an optimized binary amplitude type zone plate to modulate the illumination light in construction interference3,4. A sub-wavelength focal spot in 0.38 (/NA without the strong sidelobe is achieved by our supercritical lens. Such a supercritical lens can stably keep a lateral subwavelength width along the needle-like focal region without losing the focusing resolutions. The focusing ability has been demonstrated under the illumination of azimuthally polarized beam with vertical phase at 633nm. By implementing the 405 nm SCL, we experimentally demonstrated sub-100nm resolution imaging in air with 150 ( (60 3m) working distance which is one order larger than the previous published result. The imaging process is purely physical and real time captured, do not need any mathematical post- processing to obtain the imaging results. Large and complicated sub-wavelength pattern is successfully demonstrated, attributed to the high scanning speed of our system and the long depth of focus (DOF) of the SCL stands for the enormous pixels and parallelism tolerance. Equally important, such lens with those advantages are fabricated by a laser pattern generator with high efficiency rather than FIB or EBL, since the smallest feature size of this SCL is in micrometers scale, which makes the large size patterns and mass production possible.
; < / 1 Rogers, E. T. A super-oscillatory lens optical microscope for subwavelength imaging. ##, 432-435 (2012). 2 Zheng, X. Highly efficient and ultra-broadband graphene oxide ultrathin lenses with three- dimensional subwavelength focusing. =, 8433 (2015). 3 Huang, K. Optimization-free superoscillatory lens using phase and amplitude masks. S ^, 152-157 (2014). 4 Qin, F. Shaping a Subwavelength Needle with Ultra-long Focal Length by Focusing Azimuthally Polarized Light. S `, 9977 (2015).
125
Session: THU-R1-S1 THU-R1-S1
Date: March 24 (Thursday) Time: 09:10-10:10 Session Chair: R?7 ` 7 ? . 0 7 ] ] R . ` ? 0 7 ? 1 Room: 1st Conference Room (3F) Invited talk
Prof. Paolo Biagioni
Politecnico di Milano, Italy
March 24, 2016 Germanium mid-infrared plasmonics for sensing 09:10-09:40 1st Conference Room (3F)
Biography for Paolo Biagioni
Paolo Biagioni studied at Politecnico di Milano (Italy), where he first got his Degree in Electronic Engineering in 2003 and then his Ph.D. in Physics in 2007 with the dissertation ‘Field enhancement and confinement at optical wavelengths: nonlinear near-field microscopy and resonant metal nanoparticles’ under the supervision of Prof. Lamberto Duò. In 2008 he was awarded a Humboldt Fellowship for Postdoctoral Researchers, which he spent working in the group of Prof. Bert Hecht in Würzburg (Germany), focusing on near-field polarization engineering with optical cross antennas and on the impedance description of plasmonic antenna circuits. He has been Assistant Professor since 2010 and Associate Professor since 2014 at the Physics Department, Politecnico di Milano (Italy). His research interests are in nano-optics and plasmonics. At present his main activities are focused on:
- Linear and nonlinear properties of Au nanoantennas - Mid-infrared plasmonics and sensing with heavily-doped Ge materials - Subwavelength Ge resonators for enhanced light emission at telecom wavelengths - Nanoscale polarization control
He is the coordinator of the FET-Open EU project GEMINI (‘GErmanium Mid-Infrared plasmoNIcs for sensing’).
128 IN-22
Germanium mid-infrared plasmonics for sensing
Leonetta Baldassarre1, Emilie Sakat2, Jacopo Frigerio2, Antonio Samarelli3, Valeria Giliberti1, Giovanni Pellegrini2, Kevin Gallacher3, Marco P. Fischer4, Daniele Brida4, Giovanni Isella2, Douglas J. Paul3, Michele Ortolani1, Paolo Biagioni2 1 Dipartimento di Fisica, Sapienza Università di Roma, Rome, Italy 2 Dipartimento di Fisica e L-NESS, Politecnico di Milano, Milano, Italy 3 School of Engineering, University of Glasgow, Glasgow, United Kingdom 4 Department of Physics and Center for Applied Photonics, University of Konstanz, Konstanz, Germany E-mail address: [email protected]
Abstract: We report on a novel material platform for mid-infrared plasmonics based on heavily-doped Ge epitaxially grown on Si. We describe the realization of mid-infrared resonant antennas and their application to sensing, all-optical devices, and nonlinear optics.
The quest for novel plasmonic materials has been a lively area of research over the last few years. In the mid-infrared (mid-IR) spectral region, in particular, localized plasmon resonances in nanoparticles and nanoantennas hold promise for enhanced IR spectroscopies, with key applications in biology, medicine, and security. In this frame, the development of a CMOS-compatible plasmonic platform in the mid-IR could have disruptive effects for future technologies, allowing for cost-effective sensing devices integrated with electronics [1-2]. We report on the growth, fabrication and optical characterization of heavily-doped Ge antennas integrated on a Si substrate and we exploit them for the sensing of solid-phase and liquid-phase analytes [3-5]. Epitaxial Ge is grown on Si by plasma-enhanced chemical vapor deposition, exploiting phosphorous as the dopant and achieving plasma frequencies above 1000 cm-1. We demonstrate two-wire gap antennas fabricated by electron- beam lithography and reactive ion etching techniques, displaying localized plasmon resonances in the important 8 to 13 3m molecular fingerprint region. We target the sensing of a thin polydimethylsiloxane (PDMS) layer (thickness of about 40 nm) and demonstrate an enhancement of two orders of magnitude in the collected signal, as derived from a comparison with the results of detailed numerical simulations. We also demonstrate real-life application such as the sensing of explosive simulants in the liquid phase, which is of interest for airport security screening. Finally, we use Ge antennas to demonstrate for the first time all-optical doping, ultrafast control of antenna resonances, and plasmon-enhanced third harmonic generation in the mid-infrared.
Fig. 1. A SEM image of the Ge antennas on Si (left panel) and sensing of the 800 cm-1 vibrational line in PDMS (right panel) for polarization parallel (black line) and perpendicular (grey line) to the antenna axis).
Our results represent a first experimental benchmark for group-IV mid-IR plasmonics and confirm that future CMOS sensing platforms could benefit significantly from plasmonic enhancements provided by integrated heavily-doped Ge-based devices. The research leading to these results has received funding from ¥ R } ? ¯¯
[1] R. Soref, Nature Phot. 4, 495-497 (2010). [2] R. Soref, J. Hendrickson, and J.W. Cleary, Opt. Exp. 20, 3814-3824 (2012). [3] L. Baldassarre, E. Sakat, J. Frigerio, A. Samarelli, K. Gallacher, E. Calandrini, G. Isella, D.J. Paul, M. Ortolani, and P. Biagioni, Nano Lett. 15, 7225-7231 (2015). [4] P. Biagioni, J. Frigerio, A. Samarelli, K. Gallacher, L. Baldassarre, E. Sakat, E. Calandrini, R.W. Millar, V. Giliberti, G. Isella, D.J. Paul, and M. Ortolani, J. Nanophot. 9, 093789 (2015). [5] A. Samarelli, J. Frigerio, E. Sakat, L. Baldassarre, K. Gallacher, M. Finazzi, G. Isella, M. Ortolani, P. Biagioni, and D.J. Paul, Thin Solid Films (in press), doi:10.1016/j.tsf.2015.10.005.
129 Invited talk
Prof. Jeongyong Kim
Sungkyunkwan University, Korea
Optical Visualization of Exciton Competitions March 24, 2016 09:40-10:10 in TMD Monolayers 1st Conference Room (3F)
Biography for Jeongyong Kim
Prof. Jeongyong Kim got his BSc and Ph.D in physics at Korea University, Korea in 1993 and at University of Cincinnati, US in 1998, respectively. After working as post-doc and senior researcher in University of Illinois at Urbana-Champaign and ETRI, Korea, he joined the faculty of Physics in Incheon National University, Korea in 2002. In 2013, he moved to Dept. of Energy Science and IBS research center in Sungkyunkwan University (SKKU), Korea and is conducting researches on nano optical studies on 2D transition metal dichalcogenide (TMD) materials including MoS2, WS2 monolayers and heterostructures. His current interests are use of nanoscale spectral imaging to visualize grain boundaries and structural defects and to study the exciton mechanisms present in monolayer TMDs and hetero TMDs. He co-authored ~100 peer-reviewed papers in his career in the areas of nano optics and materials science published in scientific journals including Advanced Materials, Physical Review Letters, ACS Nano and Nanoscale.
130 IN-25
Optical Visualization of Exciton Competitions in TMD Monolayers
Yongjun Lee1,2, Minsu Kim2, Seok Joon Yun1,2, Seki Park1,2, Gang Hee Han2, Young Hee Lee1,2 and Jeongyong Kim1,2* + - / 4 4 6 4 6 778 :7; & F
Abstract: Near-field photoluminescence (PL) images and spectra were obtained from 2D transition-metal dichalcogenide monolayers. Nanoscale resolved PL images and spectra provided critical information on structural defects and interesting exciton mechanisms in these atomic layers, which were not accessible by conventional confocal PL spectroscopy.
Transition metal dichalcogenides (TMDs) monolayers are atomically thin semiconducting layers with visible wavelength emission [1], being actively studied for nanophotonics applications. However, the defects such as grain boundary and other nano-size defects can critically influence the electrical and optical properties of monolayer TMDs grown by chemical vapor deposition (CVD) and the exciton formation in the form of neutral exciton, trion and biexcition, which are unique characteristics of these atomically thin TMD materials, are not fully understood. Therefore, optical investigations that can visualize the nano-size defects and grain boundaries and can investigate the underlying mechanism of exciton participation are in great demand. Although conventional micro or confocal PL imaging has been proved powerful [2], the limited spatial resolution of PL imaging prevents the identification of nano-size structural defects and more in-depth investigation of monolayer TMDs. Here, we present nanoscale PL images and spectra of CVD-grown monolayer MoS2 and WS2 obtained using near-field scanning optical microscope (NSOM) with nanoscale spatial resolution. Our results obtained from polycrystalline MoS2 monolayer suggested that decreased PL on grain boundaries is due to the local physical damage of the MoS2 film rather than due to the presence of localized states [3]. In monolayer WS2, NSOM showed fine structure of nanoscale PL profiles that provide critical information on exciton competition occurring in monolayer WS2.
Fig. 1. Near-field PL images of monolayer MoS2 References
[1] K. F. Mak, C. Lee, J. Hone, J. Shan and T. F. Heinz, "Atomically thin MoS2: a new direct-gap semiconductor" S , 105, 136805 (2010). [2] K. P. Dhakal, D. L. Duong, J. Lee, H. Nam, M. Kim, M. Kan, Y. H. Lee and J. Kim, "Confocal absorption spectral imaging of MoS2: optical transitions depending on the atomic thickness of intrinsic and chemically doped MoS2" 6, 13028 (2014), [3] Y. Lee, S. Park, H. Kim, G. H. Han, Y. H. Lee and J. Kim, "Characterization of the structural defects in CVD-grown monolayer MoS2 using near-field photoluminescence imaging" , 7, 11909 (2015),.
131
Session: THU-R2-S1
Date: March 24 (Thursday) Time: 09:10-10:10 Session Chair: . .R= ` ; 1 0 7 ? 1 THU-R2-S1 . R ` ; 1 0 7 ? 1 Room: 2nd Conference Room (3F) Invited talk
Prof. Junichi Takahara
Osaka University, Japan
Metal-Air-Metal Nanocavity in a Slanted Plasmonic March 24, 2016 09:10-09:40 Nanowire Suspended on a Metal Substrate 2nd Conference Room (3F)
Biography for Junichi Takahara
Education 1990 March, B.S. in Electrical Engineering, Department of Engineering Science, Osaka University 1995 March, Ph.D., Graduate School of Engineering Science, Osaka University
Professional Experience 1992-1995 Research Fellow of the Japan Society for the Promotion of Science 1995-2003 Assistant Professor, Graduate School of Engineering Science, Osaka University 2003-2010 Associate Professor, Graduate School of Engineering Science, Osaka University 2010-present Professor, Photonics Advanced Research Center, Osaka University Graduate School of Engineering, Osaka University
134 IN-23
Metal-Air-Metal Nanocavity in a Slanted Plasmonic Nanowire Suspended on a Metal Substrate
Junichi Takahara Photonics Advanced Research Center, Osaka University Graduate School of Engineering, Osaka University E-mail address: [email protected]
Abstract: We propose and demonstrate a novel metal-air-metal nanocavity by a slanted plasmonic nanowire suspended on a metal substrate. A probe-based pick-and-place method is used by fabricating and placed the nanowire onto the substrate. The optical scattering spectra from the nanowire show gap plasmon resonance which is attributed to Fabry-Perot interference of surface plasmon inside the gap. From the numerical simulations, we estimate gap distance of 5-66nm, which means we are able to realize the cavity size below 10nm.
Few-nanometer gaps between metals produce large field enhancements and thus are widely used to design nanostructures for practical applications, such as surface-enhanced spectroscopy etc. For the largest field enhancements, it is critical to realize smooth and precisely dimensioned metallic nanogaps to enable strong gap plasmon resonances. In recent years, various fabrication approaches have been used to make metallic nanogaps. Because of the accuracy of processes and the surface roughness of deposited metal layers, the quality of the gap plasmon resonances is fundamentally limited. A notable exception is the use of dielectric layer to form a metal-insulator-metal (MIM) nanocavity [1] or a film coupled metallic nanoparticle [2], which provides a smooth metallic nanogap as well as the precise control of the gap size below 10 nm. However, the spacing dielectric layer prevents access to the enhanced field spot in the gap, making them difficult to use in surface-enhanced spectroscopy and in sensing applications. In this paper, we propose and demonstrate a novel metal-air-metal (MAM) nanocavity by using a slanted gold nanowire suspended on a gold substrate [3]. The MAM structure is shown in Fig. 1. A probe-based pick- and-place method was used by fabricating and manipulating the nanowire and focused ion beam (FIB) was used by fixing it onto the substrate. We obtained dark field images under white light illumination and measured the scattering spectra from each position of the nanowire. The images show gradual color change from red to green due to the gap distance change and each spectra shows gap plasmon resonance which is attributed to Fabry-Perot interference of surface plasmon inside the gap [4,5]. From the numerical simulations, we estimated gap distance of 5-66nm, which indicate that we are able to realize the cavity size below 10nm.
[1] H. T. Miyazaki, Y. Kurokawa, Phys. Rev. Lett. 96, 097401 (2006). [2] W. R.Holland, D. G. Hall, Phys. Rev. Lett. 52 %1044 (1984). [3] M. Miyata, A. Holsteen, Y. Nagasaki, M. L. Brongersma, and J.Takahara, Nano Lett. 15, 5609-5616 (2015). [4] S. I. Bozhevolnyi, T. Søndergaard, Opt. Express 15 ?% ££ (2007). [5] E. S.Barnard, J. S.White, A.Chandran, M. L.Brongersma, Opt. Express 16 ?¯ % ?¯ £ (2008).
Figure 1. A slanted gold nanowire suspended on a gold substrate: (a) Schematic cross sectional view and (b) side view of the nanowire. (c) SEM image. Metal-air-metal nanocavity is formed, where the gap distance g(x)=0~50nm.
135 Invited talk
Dr. Feng Qiu
Kyushu University, Japan
March 24, 2016 Hybrid Electro-optic Polymer Modulators 09:40-10:10 2nd Conference Room (3F)
Biography for Feng Qiu
Feng Qiu, born in November 1982, currently is working at Kyushu University, Japan. He received the degrees of Master of Science and Doctor of Science from Jilin University in 2008 and Kochi University of Technology in 2011, respectively. After he finished his doctoral dissertation he worked at Kyushu University.
His research interests include optical waveguides, electro-optic modulators, microwave photonics, etc. Particularly, he is very active in the scientific community related to electro- optic waveguide modulators in organic polymer. He has more than 50 papers published in peer- reviewed journals. He receives a number of awards and honors from diverse organizations, such as the Ministry of Education, China, and Japan Society for the Promotion of Science, for his contribution on optics and photonics.
136 IN-26
Hybrid Electro-optic Polymer Modulators
Feng Qiu*, and Shiyoshi Yokoyama < +
Abstract: Inside optical transmission systems, electro-optic (EO) modulators are one of the vital building blocks. Among different types of materials used to construct modulators, EO polymer can offer intrinsic advantages such as a large EO coefficient (r33), high bandwidth, low dielectric constant and loss, and excellent compatibility with other materials and substrates. Here, we present several novel designed modulators based on the EO polymer / titanium dioxide hybrid structure
1. Hybrid electro-optic modulators Effective electro-optic (EO) modulators are desirable for a number of applications. In this work, we will introduce three kinds of EO polymer / titanium dioxide (TiO2) hybrid waveguide modulators: (1) EO polymer covered TiO2 nano-line; (2) Compact ring resonators; (3) EO polymer filled slots. A TiO2 strip line of 300 nm-thick and 300 nm-wide was fabricated on the SiO2/Si substrate, and subsequently the EO polymer was spin-coated as the cladding layer (Fig.1). By using the TiO2 nano-line as the core, the confinement factor in the EO polymer is optimized for the highest EO activity. The coplanar electrodes were designed to obtain the highest poling efficiency and minimize the absorption loss. We measured an in-device EO coefficient at 1550 nm, modulator driving voltage, and optical loss. We used the high grass transition temperature (U ) EO polymer to test the temporal stability of the EO activity at 85°C for 500 hours [1]. An EO modulator using a TiO2 slot hybrid waveguide has also been designed and fabricated (Fig. 2). Optical mode calculations revealed that the mode was primarily confined within the slots when using a double-slot configuration, thus achieving a high EO activity experimentally. The TiO2 slots also acted as an important barrier to induce an enhanced DC field during the poling of the EO polymer and the driving of the EO modulator. The hybrid phase modulator exhibited a driving voltage (V4) of 1.6 V at 1550 nm, which can be further reduced to 0.8V in a 1cm-long push-pull Mach–Zehnder interferometer structure. The modulator demonstrated a low propagation loss of 5 dB/cm and a relatively high end-fire coupling efficiency [2]. At last, a ring modulator has been fabricated in the titanium dioxide (TiO2) core and EO polymer cladding waveguide structure (Fig. 3). We have utilized a 250nm thick TiO2 core to minimize the ring radius down to 100 )m, to avoid using the top-cladding between EO polymer and electrode, and to improve the poling efficiency. The resonance obtained by the ring modulator was observed to shift by 0.02 nm/V due to the enhanced in-device EO coefficient of 105 pm/V [3].
2. Figures and tables
ġ ġ Fig. 1 Nano-line waveguide modulator Fig. 2 Slot waveguide modulator Fig. 3 Ring resonator modulator
3. References [1] F. Qiu, A. M. Spring, D. Maeda, M. Ozawa, K. Odoi, I. Aoki, A. Otomo, and S. Yokoyama, “A Straightforward Electro-optic Polymer Covered Titanium Dioxide Strip Line Modulator with a Low Driving Voltage”, Appl. Phys. Lett. 105, 073305 (2014). [2] F. Qiu, A. M. Spring, D. Maeda, M. Ozawa, K. Odoi, A. Otomo, I. Aoki, and S. Yokoyama, “A hybrid electro-optic polymer and TiO2 double-slot waveguide modulator,” Sci. Rep. 5, 8561 (2015). [3] F. Qiu, A. M. Spring, F. Yu, I. Aoki, A. Otomo, and S. Yokoyama, “Electro-Optic Polymer / Titanium Dioxide Hybrid Core Ring Resonator Modulators”, Laser Photonics Rev. 7, 87 (2013).
137
Session: THU-IC-S2
Date: March 24 (Thursday) Time: 10:30-12:00 Session Chair: ` 0 7 7 . .R ` ? 1 0 7 ? 1 Room: THU-IC-S2 Invited talk
Prof. Yoshimasa Kawata
Shizuoka University, Japan
Nano-imaging of live cells with electron beam March 24, 2016 10:30-11:00 excitation assisted microscope International Conference Hall (4F)
Biography for Yoshimasa Kawata
Professor Yoshimasa Kawata completed his doctorate in applied physics with the theoretical and experimental studies on nonlinear optical effect in photorefractive crystals at Osaka University in 1992. He joined the Department of Applied Physics at Osaka University as an assistant professor in 1992. He started the research on the applications of optical microscopy to the high density optical data storage. He is a pioneer of multilayered optical data storage and he proposed to use confocal optical microscope to readout system of optical data storage system. During the period of the assistant professor, he visited and worked at Bell Laboratories as a visiting researcher supported by Japan Society for the Promotion of Science (JSPS). He moved to Shizuoka University as an associate professor in 1997 and was promoted to full professor in 2005. His works are involved in near-field optics, multiphoton process, femtosecond photonics, laser manipulation, bio-photonics, etc. He was selected as Distinguished Researcher of Shizuoka University in 2011. Professor Kawata is currently president of Society of Laser Microscopy and the head-editor of the Journal of Optical Society of Japan. He is committee member of many international societies and journals, such as the chair of ISOM (International Symposium on Optical Memory) organizing committee. He was awarded OSA Fellow in 2013. Currenty he is Vice Dean of Faculty of Engineering, Shizuoka University.
140 IN-27
Nano-imaging of live cells with electron beam excitation assisted microscope
Yoshimasa Kawata, Masahiro Fukuta, and Wataru Inami S E C " '$ E
Abstract: We have developed electron beam excitation assisted (EXA) optical microscope, and demonstrated its resolution higher than 50 nm. In the microscope, a light source in a few nanometers size is excited by focused electron beam in a luminescent film. The microscope makes it possible to observe dynamic behavior of living biological specimens in various surroundings, such as air or liquids. Scan speed of the nanometric light source is faster than that in conventional near-field scanning optical microscopes.
1. Introduction Optical microscopes are effective tools for cellular function analysis because biological cells can be observed non-destructively and non-invasively in the living state in either water or atmosphere condition. In order to analyze the functions of proteins, granules, and organelles, a higher resolution imaging technique is strongly required because the spatial resolution of a conventional optical microscope is limited to 200 nm by the diffraction limit of light. Here, we demonstrate the dynamic imaging of a label-free living cell at a high spatial resolution by using a nano-scale CL light source [1-4]. We successfully observe the dynamics of the nucleus and cellular granules by scanning the nano-scale light source. It is effective for cellular function analysis and significant in the dynamic analysis of biological cells [1-4].
2. Electron beam excitation assisted microscope Figure 1(a) shows schematic diagram of the proposed EXA microscope [1-6]. An electron beam is focused on a luminescent film. A specimen is put on the luminescent film directly. The inset in Fig. 1(a) shows magnified image of the luminescent film and the specimen. Nanometric light source is excited in the luminescent film by the focused electron beam. The nanometric light source illuminates the specimen, and the scattered or transmitted radiation is detected with a photomultiplier tube (PMT). The light source is scanned by scanning of the focused electron beam in order to construct on image. Figure 1(b) shows a luminescence image of the cells acquired with the D-EXA microscope, and Fig. 1(c) shows a phase contrast microscope image. Cells were observed in culture solution without any treatments, such as fixation and drying. The shape of each cell was clearly recognized and some bright spots were observed in cells.
Fig. 1: (a) Optical setup of EXA microscpe, and observation results of of living MARCO-expressing CHO cells with (b) EXA microscope and (c) phase contrast microscope. References [1] M. Fukuta, S. Kanamori, T. Furukawa, Y. Nawa, W. Inami, S. Lin, Y. Kawata and S. Terakawa, -imaging of label-free living cells using electron beam excitation-assisted optical microscope 0 ± 5, p. 16068 (2015). [2] Y. Nawa, W. Inami, S. Lin, Y. Kawata, and S. Terakawa, -resolution, label-free imaging of living cells with direct electron-beam-excitation-assisted optical microscopy Optics Express, Vol. 23, pp. 14561-14568 (2015). [3] Y. Masuda, Y. Nawa, W. Inami, Y. Kawata, Carboxylic monolayer formation for observation of intracellular structures in HeLa cells with direct electron beam excitation-assisted fluorescence microscopy Biomedical Optics Express, Vol. 6, No. 8, pp. 3128-3133, (2015). [4] W. Inami, K. Nakajima, A. Miyakawa, Y. Kawata, Electron beam excitation assisted optical microscope with ultra-high resolution Optics Express, Vol. 18, No. 12, pp. 12897-12902, (2010).
141 Oral-25
Fast volumetric imaging and patterned illumination via DMD-based temporal focusing multiphoton microscopy
Chia-Yuan Chang,1,2 Yvonne Yuling Hu,3 Chun-Yu Lin,1,2 and Shean-Jen Chen1,2,4,* 1Department of Engineering Science, National Cheng Kung University, Tainan 701, Taiwan 2Center for Micro/Nano Science and Technology, National Cheng Kung University, Tainan 701, Taiwan 3Department of Photonics, National Cheng Kung University, Tainan 701, Taiwan 4Advanced Optoelectronic Technology Center, National Cheng Kung University, Tainan 701, Taiwan *[email protected]
Abstract: Temporal focusing-based excited multiphoton microscopy has advantages of natural axial optical sectioning and fast wide-field multiphoton imaging. A fast volumetric imaging technique could be achieved by synchronizing the fast EMCCD acquisition with continuous driven piezo focusing stage. We have demonstrated a stable 30 volume/sec imaging rate to monitor ) fluorescent bead Brownian motion. Furthermore, with single DMD integration, we simultaneously have temporal focusing excitation and fast pattern illumination. The dynamic structural excitation with volumetric imaging is at 15 volume/sec and HiLo technique is applied for background noise rejection.
1. Introduction Based on the temporal focusing wide-field excitation, high speed axial scanning mechanism is developed for the requirement of fast volumetric imaging [1]. In order to push the EMCCD frame rate to the limit, the acquisition is running continuously and is not able to be triggered whenever the z position is reached. We synchronize the EMCCD acquisition with piezo focusing stage to perform fast volumetric imaging. Therefore, we adopt EMCCD-generated clock as synchronization clock to drive the piezo focusing stage with modified sinusoidal waveform based on the FPGA. The 3D ) fluorescent beads Brownian motion is shown at 30 volume/sec. Furthermore, the DMD is synchronized with the volumetric imaging system to demonstrate fast axial scanning and pattering. We have demonstrate the fast HiLo with structural illumination to suppress the background scattering noise [2]. 2. tracking and fast optical patterning integration The high volumetric rate scanning capability would be able to directly monitor the small particle Brownian motion in 3D. The random moving process in solution due to particle collision and thermal perturbation could be described by diffusion equation. The theoretical rms displacement is 313 nm which is less than the bead radius. Hence, the volumetric imaging ra ) Brownian motion without artifactitious aliasing error theoretically. A single fluorescent bead is traced by its center of gravity and the trajectory with time is shown in Fig. 1 (a). The DMD is not only used as diffraction element, but also generating pattern for structural illumination [3]. The volumetric patterning illumination is at 15 volume/sec. In the experiment, we apply sinusoidal and uniform excitation pattern respectively to DMD during volumetric imaging for HiLo reconstruction. Fig. 1 (b) shows the comparison of raw fluorescence image and HiLo image. The scattering background noise is obviously eliminated.
30 0.5
0.4 20 0.3 m 10 0.2 0.1
0 (a.u.) Normalized Intensity 0 0 5 10 15 20 25 0 5 10 15 20 25 30 35 40 Time (sec) (m) (a) (b) Fig. 1 (a) The trajectory of 1 ) t bead. (b) Contrast improvement after HiLo technique. 3. Conclusions A temporal focusing-based multiphoton microscope is synchronized with the fast piezo focusing stage 22 } } ² ) Brownian motion could be observed directly without artifactitious aliasing error. The 3D real time functional excitation and imaging technique could be realized and has potential for neuron network study, high throughput microfabrication, and dynamic structural illumination techniques that could reject the background noise and improve image contrast. 4. References [1] L.-C. Cheng et al., Opt. Express 20(8), 8939M8948 (2012). [2] J. Mertz et al., J. Biomed. Opt. 15(1), 016027 (2010). [3] J.-N. Yih et al., Opt. Lett. 39(11), 3134M3137 (2014).
142 Oral-28
Lasing characteristic of ZnO plasmonic laser with various gap layer thickness
Yu-Hsun Chou1,2, Bo-Tsun Chou3, Sheng-Di Lin3, Tzy-Rong Lin4,Chien-Chung Lin1 and Tien-Chang Lu2* U U U U C U " = + > 6 = < < 6 6
Abstract: In this letter, we report on the effect of different gap layer thickness of the ZnO plasmonic laser. By controlling the thickness of the gap layer, the dispersion of the device can be manipulate and resulting different group index.
1. Introduction During the past decade, utilize metal into optics device has become a main strategy to overcome the diffraction limit. For laser devices, exploiting metal in optical cavity can generate two types of effect to minimize mode volume [1]. The nanometer scale skin depth force the mode to exist in the small metallic cavity or applying surface plasmon to shrink down the mode below diffraction limit. In 2003, the first concept of SPP nanolaser was introduced by Bergman and Stockman and has demonstrated by Oulton et al. in 2009 in a CdS-based nanowire plasmonic nanolasers with semiconductor-insulator-metal (SIM) structure to minimize metal loss [2,3]. The mechanism of surface plasmon nanolaser provides a new way to overcome the diffraction limit of light. Surface plasmon nanolasers own the benefit of low energy consumption, very small mode volume, high Purcell factor, fast modulation and so on [1-4]. Here we theoretically and experimentally demonstrate the laser action of surface plasmon nanolaser by using the SIM approach and investigate the characteristic of samples with different SiO2 gap layer thickness between ZnO nanowire and silver film. 2. Result and discussion The measured emission spectra at different pumping density are shown in Fig.1a. which shows a clear evidence of lasing operation.Fig.1b and Fig.1c shows The group indices range from 33 to 36 in Fig.1e were estimated from the mode spacing of the spectrum, which were show in Fig.1b.For sample with thicker spacer (not shown), the calculated dispersion curve near the UV region has a smaller dispersion, which will resulting smaller group index. In another hand, sample with thinner gap layer will strongly affect by the surface plasmon effect provide by Ag and shows a larger dispersion at UV region with larger group index.
Figure 1. Lasing characteristics of the device with 12 nm spacer thickness at 77 K. a Measured spectra at different laser pumping power density from 115 MW/cm2 to 535 MW/cm2. b Peak positions extracted from the emission spectra in a at the laser pumping power density from low to high. c The group index estimated 2 by ng ³ ( ² (1 3. References [1] M. P. Nezhad, A. Simic, O. Bondarenko, B. Slutsky, A. Mizrahi, L. A. Feng, V. Lomakin, and Y. Fainman, "Room-temperature subwavelength metallic-dielectric lasers," Nature Photonics,. 4, pp. 395-399 (2010). [2] Bergman, D. J. & Stockman, M. I. Phys. Rev. Lett. 90, 027402 (2003). [3] R. F. Oulton, V. J. Sorger, T. Zentgraf, R. M. Ma, C. Gladden, L. Dai, et al., "Plasmon lasers at deep subwavelength scale," Nature, 461, 629-32 (2009). [4] Y. J. Lu, J. Kim, H. Y. Chen, C. Wu, N. Dabidian, C. E. Sanders , "Plasmonic nanolaser using epitaxially grown silver film," Science 337, 450-3 (2012).
143 Oral-31
Optimized enhancement photoluminescence of monolayer MoS2 by covering the densities of plasmonic Au nanonrods
Chiao-Yun Chang1, Hsiang-Ting Lin1,2, Kevin C. J. Lee1, Yi-Huan Chen1, Hsiang-Yu Lin1,2 , Min- Hsiung Shih1,2,6,*, Kung-Hwa Wei3, Lain-Jong Li4 and Chien-Wen Chang5 1 Research Center of Applied Sciences (RCAS), Academia Sinica, Taipei, 11529, Taiwan 2 Department of Photonics, National Chiao Tung University (NCTU), Hsinchu, 30010, Taiwan 3 Department of Materials Science & Engineering National Chiao Tung University Hsinchu, 30010, Taiwan 4 Physical Science and Engineering Division, King Abdullah University of Science and Technology (KAUST), Thuwal, 23955-6900, Kingdom of Saudi Arabia 5 Department of Biomedical Engineering and Environmental Sciences, National Tsing Hua University (NTHU), Hsinchu, 30013, Taiwan 6Department of Photonics, National Sun Yat-sen University, Kaohsiung, 804, Taiwan E-mail address: [email protected]
Abstract: We have optimized the plasmonic enhancement photoluminescence (PL) of monolayer MoS2 to improve the weak light emission of two-dimensional materials by varying Au nanorods (NRs) densities. The better spatial and spectral coupling between the MoS2 emission and localized surface plasmonic resonance (LSPR) of Au NRs beneficially enhanced the internal quantum efficiency of MoS2. On the other hand, the shielding effect of Au NRs diminish to dominate the light extraction efficiency with increasing the Au NRs densities. Thus, the optimal PL intensity of monolayer MoS2 is achieved the 6.1 fold enhancement at the Au NRs density of 40 )m-2.
Recently the single layer of the two-dimensional transition metal dichalcogenides (2D-TMDCs) have been attracted, such as molybdenum disulfide (MoS2) and tungsten diselenide (WSe2)[1]. The excellently properties of MoS2 and WSe2 includes the direct bandgap, ulra-thin and flexible to realize the flexible photonic and electronic [2]. However, the thickness of 0.7 nm monolayer MoS2 exhibits the low internal quantum efficiency. In this study, we investigate to enhance photoluminescence (PL) emission in monolayer MoS2 by different densities of plasmonic Au nanorod (NRs). The diameter of 25 nm and length of 57 nm Au NRs in toluene solvent are placed on the sapphire substrate by spin coating. Fig. 1 (a) shows the absorption spectrum of the Au NRs, which mainly covers the wavelength from 600 to 800 nm. The red curve is the PL spectrum of the monolayer MoS2 with an emission peak approximately 670 nm. Moreover, the longitudinal LSPR mode of the Au NRs also exists in the interface of Au NRs and the MoS2 nanosheet on the sapphire substrate as shown in the inset Fig. 1(b). It has the better spectral overlapping between the MoS2 emission and localized surface plasmonic resonance (LSPR) wave of Au NRs. Fig. 1(b) shows the PL enhancement factor -2 of monolayer MoS2 with different Au NRs densities form 0 to 120 )m . The spectral and spatial coupling between the Au NRs LSPR and the monolayer MoS2 light emission cause to achieve the strongly PL enchantmentį But it is worth to note that the PL enchantment factor become small at the Au NRs densities of -2 more than 40 )m . The shielding effect of Au NRs influences the light extraction efficiency to dominate light emission efficiency above the higher Au NRs densities. Thus, the optimal PL intensity of monolayer MoS2 is -2 achieved 6.1 fold enhancement at the Au NRs density of 40 )m .
Fig.1 (a) The absorption spectrum of Au NRs on the sapphire substrate and the PL spectrum of the monolayer MoS2 on the sapphire substrate. The inset figure is the schematic diagram of MoS2 with Au NRs on sapphire substrate and the near-field optical intensity map for Au NRs on the monolayer MoS2. (b) The PL enhancement factor of monolayer MoS2 as a function of Au NRs densities. The inset figure is the PL -2 spectrum of the monolayer MoS2 with the coverage of Au NRs at the densities of 0, 40 and 120 )m . References [1] P. Tonndorf, R. Schmidt, P. Böttger, X. Zhang, J. Börner, A. Liebig, Opt. Express 21, 4908-4916 (2013). [2] Q. H. Wang, K. Kalantar-Zadeh, A. Kis, J. N. Coleman, and M. S. Strano, Nature Nanotech. 7, 699-712 (2012).
144 Session: THU-R1-S2
Date: March 24 (Thursday) Time: 10:30-12:00 Session Chair: = 7 . .R . % ? 1 Room: 1st Conference Room (3F) THU-R1-S2 Invited talk
Prof. Ken-Tye Yong
Nanyang Technological University, Singapore
March 24, 2016 Plasmonic Gold Nanorods for Biophotonics 10:30-11:00 1st Conference Room (3F)
Biography for Ken-Tye Yong
Ken-Tye Yong is an Associate Professor in School of Electrical and Electronic Engineering at the Nanyang Technological University. He received his PhD from Chemical and Biological Engineering in SUNY at Buffalo in 2006. Following completion of his graduate studies, he did his post-doc at the Institute for Lasers, Photonics and Biophotonics in SUNY at Buffalo from 2006 to 2009, where his research focus is in the area of biophotonics, nanophotonics, and nanomedicine. He has published over 150 scientific papers, 5 book chapters and he also holds a number of patents. He has served as an editor, associate editor, a guest editor, and an editorial board member for Theranostics, Science of Advanced Materials, Journal of Solid Tumors, Journal of Nanoengineering and Nanomanufacturing, Frontiers in Nanobiotechnology, and Optical Nanoscopy. His academic honors include Early Career Teaching Excellence Award, Tau Beta Pi Engineering Honor Society, UB Visionary Innovation Award, Best Poster Award Winner in National Cancer Institute Alliance for Nanotechnology in Cancer Investigators Meeting for 2007, and American Association for Cancer Research (AACR)-Pancreatic Cancer Action Network Research Fellowship Award for 2008. Currently, His research group interests include engineering functional nanoparticles for biophotonic and nanomedicine applications, fabrication of implantable MEMS device for drug delivery, developing SPR nanosensor for biosensing, and nanodevices for photonics applications.
146 Oral-28
Plasmonic Gold Nanorods for Biophotonics
Ken-Tye Yong U "(&('
Abstract: In this talk, we will discuss a broad spectrum of our research studies on gold nanorods that are playing a critical role in advancing various nanobiophotonic technologies since their first use in plasmonic imaging. In the last 10 years, gold nanorods have been applied in biomedical applications such as tumor imaging, cancer cells detection, gene delivery and brain diseases therapy. These plasmonic metal nanoparticles can be engineered as a set of solutions to overcome challenges in current nanobiophotonic research fields such as highly sensitive optical diagnostic tools, biosensors, photothermal therapy and effective gene therapy. Gold nanorods are metallic nanoparticles in the nanometer sizes and they possess many unique optical properties, which have many advantages over traditional organic dyes or quantum dots as optical marker for biological applications such as two-photon luminescence imaging, dark-field imaging, and near-infrared absorption imaging. For example, by manipulating the aspect ratio of the gold nanorods, the longitudinal surface plasmon resonance peak can be systematically tuned from 600 to 1500 nm. In addition, the plasmon absorption of gold nanorods can be tailored by changing their size, shape, and composition. This flexibility in optical tuning allows gold nanorods to have plasmon absorption from visible to near- infrared (NIR) region, a unique feature for harvesting specific needs in nanobiophotonic usages. In this talk, we will highlight the use of gold nanorods with different sizes, compositions, and shapes for nanobiophotonic applications (e.g. guided bioimaging, multimodal imaging, biosensing, photothermal therapy, gene delivery, two-photon luminescence imaging, etc). Also, we will discuss important rules to be considered when designing gold nanorods for in vitro and in vivo applications and the future trend of using such nanomaterials in the nanobiophotonic field. In addition, the toxicity assessment of gold nanorods in cell culture and animal models will be presented. This talk is intended to promote the awareness of past and present developments of gold nanorods in nanobiophotonic fields, the potential toxicity of gold nanorods, and the approaches to engineer biocompatible gold nanorods, whereby encouraging researchers to think about exciting and new promising nanobiophotonic applications with gold nanorods in the years to come.
References 1. N Panwar, C Yang, F Yin, HS Yoon, TS Chuan, KT Yong; Nanotechnology 26 (36), 365101, 2015 2. F Yin, C Yang, Q Wang, S Zeng, R Hu, G Lin, J Tian, S Hu, RF Lan, KT Yong; Theranostics 5 (8), 818, 2015 3. T Gong, D Goh, M Olivo, KT Yong; Beilstein journal of nanotechnology 5 (1), 546-553, 2014 4. J Zhu, H Huang, KT Yong; NIR news 24 (8), 4-5, 2013 5. J Zhu, T Gong, A Kopwitthaya, R Hu, WC Law, I Roy, H Huang, KT Yong; RSC Adv. 3 (30), 12280- 12286, 2013 6. T Gong, M Olivo, US Dinish, D Goh, KV Kong, KT Yong; Journal of biomedical nanotechnology 9 (6), 985-991, 2013 7. J Zhu, A Kopwitthaya, KT Yong, R Hu, WC Law, I Roy, H Huang; Nanoscience and Nanotechnology Letters, 5 (2), 195-197, 2013 8. JR Runyon, A Goering, KT Yong, SKR Williams; Analytical chemistry 85 (2), 940-948, 2012 9. D Goh, T Gong, US Dinish, KK Maiti, CY Fu, KT Yong, M Olivo; Plasmonics 7 (4), 595-601, 2012 10. SD Mahajan, R Aalinkeel, JL Reynolds, B Nair, DE Sykes, A Bonoiu, I Roy, KT Yong; Immunological investigations 41 (4), 337-355, 2012 11. R Masood, I Roy, S Zu, C Hochstim, KT Yong, WC Law, H Ding, UK Sinha; Integrative Biology 4 (2), 132-141, 2012 12. AC Bonoiu, EJ Bergey, H Ding, R Hu, R Kumar, KT Yong, PN Prasad; Nanomedicine 6 (4), 617-630, 2011 13. L Liu, H Ding, KT Yong, I Roy, WC Law, A Kopwitthaya, R Kumar; Plasmonics 6 (1), 105-112, 2011 14. A Kopwitthaya, KT Yong, R Hu, I Roy, H Ding, LA Vathy, EJ Bergey; Nanotechnology 21 (31), 315101, 2010 15. J Zhu, KT Yong, I Roy, R Hu, H Ding, L Zhao, MT Swihart, GS He, Y Cui; Nanotechnology 21 (28), 285106, 2010 16. AC Bonoiu, SD Mahajan, H Ding, I Roy, KT Yong, R Kumar, R Hu, PN Prasad; Proceedings of the National Academy of Sciences 106 (14), 5546-5550, 2009
147 Oral-26
A non-PCR Surface Plasmon Resonance Platform with Aptamer-based Bio-barcode assay for anti-cancer drug screening application
Jacky F.C. Loo1,2,a, S.Y. Wu1,b, H.C. Kwok1,c, H.P. Ho*1,d, S.K. Kong2,e U C F U C F U C F U C F
Abstract:ġ Liver cancer is a major health hazard and millions of new cases are appeared worldwide each year. It has a high fatality rate because multi-drug resistance (MDR) is frequently developed during cancer therapy especially chemotherapy. Therefore, searching for new drugs that overcome MDR has become an urgent need to treat the patient suffered from cancer with MDR. Cytochrome c (cyto-c) is known as a cell death biomarker as it is a tight regulator that triggers apoptosis in cancer cells after release from the mitochondria due to mitochondrial damage by anti-cancer drug. In this study, we develop an aptamer-based bio- barcode-RNase H-surface plasmon resonance (ABC-RNase-SPR) assay for cyto-c biosensing. We have previously developed an aptamer to detect cyto-c from cell and mitochondrial fraction. This aptamer, a short (76-mer) single-stranded DNA with unique 3D structure by DNA folding was selected with a high binding affinity and specificity to cyto-c from a synthetic DNA library. In our ABC assay, cyto-c is firstly captured by a micro-magnetic particle (MMP) coated with capturing antibodies (Abs). After that, aptamer, acting as both recognition element and signal reporter, binds on the cyto-c-Abs-MMP complex. While polymerase amplification such as PCR and fluorescent labeling is needed for conventional ABC assay to amplify the aptamer signal for detection, we simultaneously exploit RNase H for signal amplification and surface plasmon resonance for fluorescent label-free detection (SPR). RNase H is employed after the ABC assay to specifically hydrolyze the RNA probes immobilized on the gold surface when they hybridize with their target aptamer sequence. Enzyme digestion then releases an aptamer from the RNA-aptamer hybrid for binding with a new RNA probe which starts another reaction cycle for signal amplification. This whole assay can be completed within 3 hours without thermal cycling. Using this ABC-RNase-SPR assay, some potential anti-cancer drugs have been screened for their effectiveness to kill liver cancer cell in vitro especially with multi-drug resistance.
Fig 1. Schematic diagram of ABC-RNase-SPR assay.
References: [1] A. Osaka, H. Hasegawa, Y. Yamada, and K. Yanagihara, J. Cancer Res. Clin. Oncol. 135, 371M377 (2009). [2] F.C. Loo, S.P. Ng, C.M. Wu, and S.K. Kong. Sensor. Actuat. B-Chem. 198, 416-423 (2014). [3] H. Inoue, Y. Hayase, S. Iwai, and E. Ohtsuka, FEBS Letters. 11, 327-330 (1987).
148 Oral-29
" < ! @ < < ! \&$ ] Advanced Functional Thin Films Department, Surface Technology Division, Korea Institute of Materials Science (KIMS)
Periodic metallic nanostructures have been studied extensively due to their potential applications for nanophotonics and optofluidics. Interference lithography (IL) has great potential for simple and rapid production of defect-free ordered nanostructures over large areas up to cm2 with one laser exposure.[1][2] In IL, multi-beam optical interference produces multi-dimensional intensity profile of light in space. The interference-induced intensity profile can be transferred to photosensitive materials in very short exposure times. More importantly, IL allows for precise control of the feature size, pattern shift, and a variety of lattice symmetries through a proper arrangement of laser beams. Here, we report on the fabrication of the various metallic nanostructures for highly sensitive and uniform plasmonic sensing applications. Highly ordered polymer nanostructures are generated by single prism IL, and following metal coating and lift-off processes can lead to the generation of 2D and 3D nanostructured plasmonic materials.[3] Ridges on the structural surfaces along the z-direction were formed via the standing wave effects.[4] Finally, we also briefly mention Ag nanowire-based surface-enhanced Raman spectroscopy (SERS) substrates.[5]
[1] S.-K. Lee, S.-G. Park, J. H. Moon, S.-M. Yang, Lab Chip ^, 388M391 (2008). [2] S.-G. Park, S.-K. Lee, J. H. Moon, S.-M. Yang, Lab Chip 2009, , 3144M3150 (2009). [3] T. Y. Jeon, H. C. Jeon, S. Y. Lee, T. S. Shim, J. D. Kwon, S. G. Park, S. M. Yang, Adv. Mater. %=, 1422M 1426 (2014). [4] T. Y. Jeon, S.-G. Park, D.-H. Kim, S.-H. Kim, Adv. Funct. Mater. %`, 4681M4688 (2015). [5] S.-G. Park, C. Mun, M. Lee, T. Y. Jeon, H.-S. Shim, Y.-J. Lee, J.-D. Kwon, C. S. Kim, D.-H. Kim, Adv. Mater. %, 4290M4295 (2015).
149 Oral-32
Metasurface for creating orbital angular momenta and microparticle manipulations
Chen-Bin Huang U U C C U
Abstract: The generation of optical vortices using plasmonics has drawn immense recent research attentions. However, in the past, these near-field vortices carrying orbital angular momentum were excited by waves that carry spin angular momentum, i.e., circularly polarized waves. In this talk, I will introduce the advantage of a designed metasurface, in which vortices could be created under linearly polarized excitations. I will also illustrate the applications of such novel device for multiple selective controls to micro-particles.
1. Introduction to main text format and page layout Optical vortices are waves carrying orbital angular momentum and exhibit helical phase fronts. Helical phase front leads to discontinuous azimuthal phase jumps and the number of phase discontinuities (abrupt phase jumps fromto) within a 2 range is referred to as the topological charge of an optical vortex. Optical vortices have been applied in trapping and spinning of micro-particles, and recently in free-space data transmission. Generation of optical beams carrying orbital angular momentum has received increasing attentions recently, both in the far-field and in the near-field. Near-field vortices are typically generated through the excitation of surface plasmons (SPs) [1-3]. However in the past, SP vortices were generated using circularly polarized optical excitations that carry spin angular momentum (SAM). The functionality of the plasmonic spiral/slot can thus be understood as the conversion from far-field optical SAM to near-field orbital angular momentum (OAM) given by the chirality of the device. In the first part of this presentation, a nanocavity embedded in a gold thin film is carefully designed and arranged to form a metasurface. For the first time to our best knowledge, we demonstrated numerically and experimentally the ability to generate SP vortex carrying OAM in our designed metasurface under linearly polarized optical excitation that carries absolutely no angular momentum [4]. Figure 1(a) shows the schematics of our design. Our numerical studies are performed using three-dimensional finite-difference time- domain (FDTD) method simulations. A single nanocavity is formed by embedding a crossed air-slit onto a gold thin film of 200 nm thick over a silica substrate. The arm lengths of the air-slits are 500 nm in the x- and 780 nm in the y-directions, respectively. When a normally incident laser source illuminates the nanocavity, SPPs polarized in the z-direction with distinct spatial and phase characteristics can be selectively excited depending on the input laser polarization. In our current design, the difference in the arm lengths is optimized } 4² (-4² } } ¯ ¯ nm is 45° (-45°) linearly polarized, as shown in Fig. 1(b) (Fig. 1(c)), respectively. The resulting local SPP vortex fields are beneficial in the later generation of near-field optical OAM. The near-field experimental results will also be presented.
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! Figure 1. (a) Schematics of a single nanocavity. Instantaneous Ez field when the laser input is linearly (b) 45°- polarized, (c) -45°-polarized, respectively.
References [1] W.-Y. Tsai, J.-S. Huang, and C.-B. Huang, Nano Lett. 14, 547-552 (2014). [2] C.-F. Chen, C.-T. Ku, Y.-H. Tai, P.-K. Wei, H.-N. Lin, and C.-B. Huang, Nano Lett. 15, 2746-2750 (2015). [3] C.-T. Ku, H.-N. Lin, and C.-B. Huang, Appl. Phys. Lett. 106, 053112 (2015).
150 Session: THU-R2-S2
Date: March 24 (Thursday) Time: 10:30-12:00 Session Chair: Junichi Takahara (Osaka University, Japan) . . % ? 1 Room: 2nd Conference Room (3F) THU-R2-S2 Invited talk
Prof. Jian Wen Dong
Sun Yat-Sen University, China
Molding the spin flow in valley photonic March 24, 2016 10:30-11:00 crystals 2nd Conference Room (3F)
Biography for Jian Wen Dong
Jian-Wen DONG received Ph. D. in Sun Yat-sen University, China and promoted as Professor in the same affiliation. He was the visiting researcher in UC Berkeley and HKUST. Starting from 2003, Dr. Jian-Wen Dong has been working in the fields of molding the flow of light in artificial in-homogenous materials including photonic crystal, metamaterials, and plasmonic materials. Dr. Dong has published over 40 research papers in scientific journals including Nat. Commun., Phys. Rev. Lett., Adv. Mater., Sci. Rep., Opt. Exp., etc. Recently, Dr. Dong has some academic contributions on photonic spin-momentum locking in bulk valley photonic crystals and at the boundary of topological photonic crystals; zero-refractive-index quasicrystals; polygon-based computer generated hologram. Dr. Dong got the NSFC “Grant for excellent young scientist” in 2015.
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153 Oral-27
Plasmonic core-satellite assemblies with high yield and stability
Tien-Hsin Lin, Li-Ching Huang, Zhi-Yen Liu, Jyun-Hao Chen, Yi-Chen Wang, Shiuan-Yeh Chen* F U U & &
Abstract: Plasmonic structures are attractive due to their promising and diverse optical properties. New optical properties can be generated and engineered through the coupling of two or several types of individual elements. For 3D plasmonic structures, molecule-linked coupled structures usually suffer from low efficiency, long reaction time, complicated synthesis processes and low stability. In this report, core-satellite assemblies are formed simply through one-step polyelectrolyte coating in a short time with high output efficiency. The whole structure is robust under the laser illumination and additional silica coating process, which is confirmed by Raman spectra. These assemblies can be used as Raman tags for Raman imaging.
Introduction Plasmonic structures are attractive due to their optical properties in the near-field and far-field. In the near-field, the enhanced field they generated strongly interacts with materials in proximity to the surface and even produces the quantum hybrid states in the strong coupling regime. In the far-field, the larger scattering cross section of plasmonic particles provides better contrast for tissue imaging. In addition, the strong absorption can generate substantial amount of heat for cancer cell elimination. These optical properties are usually engineered through tuning the size and morphology of individual nanoparticles by various chemical synthesis methods. The alternative way is to use coupled structure based on existing particles. The molecule- linked structure is a common way for 3D plasmonic materials. However, to produce coupled structures in the solution phase is not an easy task. The formation of linkage between linker molecules is usually at low efficiency and time-consuming. Increasing the concentration of linker molecules may increase the reaction speed but also result in the random aggregation of particles. In this work, a polyelectrolyte coating is used to connect spherical nanoparticles of different sizes to form core-satellite assemblies (CSA). The coupled core-satellite structure is formed almost immediately after the solutions of two particles are mixed. The output efficiency is nearly 100%. The CSA is robust under the additional silica shell coating and strong laser illumination.
Fig. 1. The TEM images of a single core nanoparticle, CSA and silica-coated CSA and their corresponding absorption spectra. Results As shown in Figure 1, for each core particles, the average number of the attached satellite particle is around 8. The excess particles are thoroughly removed from the solution during the final centrifuge process. For the silica- coated CSA, the thickness of silica shell is around 10 nm. The extinction spectrum is used to probe the plasmonic resonance wavelength of these structures. The resonance of single 50 nm nanoparticle is at 530 nm whereas for CSA structure, there are two valley points. The first valley point is from the single particle resonance which is also at 530 nm and the other is from the particle-particle coupling. This resonance is at 610 nm. The main absorption shifted from 530 nm to 610 nm is the reason that the color changes from red to blue during the synthesis process. Due to the silica coating and slight aggregation, the resonance CSA is shifted to 640 nm. The stability of this CSA is confirmed by the Raman spectra and this assembly can be used as Raman tags.
[1] C-Z. Huang, M.-J. Wu, S.-Y. Chen, J. Phys. Chem. C. 107, 23-30 (2015). [2] J. J. Mock, S. M. Norton, S.-Y. Chen, A. A. Lazarides, D. R. Smith, Plasmonics, 6, 1, 113-124 (2011) [3] S.-Y. Chen, J. J. Mock, R. T. Hill, A. Chikoti, D. R. Smith, A. A. Lazarides, ACS nano, 4, 11, 6535-6546 (2010)
154 Oral-30
Experimental Determination of Absorption, Scattering, and Photoacoustic Signal from Gold Nanoparticles
Genny A. Pang1,*, Adomas Griauslys1, Max Aumiller2, Adrian Rühm2, Christoph Haisch1 1Chair for Analytical Chemistry & Institute of Hydrochemistry, Technische Universität München, Marchioninistraße 17, 81377 Munich, Germany, 2Laser-Forschungslabor, LIFE-Centre, Ludwig-Maximilians-University Munich, Marchioninistraße 23, 81377, Munich, Germany E-mail address: *[email protected]
Abstract: We experimentally investigate the relationship between absorption, scattering, and photoacoustic signal of different gold nanoparticle suspensions. The absorption and scattering coefficients of the suspension were determined using an integrating sphere setup, and the photoacoustic signals were measured in a custom-built cuvette. Our preliminary results show that the scattering coefficient increases with particle size, and also with additional chemical treatment of the gold nanoparticle, such as with coatings. Our results suggest that the absorption coefficient, instead of the optical density, is important to quantitatively analyze the signal generation efficiency from photoacoustic excitation of nanoparticle suspensions.
1. Introduction and Theory State-of-the-art research in photoacoustic imaging for biomedical imaging includes advances in the use of exogenous contrast agents such as gold nanoparticles. Although studies have been quick to qualitatively show the enhanced contrast offered when gold nanoparticles are employed in photoacoustic imaging, much is still left unknown about the fundamental signal generation process during photoacoustic excitation of nanoparticles. Our work aims to improve the basic knowledge of photoacoustic signal generation from nanoparticle suspensions, including the relationship between absorption, scattering, and photoacoustic signal generation efficiency. During biomedical photoacoustic imaging, absorption of optical energy by tissue chromophores causes heating and thermal expansion of the tissue, resulting in the generation of acoustic waves. In the case of photoacoustic signal generation from optical absorption by nanoparticles, the local heating and thermal expansion occur mostly in the surrounding medium, and not in the particle itself [1-3]. As a result, the rate of energy transfer from particle to fluid is suggested to have an influence on the photoacoustic signal [1]. The size of the absorbing particle, therefore, may influence the energy transfer rate and the photoacoustic signal generation efficiency. While studies have qualitatively found a dependence on particle size and the presence of a chemical coating [1,4], there still exist discrepancies in the literature on the quantitative nature of this effect.
2. Methods, Results and Conclusions In our work-in-progress study we use an integrated sphere system to directly measure the optical properties, including the absorption and scattering coefficients, of liquid suspensions of nanoparticles of different diameters with and without coatings for influencing the heat transfer efficiency. These nanoparticle suspensions were further investigated in a custom-built photoacoustic cuvette. Our combined measurements of photoacoustic signal and absorption coefficient enable us to directly analyze the relationship between the photoacoustic signal and the absorbed optical energy without having to make assumptions about the scattering contribution. The preliminary results show that the scattering coefficient increases with particle size, and the scattering contribution to the optical density can differ from the predictions by simple Mie theory calculations [5], especially if the particles are additionally treated, such as with a coating to improve the heat transfer efficiency to the suspension. Therefore, using optical density, as typically done in the literature [1-2], to quantitatively compare photoacoustic signals from nanoparticle suspensions can lead to misinterpretation of the quantitative photoacoustic signal generation efficiency. The results of our preliminary study show that our combined experimental methods can be applied to validate models describing the relationship between absorbed optical energy and conversion to measureable acoustic energy. This type of data is essential to improving knowledge about the fundamental photoacoustic signal generation from nanoparticles, including the heat energy transfer process from the particle to the suspension fluid, and as a result, can enable future quantitative photoacoustic imaging for nanoparticles used as contrast agents, increasing the capabilities of photoacoustic imaging in biomedicine.
3. References [1] Y. S. Chen, W. Frey, S. Aglyamov and S. Emelianov, Small, 8(1), 47-52 (2012). [2] O. Simandoux, A. Prost, J. Gâteau, and E. Bossy, Photoacoustics, 3(1), 20-25 (2015). [3] H. Shinto, T. Fukasawa, H. Aoki, S. Ito, and M. Ohshima, Colloids and Surfaces A, 430, 51-57 (2013). [4] T. Fukasawa, H. Shinto., H. Aoki, S. Ito, and M. Ohshima, Advanced Powder Technology, 25(2): 733- 738 (2014). [5] P. K. Jain, K. S. Lee, I. H. El-Sayed, and M. A. El-Sayed, The Journal of Physical Chemistry B, 110(14), 7238-7248 (2006).
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Bio-metamaterial: Black Ultrathin Gold Film Fabricated on Lotus Leaf
Yuusuke Ebihara,1 Ryoichi Ota,2 Takahiro Noriki,2 Masayuki Shimojo2 and Kotaro Kajikawa1 1 B U U '$ E 2 U F U "$ '$ ' E
Abstract: A black metamaterial is reported fabricated on a lotus leaf used as a template. In spite of the extremely thin gold coating (10-nm thick) on the lotus leaf, the surface shows reflectivity below 0.01 over the entire visible spectral range. Finite-difference time-domain (FDTD) calculations suggest that the low reflectivity stems from the secondary structures on the lotus leaf, where randomly oriented nanorods are distributed.
1. Introduction It is well-known that the surface of lotus leaf is highly water-repellent. This great repellency stems from microscopic bumps having secondary roughness [1], which produces the large surface tension resulting in great resistance of water. Our scanning electron microscope (SEM) image of a lotus leaf revealed that the secondary roughness is composed of assemblies of nanorods. Therefore, we consider that lotus leaves are promising templates for metamaterials. Here we report blackbody metamaterials formed on a leaf of lotus ( ). The rough bumps play as a good template for the blackbody bio-metamaterials [2].
2. Results and discussions The lotus leaf (cotyledon) is covered with gold by sputtering in air. The thickness of the gold is 10 nm. The surface looks dark black as shown in Fig. 1(a). Figure 1(b) shows fine SEM image of the leaves covered gold. The surface is composed of many macaroni-like nanorods in the sample of sputtered gold. The reflectance from the surface of 10-nm thick sputtered gold is less than 1.0% over the visible spectrum range. Finite-difference time-domain (FDTD) calculations suggest that the low reflectivity stems from the secondary structures on the lotus leaf, where randomly oriented nanorods of gold are distributed on the substrate.
3. Conclusion We fabricated blackbody metamaterials using a lotus leaf used as a bio-template. The reflectance is less than 1.0 % over the visible spectrum range. This property originates from the fine structure of lotus leaves. We have shown that nanostructures in nature is good template for metamaterials.
Figure 1 (a) photographic image of metamaterials. (b) SEM image of metamaterials.
[1] C. W. Extrand, Langmuir 27 6920-6925 (2011). [2] Y. Ebihara, R. Ota, T. Noriki, M. Shimojo and K. Kajikawa Sci. Reports, 5, 15992 (2015).
156 FRI-IC-S1
Session: FRI-IC-S1
Date: March 25 (Friday) Time: 08:30-10:10 Session Chair: = ` = 0 7 . . R . % ? 1 Room: Invited talk
Prof. Qihuang Gong
Peking University, China
Manipulating Light with Nano Photonic March 25, 2016 08:30-09:00 Structures International Conference Hall (4F)
Biography for Qihuang Gong
Qihuang Gong is the Cheung Kong Professor of Physics at Peking University, China, where he is also the Founding Director of the Institute of Modern Optics. He also serves as the Vice Provost and Executive Vice Dean of Graduate School of Peking University. In addition, Prof. Gong serves as Director of the State Key Laboratory for Mesoscopic Physics. His current research interests are in ultrafast optics, nonlinear optics, and mesoscopic optical devices for applications. He has received the State Natural Science Award (2nd-Class), the Chinese Physical Society’s Rao Yutai Prize, and the Wang Daheng Science and Technology Prize given by the Chinese Optics Society. He is the Member of Chinese Academy of Sciences, Fellow of OSA and Fellow of IoP. He serves as the General Secretary and Vice President of the Chinese Optical Society, Vice President of the Chinese Physical Society.
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+ ] $ $ ' $ ! F '&
Nano photonic structures permit remarkable control of the propagation of light. A selection of recent results will be presented. Using two-dimensional photonic crystal made of the composite materials with large and fast third-order optical nonlinearity, ultrafast and low threshold all-optical switching was demonstrated. Based on tunable Fano resonance or PIT of metallic nano-structures, ultrafast modulations on light transmission were also demonstrated. Moreover, ultracompact plasmonic devices including SPP unidirectional generator, splitter and others were experimentally demonstrated.
[1] Chen, JJ; Li, Z; Yue, S; Gong, QH, Highly Efficient All-Optical Control of Surface-Plasmon-Polariton Generation Based on a Compact Asymmetric Single Slit, NANO LETTERS, 11(7) (2011) 2933-2937 [2] Hu, XY; Zhang, YB; Fu, YL; Yang, H; Gong, QH, Low-Power and Ultrafast All-Optical Tunable Nanometer-Scale Photonic Metamaterials, ADVANCED MATERIALS, 23(37) (2011) 4295-4300 [3] Chen, JJ; Li, Z; Yue, S; Xiao, JH; Gong, QH*, Plasmon-Induced Transparency in Asymmetric T-Shape Single Slit, NANO LETTERS, 12(5) (2012) 2494-2498 [4] Zhu, Y; Hu, XY; Fu, YL; Yang, H; Gong, QH, Ultralow-power and ultrafast all-optical tunable plasmon- induced transparency in metamaterials at optical communication range, SCIENTIFIC REPORTS, 3 (2013) 2338. [5] Zhu, Y; Hu, XY; Yang, H; Gong, QH, On-chip plasmon-induced transparency based on plasmonic coupled nanocavities, SCIENTIFIC REPORTS, 4 (2014) 3752. [6] Chen, JJ; Sun, CW; Li, HY; Gong, QH, Ultra-broadband unidirectional launching of surface plasmon polaritons by a double-slit structure beyond the diffraction limit, NANOSCALE, 6(22) (2014) 13487- 13493. [7] Lu, CC; Hu, XY; Zhang, F; Yang, H; Gong, QH, Multilayer Graphene: Polycrystalline ITO for Ultralow- Power Active Control of Polarization-Insensitive, Metamaterial-Induced Transparency, ADVANCED OPTICAL MATERIALS, 2 (12) (2014) 1141-1148. [8] Yao, WJ; Liu, S; Liao, HM; Li, Z; Sun, CW; Chen, JJ; Gong, QH, Efficient Directional Excitation of Surface Plasmons by a Single-Element Nanoantenna, NANO LETTERS, 15(5) (2015) 3115-3121. [9] Chen, JJ; Sun, CW; Rong, KX; Li, HY; Gong, QH, Polarization-free directional coupling of surface plasmon polaritons, LASER & PHOTONICS REVIEWS, 9(4) (2015) 419-426..
159 Invited talk
Prof. Zouheir Sekkat
Moroccan Foundation for Science Innovation and Research, Morocco
Towards Ultra-high Sensitivities in Plasmon March 25, 2016 09:00-09:30 Based Optical Sensors International Conference Hall (4F)
Biography for Zouheir Sekkat
Zouheir Sekkat is a Professor at the University Mohammed V, Rabat, Morocco, and the founder and the director of the Optics and Photonics Center at the Moroccan Foundation for Science Innovation and Research, and a cross appointed professor of Osaka University. He was a visiting scientist of RIKEN, Wako, Japan. He was Associate Professor of Osaka University as a regular faculty member of the Department of Applied Physics. He completed his Master and PhD and Habilitation degrees, all from Paris-Sud University, Orsay. Sekkat did post-doctoral research stays at the following institutions: Max-Planck Institute for Polymer Research, Germany, and at CPIMA jointly between the University of California-Davis and IBM-Almaden at San Jose, and Stanford University. Professor Sekkat contributed to the optics and photonics community, at a pioneering level, in interfacing photochemistry and nonlinear optics (NLO) and polymer science. His actual Research Interests, include, photomigration, and thin film photovoltaics, and plasmonics and interaction of waveguides and plasmons. He is recipient of several prizes and honours, and he was appointed by his Majesty the King of Morocco, Mohamed VI, as a member of the Hassan II Academy of Sciences and Technology.
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] @ \\ Optics and Photonics Center, Moroccan Foundation for Advanced Science, Innovation and Research (MAScIR) Faculty of Sciences, Mohammed V University, Rabat, Morocco Graduate School of Engineering, Osaka University, Suita, Japan E-mail address: [email protected]
During the past few years, we have been involved in the study of optical sensors, in particular the plasmonic sensors, to achieve ultra-high sensitivities. As is well known, the sensitivity of the conventional surface plasmon resonance (SPR) sensor based on a single layer of Au is not very high because of the broad lineshape of the resonance. Several attempts have been made so far to improve the sensitivity by using long- range surface plasmons and waveguide (WG) modes. We propose here alternative ways to improve the sensitivity and to achieve extremely high sensitivities. Based on our appropriate formulation of the figure of merit of sensor sensitivity, we performed extensive numerical calculations for KretschmannRs configurations constructed by Au, Ag, Cu and Al films [1]. The figures of merit obtained for a wide range of the wavelength from the ultraviolet to the infrared regions allow us to optimize the structure to achieve the best performance for bulk and thin film sensing.. We also studied both theoretically and experimentally multilayer structures that give sharper resonances and higher sensitivities. One of the promising structure is metal-insulator-metal structures that support symmetric and antisymmetric surface plasmon polaritons (SPPs) arising from the coupling between two SPPs at the metal-insulator interfaces. Experiments performed on Ag-PMMA-Ag structures demonstrated a reflectance dip much sharper than that exhibited by a single layer of Ag, in good agreement with results of theoretical calculations [2]. The appearance of the sharp dip can be explained by the anticrossing behavior of the SPP dispersion curves. Recently, we have found that an alternative multilayer structure shown in Fig. 1 gives extremely narrow resonances and high sensitivities [3,4]. The structure can be regarded as a combination of a SPP structure presented in Fig. 1(a) and a WG structure shown in Fig. 1(b). In the structure shown in Fig. 1 (c), SPP and WG modes can interact with each other through the overlap of their evanescent fields inside the spacer layer (Dielectric 1). The coupling of the modes generates very sharp resonances as shown in Figs. 2(a) and 2(b). The lineshape seen in Fig. 2(a) is so-called plasmon-induced transparency and that seen in Fig. 2(b) is Fano lineshape. It should be stressed that these lineshape, in particular the Fano lineshape, are very much sharper than the conventional SPR and exhibit shifts when the refractive index of the surrounding medium (water) is changed. According to our estimations, the figure of merit of sensitivity by intensity of this type of sensor can be 107 times as large as that of the conventional SPR and WG sensors, provided that the loss in the dielectric layers is sufficiently small. The proposed structure is very much suited for applications, because it does not require any nanofabrication procedure. Experimental confirmation of the ultra-high sensitivities is now underway in our laboratory.
[1] D. V. Nesterenko and Z. Sekkat, Plasmonics, ^, 1585 (2013). [2] S. Refki, S. Hayashi, A. Rahmouni, D. V. Nesterenko and Z. Sekkat, Plasmonics ^, (2015), DOI 10.1007/s11468-015-0047-7. [3] S. Hayashi, D. V. Nesterenko and Z. Sekkat, APEX, ^, 022201 (2015) [4] S. Hayashi, D. V. Nesterenko and Z. Sekkat, J. Phys. D:Appl. Phys., [^, 325303 (2015).
Fig.1 WG-coupled surface plasmon sensor Fig. 2 PIT and Fano lineshapes
161 Oral-34
Enhancing Surface Sensitivity of Metallic Nanostructures Using Oblique-Angle Induced Fano Resonances
Kuang-Li Lee, Chia-Chun Chang, Ming-Yang Pan and Pei-Kuen Wei Research Center for Applied Sciences, Academia Sinica, Taipei, 11529, Taiwan. [email protected]
Abstract: The surface sensitivity is an important factor that determines the minimum amount of biomolecules detected by surface plasmon resonance sensors. We proposed using small angle incidence to increase the surface sensitivity of periodic metal nanostructures. For capped silver nanoslit arrays with normal light incidence, there are two distinct resonance bands. One has a sharp resonance peak (3.9 nm bandwidth) resulted from Bloch wave surface plasmon polariton (BW-SPP) on the surface. The other is a broadband resonance (~ 50 nm bandwidth) produced by gap plasmon in the slit. Under oblique incidence, the coupling of gap plasmon to the split BW-SPP generates an asymmetric Fano resonance. Compared to normal incidence, the surface sensitivity of the coupled mode is improved by 2.5 times. The calculations show the evanescent tail of surface plasmon wave was reduced from 300 nm to 100 nm when Fano coupling occurs. It verifies the improved surface sensitivity is attributed to the decrease of evanescent tail.
1. Introduction to main text format and page layout Periodic metal nanostructures offer a simpler way for SPR excitation. Metallic nanohole arrays, nanoslit arrays and capped nanoslit arrays have been utilized for biosensing applications. To evaluate the quality of the sensor, a figure of merit (FOM) value is utilized. The FOM in wavelength units is defined as m (nm/RIU)/fwhm (eV), where m is the linear regression slope for the refractive index dependence (bulk sensitivity) and fwhm is the resonance width of the plasmon resonance. The sensing ability can be improved by increasing the bulk sensitivity or narrowing the bandwidth. To reduce the bandwidth, a thermal-annealing template-stripped method is utilized to make high-quality metallic nanostructures.[1] Another approach to achieve sharp spectral response is based on Fano resonances.[2] The Fano resonance exhibits a distinctly asymmetric shape which arises from the spectral overlapping between a broad resonance and a narrow discrete resonance. In this study, we proposed oblique-angle induced Fano resonances to increase the surface sensitivities of capped silver nanoslit biosensors. Under oblique angle incidence, the resonance peak was split into two resonance peaks. The coupling of the broadband gap plasmon resonance to one of the split Bloch wave surface plasmon polariton mode generates an asymmetric Fano resonance. We further studied the surface sensitivity of capped silver nanoslits under different incident angles from 0° to 55° by measuring the interactions between bovine serum albumin (BSA) and anti-BSA. The result shows that the wavelength shift of the coupled resonance mode was improved by 2.5 times. We attribute the improved surface sensitivity to the decrease of the decay length.
Fig. 1 (a) A schematic configuration depicts the geometrical parameters of the capped sliver nanoslits. (b) A schematic illustration demonstrates the Fano resonance in capped nanoslits under oblique angle incidence. (c) The measured transmission spectra in air with different incident angles from 0° to 15°. The inset shows the bandwidth was 3.9 nm for normally-incident TM-polarized light. (d) Experimental peak wavelengths of the coupled modes and theoretical resonant wavelengths of BW-SPPs as a function of the incident angle. References [1] K. L. Lee, P. W Chen, S. H. Wu, J. B. Huang, S. Y. Yang, P. K. Wei, ACS Nano , 2012, 6 (4), pp 2931M 293 [2] K. L. Lee, J. B. Huang, J. W. Chang, S. H. Wu, P. K. Wei, "Ultrasensitive Biosensors Using Enhanced Fano Resonances in Capped Gold Nanoslit Arrays", Sci. Rep. 2015, 5, 8547..
162 Oral-37
Comprehensive Three-Dimensional Analysis of Surface Plasmon Polariton Modes at Uniaxial Liquid Crystal- Metal Interface
Yu-Ju Hung*, Yin-Ray Yen, Tsun-Hsiun Lee, Zheng-Yu Wu, Tsung-Hsien Lin F U ' S
Abstract: This paper describes the derivation of surface plasmon polariton modes associated with the generalized three-dimensional rotation of liquid crystal molecules on a metal film. The calculated dispersion relation was verified by coupling laser light into surface plasmon polariton waves in a one-dimensional grating device. The grating-assisted plasmon coupling condition was consistent with the formulated kspp value. This provides a general rule for the design of liquid-crystal tunable plasmonic devices.
1. Introduction The analysis of surface plasmon waves at the interface between an anisotropic dielectric layer and a noble metal is an intriguing and complex phenomenon in the field of metamaterial research. From a practical perspective, an anisotropic layer can be fabricated using e-beam lithography, bulk crystal growth, or through the application of spin-coated materials, such as liquid crystals (LC) or anisotropic organic layers. LC materials are an obvious choice with regard to the optical and electrical tailoring of the anisotropic properties. A lack of analysis on the 3D rotation of LC molecules on the thin metal film (two interfaces) restricts our understanding of this category phenomenon. Comprehensive wave analysis associated with the 3D rotation of LC optical axis (OA) has yet to be achieved. In this paper, we extend the scope of [15, 25] by performing 3D analysis for the LC on a thin metal film deposited on a glass substrate, specifically for E7 material, which has no=1.52 and ne=1.75 at 532nm. In the three layer system in Fig. 2, z>d/2 is the LC layer, d/2>z>-d/2 is the metal layer, and z<-d/2 is the isotropic layer.
Fig. 1. Structure of LC-metal-isotropic medium
A series field boundary conditions are defined and will be presented in the talk. The resulted boundary condition could be solved numerically and one simulation case is given: 532 , 40 , = 4.37 *1.63, noe 1.52, n 1.75 , the resulted dispersion curves are shown below. The two-interface problem introduces symmetrical as well as antisymmetrical modes. A series experimental data will be presented to verify the computational results.
Fig. 2. Eigen values resolved by using field boundary conditions 2. References [1] R. Luo, Y. Gu, X. K. Li, L. J. Wang, I. C. Khoo, and Q. H. Gong, App. Phys. Lett. 102(1), 011117 (2013). [2] X. L. Wang, P. Wang, J. X. Chen, Y. H. Lu, H. Ming, and Q. W. Zhan, App. Phys. Lett. 98(2), 021113 (2011).
163
FRI-R1-S1
Session: FRI-R1-S1
Date: March 25 (Friday) Time: 08:30-10:10 Session Chair: Hui Liu (Nanjing University, China) . .. . ` . 0 7 Taiwan) Room: 1st Conference Room (3F) Invited talk
Prof. Wolfgang Fritzsche
Leibniz Institute of Photonic Technology (IPHT), Germany
Bioanalytics using single plasmonic March 25, 2016 08:30-09:00 nanostructures 1st Conference Room (3F)
Biography for Wolfgang Fritzsche
Dr. Wolfgang Fritzsche heads the Nanobiophotonics Department at the Leibniz Institute of Photonic Technology (IPHT) in Jena, Germany. His research is focused on the interactions of localized surface plasmon effects in metal nanostructures with molecular components, and the implications for novel developments in biosensing as well as in nanooptics. The studies are conducted at the single particle level using the whole range of comparative ultramicroscopic characterization techniques. Examples for activities on the technical side are developments for a parallelization of the LSPR readout in a array format using imaging spectroscopy approaches, as well as electrical generation of plasmons overcoming the need for separate light sources. On the application side, the group is involved in DNA-based detection developments, e.g. for water pathogens, antibiotic resistance genes or sepsis-related fungi infection. Beside the sensing application, the effects observed in the immediate surrounding when plasmonic particles are irradiated with fs-laser pulses present another topic. Rhe observed excitation transfer along adjacent DNA nanowire represents a fascinating object for ongoing basic research studies.
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Bioanalytics using single plasmonic nanostructures
Thomas Schneider, Jacqueline Jatschka, Norbert Jahr, David Zopf, Andre Dathe, Janina Wirth, Pavlo Kliuiev, Frank Garwe, Andrea Csaki, Ondrej Stranik, Wolfgang Fritzsche Leibniz Institute of Photonic Technology (IPHT), A.-Einstein-Str. 9, Jena, Germany E-mail address: [email protected]
Abstract: Novel requirements for bioanalytical methods emerge due to trends such as personalized medicine or pathogen detection in environment and food. Here, innovative tools for diagnostics are needed, to be used outside of dedicated laboratories and with less qualified personnel, and with minimal costs. Plasmonic nanostructures promise to provide sensing capabilities with the potential for ultrasensitive and robust assays in a high parallelization, and without the need for marker. Upon binding of molecules, the localized surface plasmon resonance (LSPR) of these structure is changed, and can be used as sensoric readout. Here the use of individual nanostructures (such as gold nanoparticles) for the detection and manipulation of biomolecules (e.g. DNA) based on optical approaches is presented [1]. Holes in a Cr layer present an interesting approach for bioanalytics. They are used to detect even single plasmonic nanoparticles as labels or to sense the binding of DNA on these particles. This hybrid system of hole and particle allows for simple (just using RGB-signals of a CCD [2]) but a highly sensitive (one nanoparticle sensitivity) detection. Moreover, the binding of a molecular layer around the particles can be detected using spectroscopic features of just an individual particle [3]. The change in LSPR of individual metal nanoparticles is utilized to monitor the binding of DNA directly or via DNA-DNA interaction. The influence of different size (length) as well as position (distance to the particle surface) is thereby studied [4] using a dark-field approach developed a century ago [5]. The established serial approach is now further developed into a parallel readout using imaging spectrometric sensing based on interferometry and Fourier transformation. Besides sensing, individual plasmonic nanostructures can be also used to optically manipulate biomolecular structures such as DNA. Attached particles can be used for local destruction [6] or cutting as well as coupling of energy into (and guiding along) the molecular structure upon laser irradiation [7]. The resonance wavelength of these particles can not only manipulated by their inherent properties (material, geometry) or their surrounding, but also by coupling with adjacent metal films due to interferometric effects [8] or gap modes.
[1] A. Csaki, T. Schneider, J. Wirth, N. Jahr, A. Steinbrück, O. Stranik, F. Garwe, R. Müller and W. Fritzsche, Philosophical Transactions A 369, 3483-3496 (2011). [2] N. Jahr, N. Hädrich, M. Anwar, A. Csaki, O. Stranik and W. Fritzsche, Int J Env Anal Chem 93, 140-151 (2013). [3] N. Jahr, M. Anwar, O. Stranik, N. Hädrich, N. Vogler, A. Csaki, J. Popp, W. Fritzsche. J Phys Chem C 117, 7751-7756 (2013) [4] T. Schneider, N. Jahr, A. Csaki, O. Stranik and W. Fritzsche, J Nanopart Res 15, 1531 (2013) [5] T. Mappes, N. Jahr, A. Csaki, N. Vogler, J. Popp, W. Fritzsche. Angew Chem Int Ed 51, 11208-11212 (2012) [6] A. Csaki, F. Garwe, A. Steinbrück, G. Maubach, G. Festag, A. Weise, I. Riemann, K. König and W. Fritzsche, Nano Letters 7 (2), 247-253 (2007). [7] J. Wirth, F. Garwe, G. Haehnel, A. Csaki, N. Jahr, O. Stranik, W. Paa and W. Fritzsche, Nano Letters 11 (4), 1505-1511 (2011).; J. Toppari, J. Wirth, F. Garwe, O. Stranik, A. Csaki, J. Bergmann, W. Paa, W. Fritzsche, ACS Nano 7, 1291-1298 (2013); J. Wirth, F. Garwe, J. Bergmann, W. Paa, A. Csaki, O. Stranik, W. Fritzsche. Nano Letters 14, 570-577 (2014) [8] J. Wirth, F. Garwe, R. Mayer, A. Csaki, O. Stranik, W. Fritzsche: Nano Letters 14, 3809-3816 (2014)
167 Invited talk
Prof. Liwei Liu
Changchun University of Science and Technology, China
Heavy-metal free QDs preparation and March 25, 2016 09:00-09:30 biomedical application 1st Conference Room (3F)
Biography for Liwei Liu
Liwei Liu received BSc ,MSc and Ph.D.degrees from Changchun University of Science and Technology, She have made research in SUNY at Buffalo as a visiting scholar from March 2010 to March 2011, Prof. Liu has authored and co-authored more than 50 articles. Her research interests cover mainly optics, nanophotonic and biophotonic,and biological sensors.
168 IN-34
Heavy-metal free QDs preparation and biomedical application
Liwei Liu 4 4 + 4 + V + 6 Abstract:ġ In this paper, we report a heavy-metal free QDs, Cu2S, firstly, the surface of Cu2S QD will be modified to make it biocompatible and capable of controlled drug release. In addition, Cu2S is a highly NIR absorption material and it possesses strong nonlinear absorption. So secondly, Using this unique physical and optical property, drug release can be controlled by a femtosecond laser which can penetrate deeper to the tissue. This research is great significance to make the nanomaterials used in the clinical application.
1. Introduction to main text format and page layout Quantum dots (QDs) are fluorescent semiconductor nanocrystals with diameters in the range of 3M 7nm[1,2], or roughly 200M10000 atoms.1M5 Compared with organic mo- lecular chromophores, QDs possess many excellent proper- ties, including a tunable absorption spectrum, large extinction coefficients in a large wavelength range, long ex- citation lifetimes, and the capacity for multiple electron transfers. heavy-metal free QDs (Cu2S) is a very promising high-efficiency absorber with low toxicity[3]. In this work, we report the dBSA-Cu2S-based nanocarriers that are capable of an anticancer drug doxorubicin (DOX) to MCF-7 breast cancer cells. The developed nanotherapy formulation here, that combines chemotherapy and NIR window light-mediated therapy, will be seen to be taken in the clinical research for improving the therapeutic outcomes of the breast cancer.
Figure1. Figure 2.
(Figure 1. Photos of Dox +dBSA-Cu2S in different density. Figure2.FTIR spetrum of Dox-dBSA-Cu2S )
References [1] Prasad, P. N. Nanophotonics (Wiley-Interscience, New York, 2004). [2] Bailey, R. E.; Smith, A. M.; Nie, S. Quantum dots in biology and medicine. Phys. E. 25 (1) (2004). [3] F. Li, J. Wu, Q. Qin, Z. Li, and X. Huang, Powder Technol. 198, 267(2010). [4] Liu L, Wang Y, Hu S, et al. Second harmonic generation from direct band gap quantum dots pumped by femtosecond laser pulses[J]. Journal of Applied Physics, 2014, 115(7): 074303. [5] Yue Wang, Liwei Liu, Siyi Hu et.al, Simulation study based on the COMSOL Mutiphysics to the surface plasmon resonance of Cu2S quantum dots, Acta Physica Sinica, 2013, 62(19): 197803-197803.
169 Oral-35
Tunable tapered waveguide for efficient compression of light to graphene plasmons
Bo Han Cheng,1 Hong Wen Chen,2 Yung-Chiang Lan,2,* and Din Ping Tsai1 1Research Center for Applied Sciences, Academia Sinica, Taipei 115, Taiwan 2Department of Photonics and Advanced Optoelectronic Technology Center, National Cheng Kung University, Tainan 701, Taiwan *E-mail address: [email protected]
Abstract: In this paper, a dielectric-semiconductor-dielectric (DSD) tapered waveguide with magnetic tunability for efficient excitation of surface waves on DGD at terahertz region is proposed and analyzed. Efficient excitation of surface waves on DGD with various chemical potentials in graphene layer and incident frequencies can be attained by merely changing the external magnetic field applied onto the DSD tapered waveguide.
1. Introduction Surface plasmon polaritons (SPPs) propagating on a continuous noble metal film at visible region can support surface wave with size of hundreds of nanometers [1], while the extension length of electromagnetic field from the interface tends to be half of the wavelength of excited wave, limiting the pursuit of future device with ultrahigh density design. The wavelength and extension length of surface waves can be reduced to dozens of nanometer under terahertz illumination by replacing metal with two-dimensional material, graphene [2]. End-fire excitation method [3] is widely adopted for efficient excitation of surface wave at a dielectric- metal interface. However, the end-fire excitation is not efficient for directly exciting graphene’s surface wave due to large wavevector mismatch between terahertz light in free space and surface wave on graphene. In this work, we theoretically and numerically achieve a significant improvement in the controlling of energy transformation between incident light and surface wave on graphene at terahertz region for the demand of real application. 2. Simulation model and method Figure 1(a) and 1(b) plot the proposed indium antimonide (InSb)-based tapered waveguide and its side- view (in xy-plane), respectively. The tapered waveguide that consists of five dielectric-semiconductor- dielectric (DSD) elements (the semiconductor material is InSb) is placed in front of dielectric-graphene- dielectric (DGD) structure. All the simulated results are obtained by using COMSOL Multiphysics based on the finite element method (FEM). The semiconductor material in DSD is InSb. The relative permittivity of the substrate (i.e. the lower dielectric of DSD and DGD), 2 , is set to 3.0. The external magnetic field is applied along the z-direction (i.e. the Voigt configuration).
Fig. 1 Three-dimensional (a) and side-view (b) diagrams of proposed tapered waveguide for efficient excitation of surface wave (surface plasmon) on dielectric- graphene-dielectric (DGD) structure. 3. Result and discussion The DSD tapered waveguide with magnetic tunability for efficient excitation of surface waves on DGD at terahertz region is proposed and analyzed. Excitation of surface waves on DGD with various chemical potentials in graphene layer and incident frequencies can be attained by merely changing the values of external magnetic field applied onto the DSD tapered waveguide. The FEM electromagnetic simulations verify the design of the proposed structure. More importantly, the constituent materials used in the proposed structure are available in nature. Hence, our methodology can be applied in the field of use of surface waves, such as multi-functional material (device), real-time subwavelength imaging, and high-density optoelectronic components.
[1] S. A. Maier, Plasmonics: Fundamentals and Applications (Springer, New York, 2007). [2] A. Vakil and N. Engheta, “Transformation optics using graphene,” Science 332, 1291–1294 (2011). [3] A. Andryiesuski and A. V. Lavrinenko, “ Nanocouplers for infrared and visible light,” Adv. Optoelectron., 839747 (2012).
170 Oral-38
High Circular Dichroism Ultraviolet Lasing from Planar Spiral Metal-Gallium-Nitride Nanowire Cavity
Min-Hsiung Shih,1,2,3* Wei-Chun Liao2, Shu-Wei Liao2, Kuo-Ju Chen2, Yu-Hao Hsiao2, Cheng-Li Yu2, Shu- Wei Chang1,2, and Hao-Chung Kuo1, 2 1 Research Center for Applied Sciences (RCAS), Academia Sinica, Taipei 11529, Taiwan 2 Department of Photonics and Institute of Electro-Optical Engineering, National Chiao Tung University (NCTU), Hsinchu 30010, Taiwan 3Department of Photonics, National Sun Yat-sen University (NSYSU), Kaohsiung 80424, Taiwan *E-mail address: [email protected] Abstract: 2 } } } ´ µ µ ´ } } ¶ 2 } } } µ } µ } } µ µ } µ ` µ µ } } } } } ´ ` µ µ % ? } ` } ¯ }
171
Session: FRI-R2-S1 FRI-R2-S1
Date: March 25 (Friday) Time: 08:30-10:10 Session Chair: = . ? @ . 0 7 ] ] 7 0 7 Room: 2nd Conference Room (3F) Invited talk
Prof. Manfred Eich
Hamburg University of Technology, Germany.
Tailored thermal emission from refractory March 25, 2016 08:30-09:00 metamaterials 2nd Conference Room (3F)
Biography for Manfred Eich
Director of the Institute of Optical and Electronic Materials, Hamburg University of Technology, Eissendorfer Strasse 38, D-21073 Hamburg, Germany
Co-speaker, member of the board of directors, coordinator of one out of three research areas, and principal investigator (PI) in the DFG Collaborative Research Center SFB 986 “Tailor-Made Multi-Scale Material Systems – M³”
Since 1996 Professor at Institute of Optical and Electronic Materials, Hamburg University of Technology 1998-2004 Foundation and management of UV-Signal GmbH 1991-1996 Scientific staff at Research Center of German Telecom since 1990 SPIE-chair 1989-1997 McKinsey&Co., Inc., Consultant 1987-1989 IBM Research, San Jose, CA, U.S.A. 1987 Doctoral degree in Physics, TH-Darmstadt
Research interests in nanophotonics, high temperature photonics, thermal radiation, silicon photonics, nonlinear optics, organic and polymeric optical materials, optical sensors.
174 IN-32
Tailored thermal emission from refractory metamaterials
M. Eich1, P. N. Dyachenko1, S. Molesky2, M. Störmer4, A. Yu. Petrov1,3, T. Krekeler5, S. Lang1, M. Ritter5, and Z. Jacob2,6 1Institute of Optical and Electronic Materials, Hamburg University of Technology, Eissendorfer Strasse 38, 21073 Hamburg, Germany. 2University of Alberta, Department of Electrical and Computer Engineering,9107 - 116 Street, T6G 2V4, Edmonton, Canada. 3ITMO University, 49 Kronverskii Ave., 197101, St. Petersburg, Russia. 4Institute of Materials Research, Helmholtz-Zentrum Geesthacht Centre for Materials and Coastal Research, Max-Planck-Straße 1, 21502 Geesthacht, Germany. 5Electron Microscopy Unit, Hamburg University of Technology, Eissendorfer Strasse 42, 21073 Hamburg, Germany. 6Birck Nanotechnology Center, School of Electrical and Computer Engineering, Purdue University, West Lafayette, IN 47906,USA E-mail address: [email protected]
Abstract: The control of thermal radiation at high temperatures is mandatory for thermophotovoltaic (TPV) based high efficiency capture of waste heat. Structural resonances utilizing gratings, metasurfaces and photonic crystals can enable or suppress thermal emission in desired spectral windows. Here, however, we present a novel approach to broadband non- resonant intrinsic metallo-dielectric material properties that can be engineered to achieve the desired tailored spectral emissivity. This approach allows suppressing the emission of long wavelength photons which cannot be transformed into electrical power. We demonstrate a high temperature refractory metamaterial which thus bears the potential to increase the efficiency of TPV systems. The near-omnidirectional selective emitter effect arises from an Optical Topological Transition (OTT) in the photonic isofrequency surface. We experimentally demonstrate the thermal topological transition in the metamaterial which is stable at high temperatures of 1000 °C. The aim of this paper is to demonstrate a novel high temperature metamaterial with selective thermal emission arising from an optical topological transition[1] in its photonic isofrequency surface, different from 2D and 3D photonic crystals[2,3], thin film resonances[4], gratings and metasurfaces[5]. Here, we control an intrinsic metamaterial property and bulk thermal energy density to selectively couple thermal radiation to free space modes, thus to tailor far-field thermal emission. The metamaterial is designed based on a subwavelength super- lattice structure with refractory materials tungsten and hafnium oxide. The optical topological transition is carefully designed to lie in the near-infrared window (1 to 3 micron wavelength) paving the way for refractory metamaterials compatible with low bandgap (0.3 to 0.5 eV) TPV-cells. Our design has low angular dependence and is tunable within the entire near-infrared spectrum. Our measurements of the optical absorption and thermal emission at high temperature (1000 °C) serve as a di } ~ R for bulk effective medium parameters. We experimentally demonstrate the high temperature stability of the optical absorption and the thermal emission at 1000 °C and analyze in detail degradation processes occurring at higher temperatures. (a) Designed emissivity charac- teristic of the refractory meta- material. Beyond the transition the metamaterial allows only extraordinary modes with large tangential components of the wavevector, leading to a strong R emissivity. (b) Comparison of the theoretic- cally designed and ellipsometri- cally extracted relative permitti- vity parameters. (c) Schematic image of the refractory metamaterial design. (d) SEM image of the fabricated refractory metamaterial.
[1] Krishnamoorthy, H. N. S., Jacob, Z., Narimanov, E., Kretzschmar, I., and Menon, V. M., Science 336, 205M209 (2012). [2] Chan, D. L. C., So ¶ 6 4 and Joannopoulos, J. D., Opt. Express 14, 8785 (2006). [3] Dyachenko, P.N., do Rosário, J.J., Leib, E.W., Petrov, A.Y., Störmer, M., Weller, H., Vossmeyer, T., Schneider, G.A., and Eich, M., Optics Express 23, A1236 (2015). [4] Narayanaswamy, A., and Chen, G., Phys. Rev. B 70, 125101 (2004). [5] Han, S. E., and Norris, D. J., Opt. Express 18, 4829 (2010).
175 Invited talk
Prof. Lei Zhou
Fudan University, china
Metasurfaces for high-efficiency surface plasmon March 25, 2016 09:00-09:30 coupler and active dispersion compensation 2nd Conference Room (3F)
Biography for Lei Zhou
Zhou, Lei received his PhD in Physics from Fudan University, Shanghai, China, in 1997. He then went to Institute for Material Research in Tohoku University (Sendai, Japan) for postdoctoral research. In 2000 - 2004, he was a visiting scholar in Physics Department of the Hong Kong University of Science and Technology. He joined Physics Department of Fudan University in 2004 as a professor, and became a “Xi-De" Chair Professor since 2013. Starting from 1993, Professor Lei Zhou has been working in the fields of magnetism, meta-materials, photonic crystals and plasmonics, and he has published over 120 papers in scientific journals including Nature Materials, Phys. Rev. X, Phys. Rev. Lett., Nano Lett. He is the co-author of a monograph (Springer) and 3 book chapters. He has successfully held two international conferences in Shanghai, and severed as program committee members or session chairs in many top international conferences, and has been invited to give invited talks in many top international conferences. Professor Lei Zhou got the NSFC "Grant for Outstanding Young Scientist" in 2007 and was entitled "Chang Jiang Scholars Program" Chair Professor in 2009.
176 IN-35
Metasurfaces for high-efficiency surface plasmon coupler and active dispersion compensation
Lei Zhou Physics Department, Fudan University, Shanghai 200433, China E-mail address: [email protected]
Abstract: We present our latest results on metasurfaces, of which one is about a high- efficiency surface plasmon coupler and another is about an active scheme to overcome the dispersion-induced issues in metaurface-based devices.
Surface plasmon polaritons (SPPs), including their low-frequency counterparts (i.e., spoof SPPs on artificial surfaces), have recently found numerous applications in photonics, but traditional devices to excite them (such as grating and prism couplers) all suffer inherent low-efficiency issues, since the generated SPPs can decouple back to free space and the reflection at the device surface can never be avoided. Here, based on a transparent gradient metasurface, we propose a new SPP-excitation scheme and numerically demonstrate that it exhibits inherently high efficiency (~94%), since the designed meta-coupler suppresses both the decoupling and the reflection at its surface. As a practical realization, we fabricate a meta-coupler in the microwave regime, and combine near-field and far-field experiments to demonstrate that the achieved excitation efficiency for spoof-SPP reaches ~73%, which is several times higher than other available devices in this frequency domain. Our findings can inspire the design and realization of high-performance plasmonic devices to harvest light-matter interactions, particularly related to spoof-SPPs in low-frequency domain [1]. On the other hand, metasurfaces realized so far largely reply on passive resonant meta-atoms, whose intrinsic dispersions limit such passive meta- } R performances at frequencies other than the target one. Here, based on active meta-atoms with varactor diodes involved, we establish a scheme to resolve these issues for microwave metasurfaces, in which the dispersive response of each meta-atom is precisely controlled by an external voltage imparted on the diode. We experimentally demonstrate two effects utilizing our scheme. First, we show that an active gradient metasurface exhibits single-mode high-efficiency operation within a wide frequency band, while its passive counterpart only works at a single frequency but exhibits deteriorated performances at other frequencies. Second, we demonstrate that the functionality of our metasurface can be dynamically switched from a specular reflector to a surface-wave convertor. Our approach paves the road to achieve dispersion-corrected and switchable manipulations of electromagnetic waves, and a dynamically controlled aberration-free flat-lens focusing is experimentally demonstrated here as an example of many possible applications [2].
Figure 1. Characterizations on the microwave meta-coupler.
[1] Wujiong Sun, et al. "High-efficiency Surface Plasmon Meta-couplers: Concept and Microwave-ġġġregime realizations "Light: Science & Applications 5, 16003 (2016). [2] He-Xiu Xu, et al., Active microwave metasurfaces for high-performance operations: dispersion ġ compensation and dynamical switchP, Unpublished.
177 Oral-36
Fabrication of Titanium Nitride as Plasmonic Materials with Room Temperature High-power Impulse Magnetron Sputtering
Kuo-Ping Chen and Zih-Ying Yang U " B " S U & U
Abstract: Justify the paragraph (on both right and left), and use 10-point Times New Roman font. Your abstract should state the problem, the methods used, the major results and conclusions.
1. Introduction Low loss alternatives plasmonic materials like titanium nitride (TiN), have received significant interests in recent years [1]. TiN has low loss in the visible and NIR wavelengths and the optical properties can be adjusted that TiN is expected to serve as the alternative plasmonic material in visible and near® infrared wavelengths rather than gold and silver [2]. Reactive sputtering deposition is commonly used to deposit nitride films because the composition of the film can be controlled by varying the relative pressures of the inert and reactive gases. In past decades, the development of reactive high power impulse magnetron sputtering (HiPIMS) technology has got lots of attention due to not only better performance of compound deposited films but also more smooth and denser films [3, 4]. In this study, TiN thin films were deposited on B270 glass by HiPIMS with DC®® RF co sputtering system at 400 °C. First, the effects of power density parameter on the conductivity and optical resonant properties of the TiN thin film will be investigated. Then, the relationship between electrical and optical properties will be shown. Figure 1 shows the measured dielectric function and measured sheet resistance for HiPIMS 45/955, HiPIMS 45/45, and DC samples. When using HiPIMS technique, the denser film can be fabricated, which contains higher carrier concentration per unit volume, and the corresponding resonance wavelength will appear at a shorter wavelength. In addition, the experimental sheet resistance’s relations between each sample are in good agreement with the theoretical resistivity. Compared to the HiPIMS samples, the DC sample shows poor performance, that the dielectric function over the near-infrared range exhibits obviously slowed-down slope due to the accumulated charge on the target. If the HiPIMS on/off ratio is <10% (HiPIMS 45/955), the dielectric function exhibits more metal- like behaviors, and the resistivity decreases significantly. D E F
Figure 1. TiN dielectric function using various on/off ratio (a) Real part and (b) imaginary part. Electrical properties of TiN thin-films using various on/off ratio (c) sheet resistance.
[1] A. Boltasseva and H. A. Atwater, "Low-loss plasmonic metamaterials," Science, 2011. [2] J. B. Khurgin and A. Boltasseva, "Reflecting upon the losses in plasmonics and metamaterials," MRS bulletin, vol. 37, pp. 768-779, 2012. [3] C.-L. Chang et al "Effect of duty cycles on the deposition and characteristics of high power impulse magnetron sputtering deposited TiN thin films," Surface and Coatings Technology, 2014. [4] Zih-Ying Yang, Yi-Hsun Chen, Bo-Huei Liao, and Kuo-Ping Chen, "Room temperature fabrication of titanium nitride thin films as plasmonic materials by high-power impulse magnetron sputtering," Opt. Mater. Express 6, 540-551 (2016)
178 Oral-39
Lattice Light Sheet Microscopy: From Molecules to Organism Imaging
Bi-Chang Chen Research Center for Applied Science, Academia Sinica 128 Academia Road, Section 2, Nankang, Taipei 11529, Taiwan E-mail address: [email protected]
Abstract: Optical imaging techniques are important and informative to improve scientist’s understanding of life science and to tackle biological problems of interest. It is desirable to acquire a tool that is capable of watching molecular level processes that are going on in biological system, especially in vivo. Although fluorescence microscopy provides a crucial window into the physiology of living specimens, many biological processes are too fragile or occur too rapidly and on too small a scale to see clearly with existing tools. We crafted ultra-thin light sheets derived from two-dimensional optical lattices that allowed us to image three- dimensional (3D) dynamics for hundreds of volumes, often at sub-second intervals, at the diffraction limit and beyond. We applied this tool to systems spanning four orders of magnitude in space and time, including the diffusion of single transcription factor molecules in a spheroid of stem cells, the 3D dynamic instability of microtubules during mitosis, the formation of the immunological synapse, neutrophil motility in a 3D matrix, and embryogenesis in Caenorhabditis elegans and Drosophila melanogaster. The results provide a visceral reminder of the beauty and complexity of living systems, where stereotypical processes arise from stochastic events.
References [1] BC Chen et al., Science, 346, 1257998 (2014). [2] L Gao et al., Nature protocols , 9,1083-1101 (2014). [3] L Gao et al., Cell, 151, 1370-1385 (2012). [4] T Planchon, et al., Nature methods, 8, 417-423 (2011).
179
Session: FRI-IC-S2
Date: March 25 (Friday) Time: 10:30-12:10 Session Chair: 1 . . 0 7 FRI-IC-S2 ? . 7 . . R . % ? 1 Room: Invited talk
Prof. Mu Wang
Nanjing University, China
An Approach to Tune the Polarization State of Light March 25, 2016 10:30-11:00 with Metastructures over a Broad Frequency Range International Conference Hall (4F)
Biography for Mu Wang
Mu Wang received his BS in 1984 and PhD in 1991 both from Nanjing University, China. He did postdoctoral research at Nijmegen University, the Netherlands during 1992-94. He received Chien-Shiung Wu Physics Award from the Chinese Physical Society in 1992 and the Distinguished Young Scholar Fund from NSF of China in 1994. As an experimental physicist, His research interests focus on the fundamentals of interfacial growth and optical properties of microstructured materials. He is particularly interested in finding out the mechanisms of spatio- temporal oscillations in crystallization, applying these effects to self-organize metallic and oxide microstructures with tunable periodicity, and pinpointing the novel opto-electric properties of these microstructures.
He was elected as the IOP Fellow (UK) (2004) and APS Fellow (2012). He served as the member of the Standing Committee, the Council of Chinese Physical Society 2004-2015, and has been a member of the Commission on Structure and Dynamics of Condensed Matter (C10) of the International Union of Pure and Applied Physics since 2011. He was the Director of National Laboratory of Solid State Microstructures at Nanjing University during 2006-2014. He is currently the Cheung-Kong Professor at Nanjing University and is the Associate Editor of Physical Review Letters since 2014.
182 IN-36
An Approach to Tune the Polarization State of Light with Metastructures over a Broad Frequency Range
Mu Wang*, S. C. Jiang, X. Xiong, R. W. Peng
(" (Corresponding author, [email protected])
Abstract: Controlling the polarization state, the transmission direction and the phase of light within a confined space is an important issue in optics. When the surface plasmon is excited on metallic surface, the surrounding electromagnetic field will be modulated due to the irradiation of oscillating surface electric current. At the resonant frequency this effect is so significant that a thin layer of metallic structure can effectively tune the state of light. However, the underlying Lorentz resonance in metal is highly dispersive in nature, which limits its application to a specific narrow frequency range. On the other hand, the dielectric material interacts with light by accumulating optical path within a certain thickness. This feature is effective over a broad bandwidth, and has already been applied in antireflection coating and other optical devices. By integrating metallic metastructure and dielectric interlayer, it is possible to realize the dispersion-free broadband device on sub-wavelength scale, where the strong response of the metallic structures helps to decrease the device size while the dielectric interlayer helps to eliminate the dispersion simultaneously in both the amplitude and the phase difference of the reflected/transmitted light [1].
As an examples to apply this concept, a broadband quarter-wave plate and a half-wave plate are experimentally demonstrated. By carefully selecting the structural parameters, the polarization state of light can be freely tuned across a broad frequency range, and all of the polarization states on the Poincaré sphere can be realized dispersion free [1-3]. Further, this principle is applied to construct a broadband metasurface devices that is able to turn either a linearly polarized incident light or natural light into two perfect circularly polarized beams with the same amplitude yet different handiness to different directions. This feature provides a clear example of momentum conservation, and can be applied to detect/manipulate the propagation of circularly polarized light [4].
References: [1] S.-C. Jiang, X. Xiong, Y.-S. Hu, Y.-H. Hu, G.-B. Ma, R.-W. Peng, C. Sun, and Mu Wang*, A , Physical Review X 4, 021026 (2014) [2] S.-C. Jiang, X. Xiong, P. Sarriugarte, S.-W. Jiang, X.-B. Yin, Y. Wang, R.-W. Peng, D. Wu, R. Hillenbrand, X. Zhang, and Mu Wang*, U Physical Review B 88, 161104(R) (2013) [3] X. Xiong, Y.-S. Hu, S.-C. Jiang, Y.-H. Hu, R.-H. Fan, G.-B. Ma, D.-J. Shu, R.-W. Peng, and Mu Wang*, Applied Physics Letters 105, 201105 (2014) [4] S C. Jiang, X. Xiong, Y.-S. Hu, S.-W. Jiang, Y.-H. Hu, D.-H. Xu, R.-W. Peng*, Mu Wang*, C Physical Review B 91, 125421 (2015)
Keywords: metasurface, surface plasmon polariton, metallic nanostructures, polarization of light, wave plates.
183 Invited talk
Prof. Jr-Hau He
King Abdullah Univ. of Science & Technology, Saudi Arabia
Photon managements by employing March 25, 2016 11:00-11:30 nanostructures for optoelectronic devices International Conference Hall (4F)
Biography for Jr-Hau He
Dr. Jr-Hau He is an Associate Professor of Electrical Engineering program at King Abdullah University of Science & Technology (KAUST). He was a Visiting Scholar at Georgia Tech (2005), a Postdoc Fellow at National Tsing Hua University (2006) and Georgia Tech (2007), a Visiting Professor at Georgia Tech (2008), UC Berkeley (2010 and 2014), and UC San Diego (2012-2013), and HKPolyU (Dec. of 2014), and a tenured Associate Professor at National Taiwan University (2007-2014).
His work encompasses a broad, multidisciplinary field, borrowing from electrical, physics, chemical and materials science and engineering to understand the effects of nanomaterials on the performance of advanced devices. He devotes his efforts in the development of transparent and flexible electronics using novel devices based on nanomaterials, including solar cells and photodetectors, LEDs, and memory devices. He is also interested in harsh electronics. His particular interest in solar energy include efforts to understand light scattering and trapping in nanostructured materials and designs for next-generation solar cells. He is also interested in transport of charge carriers across these solar cells as well as the improvement in light coupling with the combined effect to increase the efficiency of separating the photoinduced charges. Dr. He’s group is also currently involving in fundamental physical properties of nanomaterials, such as the transport and switching behavior of 2D nanomaterials. He emphasizes the transfer of the nanotechnology he developed to semiconductor and PV industry. Dr. He served as Accreditation Council of “Republic of China fine manufacturer association” to advise small and medium-sized enterprises to have innovation and product features in the marketplace.
He has garnered over 5300 citations for a body of work consisted of ~150 peer reviewed journal articles with 39 of H factor over his career and over 200 presentations in international conferences. His breakthrough researches have been highlighted over 50 times by various scientific magazines such as Nature, SPIE newsroom, IEEE SPECTRUM, EE Times, Semiconductor Today, Materials Today, Chemical & Engineering News, and Nano Today.
Visit his web for more information (nanoenergy.kaust.edu.sa).
184 IN-39
"! ! < @ & Computer, Electrical and Mathematical Sciences and Engineering (CEMSE) Division, King Abdullah University of Science & Technology (KAUST) Email: [email protected] It is of current interest to develop the photon management with nanostructures since the ability to suppress the reflection and light trapping over a broad range of wavelengths and incident angles plays an important role in the performance of optoelectronic devices, such as photode- tectors, light-emitting diodes, optical components, or photovoltaic systems.[1-7] Superior light-trapping characteristics of nanowires, including polarization-insensitivity, omnidirec- tionality, and broadband working ranges are demonstrated in this study.[8-10] These ad- vantages are mainly attributed to the subwavelength dimensions of the nanowires, which makes the nanostructures behave like an effective homogeneous medium with continuous gradient of refraction index, significantly reducing the reflection through destructive interfer- ences. The relation between the geometrical configurations of nanostructures and the light-trapping characteristics is discussed. We also demonstrated their applications in solar cells and photodetectors. This research paves the way to optimize the nanostructured optoe- lectronic devices with efficient light management by controlling structure profile of nanostructures.
; < [1] H. P. Wang, T. Y. Lin, C. W. Hsu, M. L. Tsai, C. H. Huang, W. R. Wei, M. Y. Huang, Y. J. Chien, P. C. Yang, C. W. Liu, L. J. Chou and J. H. He, ACS Nano, 2013, 7, 9325. [2] C. R. Ho, M. L. Tsai, H. J. Jhuo, D. H. Lien, C. A. Lin, S. H. Tsai, T. C. Wei, K. P. Huang, S. A. Chen and J. H. He, Nanoscale, 2013, 5, 6350. [3] H. C. Chang, K. Y. Lai, Y. A. Dai, H. H. Wang, C. A. Lin and J. H. He, Energy Environ. Sci., 2011, 4, 2863. [4] L. K. Yeh, K. Y. Lai, G. J. Lin, P. H. Fu, H. C. Chang, C. A. Lin and J. H. He, Adv. Energy Mater., 2011, 1, 505. [5] K. Y. Lai, H. C. Chang, Y. A. Dai and J. H. He, Opt. Express, 2012, 20, A255. [6] Y. H. Hsiao, C. Y. Chen, L. C. Huang, G. J. Lin, D. H. Lien, J. J. Huang and J. H. He, Nanoscale, 2014, 6, 2624M2628. [7] C. Y. Hsu, D. H. Lien, S. Y. Lu, C. Y. Chen, C. F. Kang, Y. L. Chueh, W. K. Hsu and J. H. He, ACS Nano, 2012, 6, 6687M6692. [8] H. P. Wang, D. H. Lien, M. L. Tsai, C. A. Lin, H. C. Chang, K. Y. Lai and J. H. He, J. Mater. Chem. C, 2014, 2, 3144M 3171. [9] H.P. Wang, T.Y. Lin, M.L. Tsai, W.C. Tu, M.Y. Huang, P.C. Yang, Y.J. Chien, C.W. Liu, Y.L. Chueh, and J.H. He, ACS Nano 2014, 8, 2959-2969. [10] W.R. Wei, M.L. Tsai, S.T. Ho, S.H. Tai, C.R. Ho, S.H. Tsai, C.W. Liu, R.J. Chung, J.H. He, Nano Lett. 2013, 13, 3658-3663.
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Enhanced Coherent Light Emission Properties in Solution-processed Lead Halide Perovskites
Tsung Sheng Kao1, Yu-Hsun Chou2, Kuo-Bin Hong1, Jiong-Fu Huang1, Fang-Chung Chen1,*, and Tien-Chang Lu1, 1Department of Photonics and Institute of Electro-Optical Engineering, National Chiao Tung University, Hsinchu 30010, Taiwan 2Institute of Lighting and Energy Photonics, College of Photonics, National Chiao Tung University, Tainan 71150, Taiwan E-mail address: [email protected]; [email protected]
Abstract: In this paper, a simple method for promoting the coherent light emission properties of the lead-halide perovskite has been demonstrated. With the covered PMMA and Ag thin films, the perovskites can be protected from hydrolysis and feasibly performed in ambient environment with reduced lasing thresholds.
Introduction Recent studies have demonstrated that the photoluminescence (PL) quantum efficiencies of the hybrid metal-halide perovskites exceed 70% and the lasing behavior in various perovskite films shows an emission wavelength tunability at different halide compositions. These advanced promising results make the perovskites as alternative materials for the light emission applications in efficient on-chip coherent light sources and white-light light-emitting diodes.[1,2] However, the hydrolysis of perovskites in ambient environment is still one of the most critical challenges and may hamper the perovskites in practical application. In this work, we exploit a transparent thermoplastic layer of polymethylmethacrylate (PMMA) capped onto the as-prepared perovskite layer to prevent the sample damages from the hydrolysis. Furthermore, a continuous silver (Ag) thin film was evaporated on the samples, promoting the light emission properties with enhanced plasmonic fields.
Results and Discussions Figure 1(a) shows the schematic layer structure of the solution-processed perovskite CH3NH3PbI3 capped with a layer of transparent PMMA and an Ag thin film. To prepare the lead halide perovskites, a relatively simple two-steps solution process was employed. Then, the PMMA was spin-coated onto the prepared perovskite layers with corresponding thickness. With the PMMA layer, the perovskites can be protected from the hydrolysis in ambient environment. At the end, a 20 nm thin film of Ag material was evaporated onto the PMMA layer. Fig. 1(b) displays the coherent light emission characteristics of the perovskite films at a low temperature of 77 K. The thickness of the PMMA layer is about 20 nm. Under low optical power excitations, only very broad spontaneous emission spectra can be observed at the spectral centers of around 753 nm. With a gradually increased pumping powers, the emission intensity increases dramatically as the excitation power ) The significant peak width at full width at half maximum (FWHM) reduced to about 3 nm. Since there is no specifically defined laser cavities in the perovskite films, the optical feedback for lasing could be formed via random scattering provided by the polycrystalline grain boundary and/or phase separation.[2] The lasing performance of perovskites with different PMMA thicknesses is demonstrated in Fig. 1(c). Compared with the lasing thresholds of the bare perovskites, the threshold power can be dramatically reduced even more than an order with the capped PMMA and Ag thin layers. The improved threshold power may result from the spacer generation between the Ag thin film and perovskites, producing an enhanced plasmonic field. The capped PMMA and Ag thin films not only enhance the coherent light emission properties with a reduced threshold power, but also provide the promising potentials in realizing the practical perovskites optoelectronic devices.
(a)excitation beam (b) (c) 260 = 355 nm 753 nm 12 )W 240 Perovskite only, Pth~250 W W)
$ $ $ $ 80
60 without PMMA FWHM ~ 3 nm 40
Perovskite Optical pumping
(CH3NH3PbI3) Peak intensity (a.u.) 20 3 )W Threshold power( 0 730 740 750 760 770 50 150 250 350 Wavelength (nm) PMMA thickness (nm) Fig.1 (a) Schematic layer structure of the lead halide perovskite covered with a PMMA layer and an Ag thin film layer. (b) Lasing characteristics of the perovskite films with PMMA of 20 nm at the temperature of 77 K. (c) Threshold power of the perovskites covered with a PMMA layer at different thicknesses.
References [1] G. Xing, N. Mathews, S. S. Lim, N. Yantara, X. Liu, D. Sabba, M. Gratzel, S. Mhaisalkar, and T. C. Sum, 1 -temperature solution-processed wavelength- } Nature Mater. 13, 476 (2014) [2] T. S. Kao, Y. -H. Chou, C. -H. Chou, F. -C. Chen, and T. -2 1 1 } in solution- } Appl. Phys. Lett. 105, 231108 (2014)
186 Oral-43
Tailoring Optical Responses of Glass Using Silver Nano- Pillars for Saving Energy
Chi-Chun Ho, Yu-Bin Chen*, and Fu-Yuan Shih F S U & U
Abstract: Periodically-isolated and metallic nano-structures are shown to tailor dual optical responses within a broad band. Embedded silver nano-pillars successfully manipulate reflectance and transmittance through glass (SiO2) from the ultraviolet to near-infrared. The rigorous coupled-wave analysis and genetic algorithm are integrated into numerical programs to optimize dual property spectra for energy-saving. The performance of two examples is also quantitatively demonstrated based on ISO 9050 at the incidence of transverse electric and transverse magnetic waves. Physical mechanisms responsible for tailored spectra are explained using dispersion curves and electromagnetic field patterns.
1. Introduction Advances in nano-technology have largely facilitated the development of energy-conversion and energy- saving devices [1]. However, not every type of nano-structures was popular for tailoring optical responses in a broad band. Periodically-isolated and metallic pillars were much more appealing to manipulate narrow-band responses because those structures facilitated localized resonances. The excitation of a resonance mode usually leads to a sharp dip in S spectrum, and the dip is very attractive to sensors for its high sensitivity [2]. As a result, energy-related devices using broadband tailored properties generated by metallic nano-pillars were rarely explored. The objective of our work is to seek the possibility of tailoring broadband optical responses using metallic pillars with uniform profile and periodic alignment. Two optical responses (S and U) will be simultaneously tailored from ultraviolet (UV) to near-infrared (near-IR). The S will be expected to low in visible (VIS) range, but it will be enlarged in UV and near-IR. On the other hand, the U in VIS shall be kept high, but it will be reduced in UV and near-IR. This way, expenses for indoor illumination and air- conditioning can be saved, particularly in a hot sunny day. People and furniture will not be harmed by UV light, while outdoor drivers and passengers will not suffered from reflected stray light. These wavelength- selective properties will be both plotted and quantitatively compared based on the international standard ISO 9050 [3]. Physical mechanisms contributing to unique features in spectra are going to be explained with electromagnetic (EM) field patterns and dispersion curves.
2. Figures and tables
Fig. 1. The S and U of s = 1710 nm, ³ = 250 nm, = 0.11, and = 400 nm) at the normal incidence of: (a) TM waves; (b) TE waves.
3. References [1] E. Serrano, G. Rus, J. Garcia-Martinez, Renew. Sustainable Energy Rev. 13, 2373-2384 (2009). [2] K.M. Mayer, J.H. Hafner, Chem. Rev., 111, 3828-3857 (2011). [3] http://standards.globalspec.com/std/157817/iso-9050
187
Session: FRI-R1-S2
Date: March 25 (Friday) Time: 10:30-12:10 Session Chair: < . < . ? . 7 ? 7 R . . % % ? 1 Room: 1st Conference Room (3F) FRI-R1-S2 Invited talk
Prof. Hui Liu
Nanjing University, China
March 25, 2016 Mimicking Einstein’s Ring in Curved Waveguides 10:30-11:00 1st Conference Room (3F)
Biography for Hui Liu
Hui Liu, Professor at Nanjing University. Hui Liu received his Ph.D. in 2003. In 2004-2005 he did postdoctoral research at University of California at Berkeley. His research interest includes coupled metamaterials, photonic black hole in transformation optics and plasmonic spin-hall effects. He has published over 70 SCI papers, including Nature Photonics 7, 902 (2013); Nature . 6 ` 6 .7 8 08 8 (2011); Phys. Rev. Lett. 97, 243902 (2006).
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Mimicking Einstein s Ring in Curved Waveguides
Chong Sheng1, Rivka Bekenstein2, Hui Liu1,*, Shining Zhu1 and Mordechai Segev2,* R (" U " C 0
Abstract: We propose wavefront shaping by exploiting General Relativity effects and concepts of curved space in waveguide settings. We use this technique to construct a very narrow non-diffracting beam and also design shape-invariant accelerating beams propagating along arbitrary trajectories. Finally, we demonstrate the phenomenon of R 0 R ?
The fact that the propagation of EM waves in static curved space is analogous to that in inhomogeneous media is the underlying principle of emulating General Relativity (GR) phenomena [1-2]. In artificial structures, the refractive indexs are structured to vary according to the curvature of space, giving rise to unique trajectories and controlling the diffraction of light [3-5]. Here, we show that using ideas inspired by GR yields efficient beam shaping in waveguide settings (figure (a)) [6]. First, we fabricate the micro-structured optical waveguide with the specific refractive index emulating the curved space environment generated by a massive gravitational object. This dielectric structure yields a very narrow beam that remains non-diffracting for many Rayleigh lengths (figure (b)). Second, with R R old formula (figure (d)). Finally, we present a general formalism to transform broad Gaussian beams to shape- invariant beams accelerating (bending) along arbitrary trajectories (figure (b)). The concept is general, applicable to many cases where wavefront beam shaping in a waveguide platform is required.
Figure (a) Curved space in general relativity; (b) Accelerating Beam in curved space; Wavefront shaping in our experiment: (c) Collimated beam and (d) Einstein ring.
[1] A. Einstein, "Lens-like action of a star by the deviation of light in the gravitational field," Science 84, 506 (1936). [2] U. Leonhardt and T. G. Philbin, "General relativity in electrical engineering," E 8, 247 (2006). [3] C. Sheng et al., "Trapping light by mimicking gravitational lensing," 7, 902 (2013). [4] R. Bekenstein , "Shape-Preserving Accelerating Electromagnetic Wave Packets in Curved Space," S Y 4, 011038 (2014). [5] R. Bekenstein gravitational effects in the NewtonM 11, 872 (2015) [6] C. Sheng, R. Bekenstein } 2 } , in revision (2015)
191 Invited talk
Prof. Greg Sun
University of Massachusetts Boston, USA
Ge/Ge Sn /Ge p-i-n Photodetector March 25, 2016 0.975 0.025 11:00-11:30 Operated with Back-side Illumination 1st Conference Room (3F)
Biography for Greg Sun
Greg Sun received his B.S. in Microelectronics from Peking University in 1984, M.S. in Electrical Engineering from Marquette University in 1988, and Ph.D. in Electrical Engineering from Johns Hopkins University in 1993. Since then, he joined the faculty at the University of Massachusetts Boston where he currently is a Professor of Electrical and Computer Engineering. His research efforts focus on theoretical investigations in semiconductor optoelectronics and nanophotonics. His research efforts focus on theoretical investigations in semiconductor optoelectronics and nanophotonics. He has published over 110 papers in refereed journals. He has delivered over 100 invited and contributed conference papers, and given over 40 seminars and colloquia. He serves on various conference committees and on the editorial board of a technical journal. He led the effort at UMass Boston in establishing the Department of Engineering – the only publically supported Engineering education in Boston area and is currently serving as its founding chair.
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Ge/Ge0.975Sn0.025/Ge p-i-n Photodetector Operated with Back-side Illumination
C. Chang1, H. Li1, S. H. Huang1, H. H. Cheng1, and G. Sun2,* 1 Center for Condensed Matter Sciences and Graduate Institute of Electronics Engineering, National Taiwan University, Taipei, 106, Taiwan, R. O. C. 2 Department of Engineering, University of Massachusetts Boston, Boston, Massachusetts 02125, USA. *E-mail address: [email protected]
Abstract: We report an investigation of a GeSn-based p-i-n photodetector grown on a Ge wafer that collects light signal from the back of the wafer. This investigation demonstrates the feasibility of a GeSn-based photodiode that can be operated with back-side illumination for applications in image sensing systems.
1. Introduction The group IV element Ge has been widely used for optical sensors operating in the near infrared region [1]. In a recent development, Sn, another group IV element is incorporated into the Ge, narrowing the bandgap of the Ge host material [2]. This gives rise to the widening of detection range to the middle infrared, thus expanding the range of applications. A photodiode fabricated with a GeSn-based p-i-n structure (Ge/GeSn/Ge) grown on a Si wafer has been demonstrated [3]. These photodiodes are front illuminated, collecting light from the surface of the sample, and the absorption spectra show that the detection range extends to lower energy depending on the Sn compositions. For image sensing systems such as structures composed of focal plane diode arrays, the top front ends of these diodes are used for the electrical contacts that connect to the read-out circuit for signal processing, as a result, front illumination is no longer an option, back-illuminated photodiodes that collect the light signal from the back-side of the wafer are required. Here, we report an investigation of a GeSn-based p-i-n photodiode grown on a Ge wafer that is operated with back- side illumination.
2. Sample Structure and Measurement The GeSn-based p-i-n photodiode was grown by solid-source molecular beam epitaxy on an n-type Ge (001) wafer with a resistivity of 1-cm as shown in Fig.1(a) where the structure consists of: (a) undoped layers of Ge/GeSn/Ge with thicknesses of 15/160/15 nm, (b) a p-type Ge layer with a doping concentration of 1 × 1018 cm-3 and a thickness of 90 nm. The sample was fabricated into a diode structure with a rectangular mesa (0.5mm×1.5mm) etched down to the n-type Ge wafer using dry reactive ion etching. The I-V trace measured at room temperature in a dark environment is plotted in Fig. 1(b). It shows a diode-like behavior with a current density of ~10-3 A/cm2 at an applied voltage of -0.5 V. Absorption measurements were performed using a high intensity tungsten lamp as the light source, and the photocurrent was recorded with the AC detection technique. The selected monochromatic light was then focused onto the sample placed inside of a cryostat. The temperature dependent spectral response of the sample is depicted in Fig. 1(c).
Fig. 1. (a) Transmission electron microscopy high angle annular dark field image of the sample. (b) J-V characteristics of the photodiode measured in a dark environment. (C) Spectral responsivities of the photodiode, measured at a range of temperatures from room temperature to 25 K.
3. Conclusion A GeSn-based p-i-n photodiode operated with back-side illumination has been demonstrated. The detection starts at the direct bandgap of the GeSn layer and continues up to the direct bandgap of the Ge wafer.
[1] Y. Ishikawa and K. Wada, IEEE Photonics J. 2, 306 (2010). [2] M. Oehme, E. Kasper, and J. Schulze, ECS J. Solid State Sc. 2, R76 (2013). [3] Y. H. Peng, H. H. Cheng, V. I. Mashanov, and G. E. Chang, Appl. Phys. Lett. 105, 231109 (2014).
193 Oral-41
Pulsed and CW adjustable 1942nm single-mode all-fiber Tm-doped fiber laser system for surgical laser soft tissue ablation applications
Yize Huang1, Jamil Jivraj1, Jiaqi Zhou2, Joel Ramjist1, Ronnie Wong1, Xijia Gu2, and Victor X. D. Yang1,3,4,5,* 1Biophotonics and Bioengineering Laboratory, Department of Electrical and Computer Engineering, Ryerson University, 350 Victoria St., Toronto, Ontario M5B 2K3, Canada 2Fiber Optic Communication and Sensing Laboratory, Department of Electrical and Computer Engineering, Ryerson University, 350 Victoria St., Toronto, Ontario M5B 2K3, Canada 3Division of Neurosurgery, Faculty of medicine, University of Toronto, 27 King's College Cir., Toronto, Ontario M5S 1A1, Canada 4Division of Neurosurgery, Sunnybrook Health Sciences Centre, 2075 Bayview Ave, Toronto, Ontario M4N 3M5, Canada 5Physical Sciences Program, Sunnybrook Research Institute, 2075 Bayview Ave, Toronto, Ontario M4N 3M5, Canada *[email protected]
Abstract: A surgical laser soft tissue ablation system based on an adjustable 1942nm single-mode all-fiber Tm-doped fiber laser operating in pulsed or CW mode with nitrogen assistance is proposed. Ex vivo ablation on soft tissue targets such as muscle (chicken breast) and spinal cord (porcine) with intact dura are performed at different ablation conditions to examine the relationship between the system parameters and ablation results. The maximum laser average power is 14.4W, and its maximum peak power is 133.1W with 21.3) energy. The maximum CW power density is 2.33×106W/cm2 and the maximum pulsed peak power density is 2.16×107W/cm2. The system parameters examined include the average laser power, CW or pulsed operation mode, gain-switching frequency, total ablation exposure time, and the input gas flow rate. The ablation effect was measured by microscopy and optical coherence tomography (OCT) to evaluate the ablation depth, superficial heat- affected zone diameter (HAZD) and charring diameter (CD). Our results show that the system parameters can be tailored to meet different clinical requirements such as ablation for soft tissue cutting or thermal coagulation for future applications of hemostasis. ©2016 Optical Society of America OCIS codes: (170.0170) Medical optics and biotechnology; (170.1020) Ablation of tissue; (140.3510) Lasers, fiber; (110.4500) Optical coherence tomography.
194 Oral-44
Line-shapes of WGM enhanced photoluminescence spectra of ZnO microspheres with exciton-polariton effect
Ching-Hang Chien 1,2,3 , Buu Trong Huynh Ngo,1,2,3 and Yia-Chung Chang 1,4,*1 1Research Center for Applied Sciences, Academia Sinica, Taipei, 11529, Taiwan 2Nano Science and Technology Program, TIGP, Academia Sinica, Taipei 11529, Taiwan 3Department of Engineering and System Science, National Tsing Hua University, Hsinchu 30010, Taiwan 4Department of Physics, National Cheng Kung University, Tainan 701, Taiwan E-mail address: X 6 Abstract: We propose a theoretical model to analyze the line shape of WGM (whispering gallery mode) enhanced PL (photoluminescence) of ZnO microsphere and compare with experimental results [1]. We adopt a model [2] which simplifies HopfieldRs coupled equations [3-4] from the full quantum mechanical picture into a semi-classical picture. We then apply this method to explain how absorption and emission occurred in ZnO microsphere cavity. The coupled Schordinger and Maxwell equations describe the behavior of exciton-polariton composite particle well. [1] Polarization field P describes the exciton and electric field E characterizes the photon. Our method can provide a good description not only for the peak position but also the line-shape of the emission spectrum. Including the polariton effect gives better prediction of the peak positions in the UV range. We found that the WGM peaks only exist on the low-energy side of exciton PL peak, because they are derived from the lower branch of the exciton polariton. Adding a Gaussian-shape background for the visible emission, we also obtain excellent fit to the line-shapes of WGM modes in the visible. Based on our theoretical analysis, we found that the ZnO microsphere provides significant conversion of emission from UV to visible due to the cavity effect. Our theoretical studies can provide useful guidelines for the design of microelectronic devices for visible optical communication based on microspheres.
[1] R. S. Moiranhthem. "Optical cavity modes of a Single Zinc Oxide Microsphere." Optics Express 21, 3010-3020 (2013). [2] M. Chen, Y.-C.Chang, and W.-F. Hsieh, "Finite-difference time-domain analysis for the dynamics and diffraction of exciton-polaritons," J. Opt. Soc. Am. A 32, 1870-1875 (2015). [3] J. J. Hopfield. "Theory of the contribution of excitons to the complex dielectric constant of crystals." Phys. Rev. 112, 1555(1958). [4] J. J. Hopfield. Resonant scattering of polaritons as composite particles. Phys. Rev. 182, 945(1969).
195
Session: FRI-R2-S2
Date: March 25 (Friday) Time: 10:30-12:10 Session Chair: Lei Zhou (Fudan University, china) R] ] ` ? ] 0 7 ? . 7 ? 1 Room: 2nd Conference Room (3F) FRI-R2-S2 Invited talk
Prof. Masanobu Haraguchi
Tokushima University, Japan
Polymer core channel plasmonic waveguide for March 25, 2016 10:30-11:00 Si-Plasmon hybrid photonic integrated circuit 2nd Conference Room (3F)
Biography for Masanobu Haraguchi
Prof. Dr Masanobu Haraguchi was born in 1962. He received his bachelor and master degrees in electronic engineering from Osaka University. He was received the Ph. D. degree from the Osaka University in 1993. From 2009, he is a Professor at Tokushima University. He is interested in characteristics and applications of localized and propagating surface plasmon polaritons (SPPs) at nano metal structures. He is working on the research areas of SPPs and of optical evaluation for semiconductors from 1987 with Prof. Fukui in Tokushima University. Recent his main interests are channel-type plasmonic waveguides, their application and a sprit ring resonator fabricated by nanosphere lithography for near infrared and visible region.
198 IN-38
Polymer core channel plasmonic waveguide for Si- Plasmon hybrid photonic integrated circuit
Masanobu Haraguchi, Koji Okuda, Shun Kamada and Toshihiro Okamoto Department of Optical Science and Technology, Graduate School of Tokushima University, JAPAN [email protected]
Abstract: We have established a fabrication process to fabricate Si-Plasmonic hybrid photonic integrated circuit. PMMA fin patterned by electron beam lithography are employed as core of the plasmonic waveguide. We have experimentally demonstrated the junction of Si-Plasmonic waveguide of which characteristics agree with those by numerical simulation.
1. Introduction Channel plasmonic waveguides (CPWs) may provide a small mode diameter of the propagating mode, beyond the diffraction limit of the light. They, therefore, are expected to realize tiny devices and ultra high- density optical integrated circuits [1,2]. For such the circuits, we have to establish device designs to overcome the optical loss in metals and a suitable fabrication process with low defects. It looks like a nice approach to employ a combination of Si-wire waveguide and CPW[2], i.e., hybrid photonic circuits, because that Si waveguide can support a long enough propagation length to transfer the optical energy to some devices inside a chip. Moreover we can apply the various Si lithography techniques to fabrication such the hybrid circuits. Although some groups have already demonstrated such the hybrid photonic circuit structures [2,3] but there are still some gap to realize the integrated circuit. In this presentation, we have proposed the fabrication process to make a Si wire-CPW hybrid circuits. We have employed a PMMA fin structure as the core of CPW, which provides us a gap and trench plasmonic waveguides with low defect, waveguide bends with low loss and a low loss junction between Si-wire waveguide and CPW.
2. Requirement of plasmonic waveguide and Fabrication process In order to fabricate a high density circuit, characteristics of CPWs are required the following three things: low light intensity outside CPW to prevent unintentional cross talk, low scattering loss at the sharp bend to provide compact area size of circuit, and the high compatibility fabrication process with current Si nano lithography process. We, therefore, employed Gap and Trench plasmonic waveguide with a polymer core of a subwavelength width and a wavelength height as CPWs satisfied the above requirements. Such the dimension of the CPW provide the propagating plasmon modes of which energy is confined inside the CPW structure and low scattering loss at bend structure. In our fabrication process, we applied electron-beam (EB) lithography technique to fabricate our hybrid photonic circuit with high density on a SOI substrate.
3. Example of structure Figure 1 shows a bird view SEM image of a junction structure of Si-Gap Plasmonic waveguides. On the Left and the right sides, there are the input and the output ports and, a Gap plasmonic waveguide at the center is connected with Si wire waveguides. Si wire waveguides are covered with Ag evaporated thin film. The thickness and the width of the PMMA fin as the core are 1200 nm and 200 nm, respectively. From optical measurements for samples with various lengths of the plasmonic waveguides using a laser with the vacuum wavelength of 1300 nm, we evaluated the propagation length of the Gap plasmon and the coupling coefficient between Si and ូ plasmonic waveguides to be 10m and 56 %, respectively. And we also found that these values agree with those obtained by 3D ូ FDTD numerical simulation. For the Trench plasmonic waveguide, ូ we have also successfully fabricated various hybrid structure of which characteristics agree with those by numerical simulations. ូ These results shows us that our fabrication process are suitable to ូ fabricate the hybrid photonic circuit. 3ូ
[1] S. I. Bozhevolnyi, (Ed: S. I. Bozhevolnyi ), Plasmonic Nanoguides and Circuits, Chapter 1. (Pan Stanford Fig. 1 SEM images of the juction structure between Si wire and Gap plasmonic waveguides Publishing Pte. Ltd., Singapore, 2009) [2] P. D. Flammer, J. M. Banks, T. E. Furtak, C. G. Durfee, R. E. Hollingsworth and R. T. Collins, Optics Express, 18, 21013-21023 (2010) [3] A. Emboras, R. M. Briggs, A. Najar, S. Nambiar, C. Delacour, Ph. Grosse, E. Augendre, J. M. Fedeli, B. de Salvo, H. A. Atwater and R. Espiau de Lamaestrecs, Applied Physics Letters, 101, 251117 (2012)
199 IN-41
In-plane Holography for Indefinite Plasmonic Beam Engineering
Tao Li*, Ji Chen, Lin Li, and S. N. Zhu College of Engineering and Applied Sciences, Nanjing University, Nanjing 210093, China E-mail address: [email protected]
Abstract: In this talk, I will briefly review the beam engineering for well defined plasmonic waves by different approaches, where a newly proposed hologram will be particularly paid attention. Afterwards, I'd like to show our recent progresses of a totally in-plane realization of an oscillating beam on a free metal surface, which is a quite indefinite beam counter- intuitively against people's recognition.
Controlling the light propagation at will is what the people are always in pursuit of. In recent year, light beam has been discovered in novel forms with nondiffracting properties rather than the common Gaussian beam (e.g., Bessel beam, Airy beam, Mathieu and Webber beams, etc.). Moreover, these novel beams have even been realized in the surface plasmon polaritons (SPP), which enables people to manipulate the light at sub-wavelength scale in unconventional ways [1-3]. Among these progresses, the phase design was a key point, and the amplitude modulation was also considered more recently [4], which are indeed consistent with the principle of optical holography. Nowadays, optical holograms are undergoing a rapid development in three-dimensional (3D) imaging and colorful displays using plasmonic metasurfaces, owing to the artificial elements provide flexible pixel designs. In addition to these spatial holograms where the target and reference beams are both free space light, the near-field SPP wave has already been set as the reference beam, the target, or even both in the recent progresses. Therefore, near-field hologram has stepped into a more popular view with powerful ability in near field routing and beam engineering. Although those impressive SPP beams have been demonstrated, their 2D holograms were usually encoded from a mathematically derived phase that belongs to definite solutions of wave equations or trajectory functions. In this work, we intensively analyzed the holographic beam engineering in an in-plane plasmonic scheme, and found the critical role of the phase correlation with respect to a propagating beam as the object. As an impressive demonstration, an indefinite plasmonic beam that propagates in a sine-function oscillation is realized, which is absolutely against any solution of the free beams [5] (see Fig. 1). By carefully investigation, it is concluded that the amplitude modulation of the source is important in the formation of high quality oscillating beam, which was usually ignored in conventional holograms and caustic beam designs. Our research deepens the understanding of plasmonic beam formation in a holographic perspective, and would enrich people more possibilities in handling the optical field in holographic display, optical trapping, etc.
Fig. 1. Experimental result of the plasmonic oscillating beams realized by in-plane holographic process.
References [1] L. Li, T. Li, S. M. Wang, C. Zhang, and S. N. Zhu, Phys. Rev. Lett. 107, 126804 (2011). [2] L. Li, T. Li, S. M. Wang, and S. N. Zhu, Phys. Rev. Lett. 110, 046807 (2013). [3] A Libster-Hershko, I. Epstein, and A. Arie, Phys. Rev. Lett. 113, 123902 (2014). [4] I. Epstein, Y. Lilach, and A. Aire, J. Opt. Soc. Am. B 31, 1642 (2014). [5] J. Chen, L. Li, T. Li, and S. N. Zhu (submitted).
200 Oral-42
Flexible Coherent Control of Plasmonic Spin-Hall Effect
Shiyi Xiao1, Fan Zhong2, Hui Liu2,*, Shining Zhu2, and Jensen Li1 1National Laboratory of solid State Microstructures & Department and Physics, National Center of Microstructures and Quantum Manipulation, Nanjing University 210093, China 2School of Physics and Astronomy, University of Birmingham, Birmingham, United Kingdom, B15 2TT E-mail address: [email protected]
Abstract: We demonstrate coherent and independent control of SPP orbitals for the two opposite spins using multiple rings of nano-slots with properly designed orientations on a metasurface. This scheme provides us to achieve arbitrary optical spin-Hall effect. This is a form of spin-enabled coherent control and provides a unique way in achieving tunable orbital motions in plasmonics.
Many attentions have been paid to the spin-orbit interaction (SOI) of light using geometric-phase enabled optical and plasmonic systems. Together with the recent developments of resonator-based and geometric- phase-enabled metasurfaces [1-3], it offers an alternative route to excite SPPs through SOI with opposite geometric phases for the two spins. The associated spin-dependent phenomena can be regarded as the optical spin-Hall effect (OSHE) in a more general context about spin-splitting of orbitals. Here we demonstrate coherent and independent control of SPP orbitals for the two opposite spins using multiple rings of nano-slots with properly designed orientations on a metasurface [4]. Figure 1 shows our metasurface platform. It consists of two silver films separated by a dielectric spacer. An array of nano-slots on the upper film is etched with specific orientation profile (x,y) (inset of Fig. 1a). A semiconductor laser at 1064 nm is normally shined on the metasurface to generate a target SPP profile on the air-metal interface. The simulated and experimental SPP profiles for LCP/RCP incidence are shown in Fig. 2 (c-f) which faithfully realize the local SPP profiles within the target region, and indicate the two orbitals (LCP and RCP incidence) can be arbitrarily designed and are not necessarily bounded to beam displacement splitting comparable to a wavelength in real space or bounded to opposite k-space splitting relation between the two spins [18,32-33,42]. Apart from the simple focusing, our current scheme can actually be used to construct far more complicated SPP profiles. In figure 2 (g), we generate a triangle for LCP incidence and a cross-shape for RCP incidence. Fig. 2 (i-l) present the simulated and experimentally achieved SPP profiles, and both clearly show the targeted triangle and cross SPP profile with LCP and RCP incidence.
Figure 1 Arbitrary optical spin-Hall Figure 2 Arbitrary spin-Hall effect. (a) Arbitrary spin- effect of SPP. (a-b), Identical nano-slots splitting: LCP orbital to focus to two spots (red) while RCP with orientation profile (x,y) on the x- orbital to focus a single spot (blue). (b) Top-view SEM y plane. (c) Top-view SEM image of image of the fabricated sample. (c-f) are simulated and experiment sample. (d) Schematics of experimental intensity profiles for LCP and RCP incidence. the experimental set-up. (g) Arbitrary spin-dependent SPP profiles with more complicated pattern: shining LCP generating a triangle pattern (red) and shining RCP generating a cross pattern (blue). h, Top-view SEM image of the fabricated sample. (i- l) simulated and experimental intensity profiles for LCP and RCP incidence.
[1] N. Shitrit, I. Yulevich, E. Maguid, D. Ozeri, D.Veksler,V. Kleiner,and E. Hasman, Science 340, 724 (2013) [2] J. Lin, J.B. Mueller, Q. Wang, G. Yuan,N. Antoniou, X. C. Yuan, and F. Capasso, Science 340, 331 (2013) [3] X.Yin, Z. Ye,J. Rho, Y. Wang, and X. Zhang, Science 339, 1405 (2013) [4] S.Y. Xiao, F. Zhong, H. Liu, S. N. Zhu, and J. Li, Nature Communications 6:8360 (2015)
201 Oral-45
Determination of Zak phase by reflection phase in 1D photonic crystals
WEN SHENG GAO, 1 MENG XIAO, 2 C. T. CHAN, 1,2 WING YIM TAM1,* 1 Department of Physics and William Mong Institute of Nano Science and Technology, Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong, China 2 Department of Physics and Institute for Advanced Study, Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong, China " # _ } % \ _ £ % \ % Vol 40 `` `| `_
202 Session: FRI-IC-S3
Date: March 25 (Friday) Time: 13:30-15:10 Session Chair: . @@ = 0 . = R . ` . 0 7 ? 1 Room: FRI-IC-S3 Oral-46
Plasmonic Archimedean Spiral Modes on Concentric Metal Ring Gratings F U & U
Abstract: Plasmonic Archimedean spiral modes on the surface of concentric silver (Ag) ring gratings are investigated by FDTD simulations and theoretical analyses. These modes are excited by spiral surface plasmon (SP) modes on silver nanorod coupling onto the ring gratings. The observed spiral patterns are ascribed to propagation of SPs on Ag gratings with constant r- and %-directional velocities.
Recently, spin angular momentum (SAM) and orbital angular momentum (OAM) have been extendedly investigated in many optical regions [1], such as optical communication, metasurface, and etc. However, most of researches ues complicated systems or unique metasurface arrays to generate the phase difference in order to obtain the OAM wave. In addition, using OAM wave to produce the spiral mode is also an important research topic. In this abstract, a simple system that can generate the plasmonic Archimedean spiral is designed and examined. When the spiral surface plasmon (SP) mode that propagates on the nanorod emits from the bottom of the nanorod, it still has the velocity at axial and radial directions [2]. And the radial velocity can be decomposed into two orthogonal directions. When the concentric metal ring gratings are placed behind the nanorod, the wave that leaves the bottom of the Ag nanorod will be coupled into the ring gratings (the simulated structure is shown in Fig. 1(a)). The coupling wave propagating on the ring grating will display an Archimedean spiral pattern (see Fig. 1(b)), which is caused by the conservation of r- and %-directional velocities of the SP mode. Furthermore, the spiral SP mode on nanorod with different topological charges can be acquired by applying different polarized incident beams. Therefore, different spiral SP modes will generate different Archimedean spiral pattern on the Ag ring gratings, such as clockwise single-stranded Archimedean spiral and clockwise triple-stranded Archimedean spiral (see Fig. 2(a) and 2(b)).
Fig. 1 (a) Simulation model. (b) Simulated counter-clockwise single-stranded Archimedean spiral mode using FDTD method. The white line is the predicted trajectory with period of 480nm.
Fig. 2 Simulated Archimedean spiral patterns: (a) clockwise single-stranded pattern by using TM0 and HE-1 component modes (topological charge is 1) and (b) clockwise triple-stranded pattern by using HE1 and HE2 component modes (topological charge is -3).
References [1] M. Padgett, J. Courtial, L. Allen, ”Light’s Orbital Angular Momentum”, Phys. Today 57, 35 (2004) [2] S. Zhang, H. Wei, K. Bao, U. Håkanson, N.J. Halas, P. Nordlander and H.X. Xu, “Chiral Surface Plasmon Polaritons on Metallic Nanowires”, Phys. Rev. Lett. 107, 096801 (2011)
204 Oral-49
Freezing photothermal convection in plasmonic optical lattice
Yi-Chong Chen1 and Ya-Tang Yang1 U C C U "
Abstract: Photothermal convection has been adversely disrupt the particle trapping in plasmonic optical tweezer Here we demonstrate a strategy to suppress the plasmonic photothermal convection by using near zero thermal expansion coefficient of water at low temperature. A simple square nanopalsmoic array is illuminated with a loosely Gaussian beam. to produce optical potential for trapping. We observe single particle transport and stable particle assembly due to near-field optical gradient forces at elevated optical power at low temperature. We expect this technique will greatly enhance the trapping capability of plasmonic optical tweezer.
1. Introduction To overcome the diffraction limits of conventional optical tweezer, researchers have developed plasmonic optical trapping techniques using metallic plasmonic nanostructures[1,2]. Previously, our group has reported transport behavior of nano particles in a two dimensional plasmonics enhanced optical lattice[3]. The plasmonic optical trapping is adversely affected by the photothermal convection due to the heating of metallic plasmonic structures. Efforts have been made to understand and suppress such phothermal heating effects. 2 R the usage of copper substrate for enhanced heat sinking between the plasmonic nanostructure and substrate and therefore allow higher optical power to be used for trapping.[4] ` R } antenna.[5] Our group has also characterized the photothermal convection for a simple square plasmnic optical lattice.[6] The buoyancy force that drives the natural convection can be estimated by fb= gT, where g is the gravitational acceleration, the thermal expansion coefficient of medium, and Tthe temperature increase,using the Boussinesq approximation. [7] Here we report suppression of photothermal convection by using a unique property of water, i.e., near zero thermal expansion coefficient at ~ 4°C.
2. Experimental setup We build an inverted optical microscope setup modified from a commercial optical trapping kit. An infared diode laser of 980 nm is used to excite the plasmonic optical lattice. The trapping action of nanoparticle under such potential is recorded by a CCD camera with fluorescent imaging. The optical lattice is created by illuminating an array of gold nanodisks with a loosely focused Gaussian beam. The trapping action of nanoparticle under such potential is recorded by a CCD camera with fluorescent imaging. We have custom made a sample stage with thermoelectric cooling capability.
3. Results and discussion We observe marked difference in particle trapping behavior between room temperature and ~4°C. Figure 2 displays the representative result of single particle transport within the optical lattice at ~4°C. At the sample optical power at room temperature, however, the particles will get expelled, and disappear once they enter into the optical lattice. The temperature profile can be calculated using the analytic formula for an array of R [7-9].
4. Conclusion We have reported a strategy to suppress the photothermal convection for optimal trapping of micro and nano particles in the plasmonic optical lattice. We expect this technique is applicable to a wide range of samples including biological samples. It can also be combined with other engineering strategy such high thermal conductivity substrate to further enhance the trapping capability of plasmonic optical tweezer.
ġ ġ??\ ^ V X \ # + !
^ % ' *
+ ! / : ; # <>? [>\ [ / ] _
Fig. 1. (Left) Experimental setup. (Right) Representative single particle trajectory entering the optical lattice at ~4°C.
[1] D. A. Grier , 424, 810-816 (2003). [2] M. L. Juan, R. Gordon, Y. Pang, F. Eftekhari, and R. Quidant , 5, 349-356 (2011). [3] Y. Chen, C. C. Hung, A. T. Lee, J. S. Huang, and Y. T. Yang, ., 13, 4118-4122, (2013). [4] K. Wang, E. Schonbrun, P. Steinvurzel and K. B. Crozier Nat. Commun., 2, DOI:10.10138, (2011). [5] B. J. Roxworthy, A. M. Bhuiya, S. P. Vanka and K. C. Jr. Toussant, Nat. Commun 5, DOI:10.1038, (2013). [6] T. P. Yang, G. Yossifon, and Y. T. Yang, (submitted). [7] J. S. Donner, G. Baffou, D. McCloskey and R. Quidant, ACS Nano, 5, 5457-5462 (2011). [8] G. Baffou, et al., ACS Nano, 8, 6478-6488, (2013).
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Angled Nanospherical-Lens Lithography as a high-throughput method to fabricate periodic arrays of various nanostructures
Yi-Hsin ChienƇ, Chang-Han WangƇ, Chi-Ching LiuƇ, and Yun-Chorng ChangƇ*, Ƈ Research Center for Applied Science, Academia Sinica, Taipei, Taiwan. E-mail address: [email protected]
Abstract: } µ1 1 11 11 ¥± } µ ` ´ µ µ } } }
206 Oral-55
Interface States of Binary Hyperbolic Metamaterials
Ieng Wai Un1 and Ta Jen Yen2,* U C C U S ( $
Abstract: We systematically investigate the interface admittance of hyperbolic metamaterial (HMM) and theoretically demonstrate the existence of interface states between three types of interface: dielectric/HMM, metal/HMM and HMM/HMM.
Introduction Recently, hyperbolic metamaterials [1] have attracted significant research interest. They process hyperbolic iso-frequency surface, which attributed to their indefinite electric permittivity ( ). The hyperboloid iso-frequency surface promises that the HMM can support larger Fourier momentum component than that in vacuum, which leads to negative refraction [2], subwavlength image resolution[3], diverge photonic density of states and enhanced Percell factor [4]. In particularly, the subwavelength image resolution has been demonstrated by cylindrical metal/dielectric multilayer so called hyperlens [3]. The enhanced Purcell effect has also been demonstrated by the enhancement of spontaneous emission rate due to the divergence of photonic density of states [4].
Interface states of HMM Typically, the permittivity tensor of HMM is determined by the effective medium approach [1] if the size of the composite unit of metamaterial is much smaller than the wavelength, i.e., long wavelength limit. As an example, for HMM composed of metal/dielectric multilayer, the principle components of permittivity tensor TĠ ĠͮTė ė TĠTėʚ Ġͮ ėʛ are given by 3 Ɣ 4 Ɣ and 5 Ɣ , where (ʚ ʛ is the permittivity of metal Ġͮ ė TĠ ėͮTė Ġ (dielectric), ͕(ʚ͕ ʛ is the thickness of metal (dielectric) layer. Instead of using the effective medium approach, we adopt the full Maxwell equations calculation by Bloch theory to investigate the plasmonic band structure of binary HMM and demonstrate the existence of interface states between three types of interface: dielectric/HMM, metal/HMM and HMM/HMM, opening up a new degree of freedom in controlling the optical properties in the plasmonic band gap region.
Fig. 1 (a) Schematic diagram of binary HMM. (b) Plasmonic band diagram of binary HMM with ͕( Ƙ͕ and (c) ͕( Ɨ͕ . The gap regions are covered by red and blue colors if the HMM form interface state with dielectric and metal, respectively. The circles show the dispersions of the interface states.
The plasmonic band structure of binary HMM is shown in Fig. 1(b) and Fig. 1(c) for the case of ͕( Ƙ ͕ and ͕( Ɨ͕ , respectively. For the case of ͕( Ƙ͕ , only dielectric material can form interface state with the HMM. However, for the case of ͕( Ɨ͕ , we show that the band crossing occurs when the in plane TĠQėϙ momentum ͟ and frequency ! satisfy ( ƍ ƔR and (͕( Ɣ ͕ , where (Q ȸ and ͦ ͦ ͦ QĠQė (Q Ɣ͟ Ǝ (Q ! . In the plasmonic band gap region, we show that the HMM can form interface state with dielectric materials if ͟ Ɨ͟ ; but form interface state with dielectric materials if ͟ Ƙ͟ . We denote the HMM forming interface state with dielectric (metallic) material as metallic-like (dielectric-like). We also show the interface state formation on the interface between metallic-like and dielectric-like HMM.
References [1] A. Poddubny, I. Iorsh, P. Belov, and Y. Kivshar, Nat Photon 7, 948 (2013). [2] D. R. Smith, P. Kolinko, and D. Schurig, J. Opt. Soc. Am. B 21, 1032 (2004). [3] Z. Liu, H. Lee, Y. Xiong, C. Sun, and X. Zhang, Science 315, 1686 (2007). [4] Z. Jacob, I. I. Smolyaninov, and E. E. Narimanov, Applied Physics Letters 100, 181105 (2012).
207 Oral-58
Performance comparison of air and immersion Linnik objectives in coherence scanning interferometry H Mukhtar, A Leong-Hoï, R Claveau, P Montgomery, F Anstotz S " & "& A The axial resolution in Coherence Scanning Interferometry (CSI) for the roughness measurement of surfaces [1] typically depends on both the coherence of the illumination light used and the aperture of observation while the lateral resolution depends on the wavelength and the numerical aperture (NA) [2]. The performance also depends on the algorithm, optical components and the samples themselves. In theory, a high-NA Linnik setup with immersion objectives, offers the highest spatial resolution compared with Michelson and Mirau interference objectives. However, in practice, noise and limited resolution in the acquired images affects the detection and observation sensitivity of the system and has thus to be taken into account. The noise can be much reduced with image processing techniques. In this work, we compare the performance of air and immersion objectives in two modified commercial microscopes (from FOGALE nanotech and Leitz). Each microscope uses different light sources and piezo displacement systems, but the same camera and software. Measurements are made on different types of 2D and 3D test samples, including calibrated fine gratings and glass beads as well as square steps. The lateral and axial resolutions are determined by analyzing carefully selected line profiles of the samples. In addition, a series of post processing techniques involving averaging, dark frame, and flat field correction are performed to achieve an improved lateral resolution of the acquired images in order to approach the theoretical optical resolution limit of the systems. Since these techniques have already been used on air objectives and have given some encouraging results in improving the lateral resolution of the system [3], in the same way, they are also used to improve the results with immersion objectives.
Keywords: microscopy, low coherence interferometry, immersion Linnik objective, improvement of axial resolution and lateral resolution
[1] J. Schmit, J. Reed, E. Novak, and J.K. Gimzewski, “Performance advances in interferometric optical profilers for imaging and testing,” J. Opt. A: Pure Appl. Opt., 10, 064001, 1-7, 2008. [2] P. Montgomery, D. Montaner, F. Anstotz, B. Serio. Wide field nanometric materials analysis by diffraction limited far field optical nanoscopy, Journal of Physics: Conference Series, Institute of Physics: Open Access Journals (SNIP : 0.188, SJR : 0.191), Vol. 98(012001), 2012 [3] A. Leong-Hoi, R. Claveau, M. Flury, W. Uhring, B. Serio, P.C. Montgomery, “Detection of defects in a transparent polymer with high resolution tomography using white light scanning interferometry and noise reduction”, Proc. SPIE, Vol 9528, 952807, 2015.
208 Session: FRI-RI-S3
Date: March 25 (Friday) Time: 13:30-15:10 Session Chair: = . 0 7 ? . 7 78 ? . ` . ? 0 7 ? 1 Room: 1st Conference Room (3F) FRI-RI-S3 Oral-47
Surface Plasmon Polaritons Amplitude Modulations by using Zeeman effect and Polarization control
Chang, Cheng-Wei1 and Yen, Ta-Jen1,* U C F A S C " " U
Abstract: We report the miniaturized surface plasmon polaritons amplitude modulation (SPPAM) by using Zeeman effect and polarization control. SPPAM devices were integrated by the modulated light sources and polarization sensitive Fishbone (FB) nanocouplers. The modulated signals can be carried on the angular-frequency difference and the frequency of various polarization states for 1.66 MHz and 0.5-10k Hz under the 632.8 nm laser excitation. Such the SPPAM opens up new modulation methods and can be explored to the nanophotonic applications.
1. Introduction to main text format and page layout Plasmonic modulation has been taken great efforts for the miniaturization to the compact devices, which is usually comprised of the baseband, wave-carrier, and readout system. To date, the size miniaturization can be proposed to the subwavelength structures that can reduce the long transmission phase delay and provide the compact device like plasmonic phase modulators [1], and gap plasmon phase modulators (GPPM) [2]. Using the subwavelength structures to couple the SPP from the free space, nanoslits [3] and nanogratings [4] are the most commonly employed. Interestingly, unidirectional SPP couplers have been widely paid attention to its SPP wave directional control, such as an aperiodic groove [5], a dipole mode rotator [6], and a Fishbone (FB) structure [7]. FB couplers take the advantages of normal incidence and two SPP wave channels by polarization states that are suitable for the practical use and sensitive to the polarization states [7]. Herein, we use FB couplers with Zeeman laser and polarization generator to couple the modulated SPP at the air/Ag interface. Using the commercial Zeeman laser and the integrated polarization generator, we can effectively demonstrate the angular-frequency difference at 1.66 MHz and the period speed of various polarization states along the Poincaré sphere at 0.5-10k Hz. We expect that SPPAM can be further employed for the nanosensors and other practical plasmonic applications. Figure 1 shows the SPPAM measurement for the Zeeman effect and the various polarization states. We use 4ǘ4 FB nanoarrays, waveplates, and polarizer to control the polarization states. The modulated signals were given for 1.66 MHz and 0.5-10k Hz in Figure 1 (a) and 1(b)-(f), respectively. The results show that the SPPAM is demonstrated by photomultiplier tube (PMT). In conclusion, we have demonstrated the SPPAM for Zeeman effect at 1.66 MHz and for various polarization states at 0.5-10k Hz. This modulation method are proposed for reducing the signals transmission channels by the subwavelength nanostructures and can be configured for the on-chip devices to the future applications
2. Figures and tables
Fig. 1. Measurement of the SPPAM for Zeeman effect and the various polarization states.
3. References [1] Melikyan, A. et al. High-speed plasmonic phase modulators. Nature Photon. 8, 229M233 (2014). [2] Dennis, B. S. et al. Compact nanomechanical plasmonic phase modulators. Nature Photon. 9, 267M273 (2015). [3] Wu, Y. et al. Intrinsic optical properties and enhanced plasmonic response of epitaxial silver. Adv. Mater. 26, 6106M6110 (2014). [4] Wang, C. et al. Giant colloidal silver crystals for low-loss linear and nonlinear plasmonics. Nature Commu. 6, 7734M7740 (2015). [5] Huang, X. et al. Compact aperiodic metallic groove arrays for unidirectional launching of surface plasmons. Nano Lett. 13, 5420M5424 (2013). [6] Lin, J. et al. Polarization-controlled tunable directional coupling of surface plasmon polaritons. Science 340, 331M334 (2013). [7] Chen, C. et al. Enhanced vibrational spectroscopy, intracellular refractive indexing for label-free biosensing and bioimaging by multi-band plasmonic-antenna array. Biosens. Bioelectron. 60, 343M350 (2014).
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Phonon Stimulated Scattering and Single Molecule Dynamics in Reproducible Ultrasensitive SERS Hotspots
Tian Yang, Jing Long, Hui Yi, Hongquan Li State Key Laboratory of Advanced Optical Communication Systems and Networks, Key Laboratory for Thin Film and Microfabrication of the Ministry of Education, UM - SJTU Joint Institute, Shanghai Jiao Tong University, Shanghai 200240, China. E-mail address: [email protected]
Abstract: With an experiment method that produces reproducible and ultrahigh enhanced Raman scattering in single deterministic plasmonic hotspots, we have discovered a heterogeneous phonon pumping effect and observed single molecule chemical events.
Using enhanced Raman scattering in single deterministic plasmonic hotspots to probe single molecule structures, dynamics and chemistry is a holy grail for the study on plasmon-enhanced Raman scattering [1-3]. The development in this direction has been hindered by the challenge to achieve both reproducible and ultrahigh enhancement of Raman scattering simultaneously [4-5]. In addition, plasmon-enhanced Raman scattering is still an incompletely understood subject, which is involved with complicated quantum physical and chemical effects. By illuminating a 60 nm gold nanosphere M atomically flat gold plane antenna with focusing a radially polarized He-Ne laser beam, as in Fig. 1(a), we have achieved a 109-10 electromagnetic enhancement factor of surface enhanced Raman scattering (SERS) for a monolayer of small molecules, with an unprecedented root- mean-square error (RMS) down to 100.08 in individual hotspots (not shown) [6]. Further, a heterogeneous nonlinear relation between SERS intensity and laser power is experimentally observed with malachite green isothiocyanate (MGITC) molecules, as in Fig. 1(b), and theoretically explained by quantum phonon pumping [7]. This is a piece of evidence for the recently proposed molecular cavity optomechanics theory and shows more complicated behaviors rooted in the quantum nature of molecular vibration [8]. We have also been able to observe changes in the Raman spectra in real time, which tell chemical events on the single molecule level, including plasmon-driven dimerization of 4-nitrobenzenethiol (4NBT) to dimercaptoazobenzene (DMAB), DMAB desorption, and its trans-cis conformation switching as in Fig. 1(c). Isomer switching is an interesting topic for molecular device research.
(a) (b) (c) Fig. 1. (a) Schematic of the experiment. (b) SERS intensity at 1370 cm-1 versus laser power, for an antenna coated with a monolayer of MGITC molecules. (c) Time-resolved SERS spectra showing DMAB trans-cis conformation switching. Red: cis; green: trans.
In summary, our experiment has enabled reproducible and ultrahigh SERS enhancement in deterministic plasmonic hotspots. We have used it as an efficient tool to explore SERS phenomena in single nanometer scale hotspots, including the discovery of a heterogeneous phonon pumping effect and the observation of single molecule chemical events.
[1] E.C. Le Ru, and G. Etchegoin, Annu. Rev. Phys. Chem. 63, 65-87 (2012). [2] R. Zhang, Y. Zhang, Z. Dong, S. Jiang, C. Zhang, L. Chen, et al. Nature 498, 82-86 (2013). [3] J.O. Arroyo, and P. Kukura. Nature Photon. 10, 11-17 (2016). [4] Y. Fang, N.-H. Seong, and D.D. Dlott, Science 321, 388-392 (2008). [5] D. Wang D, W. Zhu, M.D. Best, J.P. Camden, and K.B. Crozier, Nano. Lett. 13, 2194-2198 (2013). [6] J. Long, H. Yi, H. Li, and T. Yang, arXiv:1512.03507 [physics.optics] (2015). [7] T. Yang, and J. Long, arXiv:1601.03324 [cond-mat.mes-hall] (2016). [8] P. Roelli, C. Galland, N. Piro, and T.J. Kippenberg, Nature Nanotech., advance publication (2015).
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Non-lithographic Nanopatterning for SERS Au- nanoarray
Agnes Purwidyantria, Chao-Sung Laib,c,* aBiomedical Engineering, Chang Gung University, Taoyuan, Taiwan bDepartment of Electronic Engineering, Chang Gung University, Taoyuan, Taiwan E-mail address: [email protected] , [email protected]
Abstract: In this research, SERS substrates were prepared by producing Au-nanoarray grown on polystyrene (PS) nanospheres-coated ITO. Al2O3 and Cr adhesion layers were applied to support the growth 3 nm and 10 nm Au generated by thermal evaporation. Findings showed that Al2O3 as adhesion layer yielded higher particles density than the typical Cr layer especially in the application of small particles (3 nm) that consequently exhibit higher SERS signals. Keywords: Au-nanoarray, polystyrene, SERS, Al2O3, adhesion layer, non-lithographic
1. Introduction There are numerous techniques to develop SERS substrates with unique morphological characteristics that result in distinct SERS response [2,3]. However, typical technique by lithography process tends to be laborious, and hard to be extended to large dimensions. Here, we report on a convenient nanotechnique to fabricate Au-nanoarray templated by rough PS-coated ITO substrates combined with Al2O3 adhesion layer [3] to improve plasmonic behavior of our substrates and compared it with typical Cr adhesion layer.
2. Materials and Methods A 100 nm PS nanospheres was drop-casted onto the surface of the ITO. Two nm of Al2O3 and/or Cr adhesion layer was deposited to support thermally evaporated 3 nm and/or 10 nm thick of Au. Field electron scanning electron microscope (FE-SEM) was used to capture the surface, while SERS signal was obtained from the detection of 1 3M rhodamine (R6G) molecules. 3. Results and Discussion The fact that Au nanoparticles (3 nm thick) on Al2O3 which is optically transparent, chemically stable, resistant to strong acid and alkaline attack and strong in ionic interatomic bonding [3] achieved the highest particles density as compared to others (Fig 1 and Table 1) implies that this adhesion layer is beneficial for nanopatterning. SERS response shown in Fig 2 explains that the combination of PS and Al2O3 adhesion layer was favorable to enhance plasmonic behavior of the substrate with approximately 5-7 times larger response.
Fig 1. Surface morphology by different Fig 2. R6G SERS response by different combination of combination of nanopatterns nanopatterns
Table 1. Particle size and interparticle distance obtained from different combination of nanopatterns
Composition Particle Size (nm) Interparticle Distance (nm) ITO+PS+Al2O3+3nm Au 11-12 5-6 ITO+PS+Cr+3nm Au 12-15 17-20
ITO+PS+Al2O3+10nm Au 33-38 25-27 ITO+PS+Cr+10nm Au 27-45 20-25
4. Conclusion A novel non-lithographic nanopatterning technique was implemented by applying Al2O3 as adhesion layer for Au nanoarray growth on PS-roughened substrate. High density of smaller particles was found to yield well-controlled interstitial distance that immensely augment LSPR effect on SERS detection.
5. References [1] Z. Huang, G. Meng, Q. Huang, Y. Yang, C. Zhu, and C. Tang, Adv. Mater., vol. 22, no. 37, pp. 4136M 4139, 2010. [2] D. Choi, Y. Choi, S. Hong, T. Kang, and L. P. Lee, Small, vol. 6, no. 16, pp. 1741M1744, 2010. [3] V. Guarnieri, L. Biazi, R. Marchiori, and A. Lago, Biomatter, vol. 4, no. 1, p. e28822, 2014.
212 Oral-56
! "#$% & # #
Xun Lu and Ya Yan Lu C F
Abstract: ` R } ded by concentric rings of grooves) are useful for realizing practical applications of the extraordinary optical transmission phenomenon. Existing optimal designs are limited to R } transmission is possible when the number of grooves is increased.
1. Introduction The extraordinary optical transmission (EOT) phenomenon appears in metallic films with a periodic array of subwavelength holes, or a single hole surrounded by concentric r } Rs eye structures). The physical mechanisms for EOT have been extensively studied. Using rigorous numerical methods such as FDTD, a } R of grooves [1,2]. It is also observed that transmission may not increase as the number of grooves is increased. In [3], we developed a highly efficient semi- R R th many grooves, and found that in some cases, transmission appears to increase monotonically with the number of grooves, and very high transmission is possible.
2. Methods In [3], we presented the so-called vertical mode expansion method (VMEM) for analyzing structures with continuous rotation symmetry. The method expands the field in each annular region in one-dimensional vertical modes (that depend on z) and two-dimensional cylindrical waves (that depend on the horizontal variables), where z gives the vertical direction perpendicular to the metallic film. The method takes full advantage of the rotation symmetry, and solves only a single Fourier mode (in angle variable) for normal incident waves. Since the method is very efficient, we can easily analyze b R grooves.
3. Results As in [2], we consider a R gold film with thickness 280nm, a hole with radius 200nm, and grooves with width 300nm and depth 90nm. The inner radius of the first groove is 540nm, and the grooves are placed periodically in radius r with period P. The problem is considered for normal incident plane waves with wavelength 800nm. The refractive index of gold is assumed to be 0.1808+5.117i. For P=780nm, the normalized transmission (total transmitted power divided by the power of the incident wave impinging on the hole) reaches a maximum of 52.56 for N=22 grooves. However, we found that if P=795nm, the normalized transmission increases as the number of grooves N is increased (at least up to N=100), and the normalized transmission is 566 for N=100. ` } R structure has many grooves.
[1] O. Mahboub, S. C. Palacios, C. Genet, F. J. Garcia-Vidal, S. G. Rodrigo, L. Martin-Moreno, and T. W. Ebbesen, Optics Express, 18, 11292-11299 (2010). [2] A.Yamada and M.Terakawa, Optics Express 21, 21273M21284 (2013). [3] X. Lu and Y. Y. Lu, Journal of the Optical Society of America B, 32, 2294-2298 (2015).
213 Oral-59
Broadband negative refraction in a two-dimensional photonic crystal without any negative index material
Ummer K.V1 and R.Vijaya1,2 1Department of Physics, Indian Institute of Technology Kanpur, Kanpur 208016, INDIA 2Centre for Lasers and Photonics, Indian Institute of Technology Kanpur, Kanpur 208016, INDIA ,
Abstract: Negative refraction is demonstrated in TM polarization from a honey-comb lattice of air holes on a silicon slab, without resorting to metamaterials. As a result, a super lens with a reso ( with a periodic dielectric structure.
1. Introduction The dispersion characteristics of photonic crystals (PhC) can result in negative refraction even without any constituent material possessing a negative index of refraction [1]. The research on negative refraction can thus move from materials to the fabrication platform. All the applications base ± R amaterials [2] can be replaced with lossless periodic dielectric structures by suitably engineering the structure to have the desired negative refraction characteristics. Broadband all-angle negative refraction can lead to high resolution sub-wavelength imaging in photonic crystal devices if the effect is possible in the lowest band of frequencies. In this work, we demonstrate negative refraction effects in a honey-comb PhC consisting of air holes in Si ( = 12, r/a = 0.44) for TM polarization (electric field parallel to hole axis), for both TM2 and TM3 bands at values of ²( in the range of 0.17 to 0.204 with a broadband width of 17% within an angular range of 45 c
2. Description of Results The band structure and equi-frequency contours of the honey-comb lattice are calculated with BandSOLVE module of RSoftTM by using plane wave expansion method while the beam propagation characteristics are analyzed with FullWAVE module of RSoftTM using FDTD method. A schematic of the honey-comb lattice primitive unit cell is in Fig. 1(a). The first four bands for TM polarization are shown in Fig. 1 (b) while the effective index for the 2nd and 3rd bands is shown in Fig. 1(c). The angular dispersion characteristics for the 2nd b ²( ³ } The PhC interface is shown as c ` ´ - ´ ²( ³ 2 black curve and for homogeneous external medium (air) is the blue circle. The blue dashed arrow is the incident wave vector at 45 from the normal of the PhC interface and the dotted black line is the constructed line that conserves the incoming wave vector component parallel to the PhC interface. One can see that the outgoing k vector (dashed magenta arrow) and group velocity (the refracted light energy, green arrow in Fig. 1 (d)) are in opposite directions and the refracted light bends towards the same side of the normal as the incident wave, resulting in negative refraction. For beam propagation studied (at a/( ³ using FDTD, the image is formed at 3.29 3m for an object distance of 1 3m. All-angle negative refraction is possible for ²( in the range of 0.199 to 0.203. The calculated FWHM (Fig.1(e)) is ££ ) ´ } ?( one can get a clear image of two point objects with ( is better than the reports in [3-4].
Fig. 1 (a) Honey-comb lattice with primitive unit cell. (b) First four bands for TM polarization. (c) Effective index of 2nd and 3rd bands calculated from BandSOLVE module of RSoftTM. The shaded region shows the frequency range where the PhC shows left-handed behavior. (d) Angular dispersion for the PhC oriented c ht at ²( = 0.18. Blue arrow is the incident wave vector at 45 from normal of the PhC interface. Black curve is the PhC contour and blue circle is of air at ²( = 0.18. The outgoing wave vector is shown as dashed magenta arrow and green arrow is the group velocity. (e) Far field intensity at image point with FWHM of 0.196(
Acknowledgements: The work was partially supported by IRDE, Dehradun, India under the DRDO Nanophotonics program (ST-12/IRD-124) and by DST, India under the India-Taiwan S&T co-operation project (GITA/DST/TWN/P-61/2014).
References [1] C. Luo, S. G. Johnson, J. D. Joannopoulos, and J. B. Pendry, Phys. Rev. B, 65, 201104(R) (2002). [2] V. G. Veselago, Uspekhi Fiz. Nauk 92, 517-526 (1967). [3] R. Gajic, R. Meisels, F. Kuchar, K. Hingerl, Opt. Express, 13, 8596-8605 (2005). [4] X. Wang, Z. F. Ren and K. Kempa, Opt. Express, 12, 2919-2924 (2004).
214 FRI-R2-S3
Session: FRI-R2-S3
Date: March 25 (Friday) Time: 13:30-15:10 Session Chair: R @ 0 7 .R] . % % ? 1 Room: 2nd Conference Room (3F) Oral-48
Novel Design of Plasmonic Doppler Grating for Color Sorting and Index Sensing
Fan-Cheng Lin (݅ጄ၈), Kel-Meng See (৪ഩܴ), Jer-Shing Huang (ণᏌ) U C C " " U $
Abstract: The stylish design of the two dimensional grating, Plasmonic Doppler Grating (PDG), can be served as continuous azimuthal angle-dependent periodicity for azimuthal angle-resolved plasmonic color sorting and index sensing. PDG consists of a set of non- concentric circular rings that mimics the wavefronts of a moving point source and, therefore, presents azimuthal angle-resolved grating periodicity. For specific applications, the center and span of working frequency window are completely designable. We detail the design, fabrication and optical characterization of the PDG and demonstrate its exemplary applications in color sorting and index sensing. In this letter, we show that broadband source can be sorted continuously into surface plasmons and the variation in surrounding index can be reported as the change of in-plane angle distribution of color. Applications of PDG in grating couplers for silicon photonic circuits, hydrogen sensing, surface plasmon- enhanced spectroscopy and non-linear signal generation are anticipated.
Introduction Grating offers lattice momentum to fulfill the momentum matching formula [1]. This formula links the resonant wavelength to the grating periodicity and provides a simple guideline for the design of grating surface plasmon (SP) couplers. For its simplicity, grating have been widely used for index sensing [2], color filtering [3], surface enhanced spectroscopy [4]. However, most of these grating structures are designed to have one constant periodicity and the performance is optimized at the fixed resonant frequency under certain illumination condition. For multi-band analytical applications, SP couplers with multiple grating periodicities are needed. In this letter, we present a novel design of Plasmonic Doppler grating (PDG) that provides azimuthal angle-dependent periodicity for broadband and continuous plasmonic resonance at optical frequencies. The center and span of the working frequency window of PDG can be freely designed to best fit the desired applications. Because of the azimuthal angle- } }ironmental index by the change of color distribution in azimuthal angle. Here, we detail the theoretical design, experimental fabrication and optical characterization of the PDG and demonstrate two exemplary applications in continuous broadband color sorting and index sensing. The design of PDG may find applications in gas sensing, broadband plasmon-enhanced spectroscopy [4] and non-linear signal generation [5]. The design can also be applied to dielectric materials to fabricate, for example, broadband couplers or frequency routers in silicon photonic circuits or grating for two-dimensional spectroscopic microscopy.
Fig. 2. Optical characterization of PDG.
[1] Ebbesen T. W., Lezec H. J., Ghaemi H. F., Thio T., & A. Wolff P., Extraordinary Optical Transmission through Sub-wavelength Hole Arrays. Nature 391, 667-669 (1998) [2] Lee K. L., et al., Enhancing Surface Plasmon Detection Using Template-Stripped Gold Nanoslit Arrays on Plastic Films. ACS Nano 6, 2931-2939 (2012). [3] Laux E., Genet C., Skauli T., & Ebbesen T. W., Plasmonic Photon Sorters for Spectral and Polarimetric Imaging. Nat. Photon 2(3), 161-164 (2008) [4] Andrade G. F. S., Min Q., Gordon R., & Brolo A. G. Surface-Enhanced Resonance Raman Scattering on Gold Concentric Rings: Polarization Dependence and Intensity Fluctuations. J Phys Chem C 116(4), 2672- 2676 (2012) [5] Wang C. Y., et al. Giant colloidal silver crystals for low-loss linear and nonlinear plasmonics. Nat. Commun 6, 7734 (2015)
216 Oral-51
Transformation-optics macroscopic visible-light beyond two dimensions cloaking
Chia-Wei Chu1,2), Xiaomin Zhai1,2), Chih Jie Lee2,3), Po-Hao Wang1,2), Yubo Duan4), Din Ping Tsai2,3,5), Baile Zhang6,7), andYuan Luo1,2,8) 1)Center for Optoelectronic Medicine, National Taiwan University, Taipei, Taiwan 2)Molecular Imaging Center, Optical Imaging Core Laboratory, National Taiwan University, Taipei, Taiwan 3)Department of Physics, National Taiwan University, Taipei, Taiwan 4)Department of Bioengineering, Faculty of Engineering, National University of Singapore, Singapore 5)Research Center for Applied Science, Academia Sinica, Taipei, Taiwan 6)Division of Physics and Applied Physics, School of Physical and Mathematical Sciences, Nanyang Technological University, Singapore 7)Centre for Disruptive Photonic Technologies, Nanyang Technological University, Singapore 8)Department of Optics and Photonics, National Central University, Taoyuan, Taiwan E-mail: [email protected]
Abstract: Transformation optics, a geometrical design strategy of light manipulation with both ray trajectories and optical phase controlled simultaneously, promises without precedent an invisibility cloaking device that can render a macroscopic object invisible even to a scientific instrument measuring optical phase. Previous macroscopic cloaks only demonstrated the recovery of ray trajectories after passing through the cloaks, while whether the optical phase would reveal their existence still remains unverified. This is the first time that we could have invisibility cloaks hiding large objects from visible light beyond two dimensions. As an extension of previous two-dimensional (2D) macroscopic cloaks, this almost-three-dimensional cloak exhibits three-dimensional (3D) invisibility for illumination near its center (i.e. with a limited field of view), and its ideal wide-angle invisibility performance is preserved in multiple 2D planes intersecting in the 3D space. Optical path length has been verified with a broadband pulsed-laser interferometer, which provides unique experimental evidence on the geometrical nature of transformation optics.
Figure 1: The setup of measurement of phase-preservation using Michaelson interferometer and the heights of with respect to different incident polar and azimuthal angles.
References: [1] Leonhardt, U. Optical conformal mapping. Science 312, 1777M1780 (2006). [2] Valentine, J., Li, J., Zentgraf, T., Bartal, G. & Zhang, X. An optical cloak made of dielectrics. Nature Mater. 8, 568-571 (2009).
217 Oral-54
Photoacoustic Signal of Core-shell Gold Nanorod Colloid
Shang-Yung Yu1, Shiao-Wen Tsai2,3, Yu-Ping Lin3, Yunju Chen1, and Jiunn-Woei Liaw1,2,4* B U B U " B U S S S B B C U
Abstract: The photoacoustic (PA) signal of nanobubbles induced by the irradiance of nanosecond pulsed laser in core-shell gold nanorod (GNR) colloid was measured. Due to the plasmonic heating of GNRs, the cavitation of nanobubbles generates PA signal. Via a focused high-frequency ultrasonic transducer, the PA signal can be measured. Our results show that the wavelength-dependent PA amplitude of coreshell GNR colloid is more stable than that of bare GNR one.
1. Introduction Recently, the photoacoustic (PA) signal induced from the cavitation of nanobubbles in gold nanoparticle (GNP) colloid irradiated by a pulsed laser has been studied [1]. The nanobubbles are formed due to the plasmonic heating of GNPs. Consequently, the cavitation of each nanobubble emits a tiny shock wave, and then the PA signal of the collection of nanobubbles is generated. Moreover, the study of PA signal of gold nanorod (GNR) has also attracted a lot of attention [2]. For GNR, there are transverse surface plasmon resonance (TSPR) and longitudinal surface plasmon resonance (LSPR), where LSPR is tunable according to its aspect ratio (AR). Because of this merit, the LSPR of GNR can be tailored on demand by adjusting AR. An important application of GNR is the contrast agent for enhancing PA imaging. However, the disadvantage of GNR is that its thermal stability is not poor. In particular, the shape of GNR is easily changed if irradiated by a light at the LSPR; the photothermal effect is severe. Therefore we used coreshell GNR instead of bare GNR for PA experiment, where the shell is silica.
2. Method A Nd: YAG laser of second harmonic 532 nm (Surelite-10, Continuum) and an optical parametric oscillator (OPO) were used to generate a pulsed laser beam with different wavelengths (675 nm-1000 nm) [3]. The duration time of each pulse is 5 ns. The pulsed laser beam is focused by an objective (x10) into a cuvette containing the core-shell GNR colloid. A focused ultrasonic transducer with a 25-MHz center frequency, 1/2” focal length was used to measure the PA signals of plasmonic nanobubbles. An ultrasound Pulser/Receiver (DPR300, JSR) was used for the PA signal amplification and filter [4].
3. Result Via the focused high-frequency ultrasonic transducer, the PA signal can be measured in coreshell GNR colloids with different concentrations. We changed the power and wavelength of pulsed laser. The amplitude of PA signal is increased as the pulse energy of Nd: YAG laser increases. Compared to the PA signal of bare GNR colloids, our experimental results show that the wavelength-dependent PA amplitude of coreshell GNR one is more stable; the error bar of PA signal of coreshell GNR is smaller than that of bare GNR.
4. Conclusion We developed an ultrasound measurement system to detect the PA signal of nanobubbles in coreshell GNR colloid, induced by a pulsed laser. Through a focused ultrasonic transducer, we can detector the PA signal. Our results show that the wavelength-dependent PA amplitude of coreshell GNR colloid is more stable than that of bare GNR one. In addition, the amplitude of PA signal is increased as the pulse energy of laser increases.
[1] E. Y. Lukianova-Hleb, and D. O. Lapotko, Appl. Phys. Lett. 101, 264102 (2012). [2] É. Boulais, R. Lachaine, and M. Meunier, J. Phys. Chem. C 117, 9386%9396 (2013). [3] S.-Y. Yu, S.-W. Tsai, Y.-J. Chen, and J.-W. Liaw, Microelectron. Eng. 138, 102-106 (2015). [4] J.-W. Liaw, S.-W. Tsai, H.-H. Lin, T.-C. Yen, and B.-R. Chen, J. Quant. Spectrosc. Radiat. Transfer 113, 2234-2242 (2012).
218 Oral-57
Local optical and structural properties of GaN nanowires with AlxGa1-xN segments
Anna Reszka 1*, Kamil Sobczak 1, Uwe Jahn 2, Ute Zeimer 3, Agnieszka Pieni=bek 1, Marta Sobanska 1, Kamil Klosek 1, Zbigniew R. Zytkiewicz 1, Bogdan J. Kowalski 1 1Institute of Physics, Polish Academy of Sciences, Al. Lotnikow 32/46, 02-668 Warsaw, Poland 2Paul-Drude-Institut für Festkörperelektronik, Hausvogteiplatz 5M7, D-10117 Berlin, Germany 3Ferdinand-Braun-Institut, Leibniz-Institut für Höchstfrequenztechnik, Gustav-Kirchhoff-Str. 4, 12489 Berlin, Germany *E-mail address: [email protected]
Abstract: We present the nano-scale correlation of morphology, structural and optical properties of GaN/AlxGa1-xN nanowires (NWs) as observed by a combination of spatially and spectrally resolved cathodoluminescence (CL) spectroscopy and imaging, scanning (SEM) and transmission electron microscopy. Characteristic luminescent properties of NWs with different composition and thickness of the AlxGa1-xN segment are discussed.
It is well established that III-N family nanowires (NWs) are promising building blocks for novel optoelectronic nano-devices including light-emitting diodes (LEDs) and lasers. Their main advantage over planar layers is high surface-to-volume ratio. Small contact area of NW with the substrate allows easy elastic accommodation of misfit strain and reduction of related extended defects, which is crucial for integration of GaN devices with Si technology. The good point is that the emission wavelengths of GaN/AlxGa1-xN NWs can be easily tuned by variations in the thicknesses and chemical composition of each component of heterostructure. GaN nanowires (600-800 nm long) with AlxGa1-xN segments and accompanying Al-rich shell surrounding the part of the nanowire below the AlxGa1-xN segment were grown on in-situ nitridised Si(111) substrates without any catalyst by plasma-assisted molecular-beam epitaxy [1]. To avoid intermixing on the GaN/AlxGa1-xN interfaces, between each segment of the nanowire a growth interruptions were applied. Aluminum content within AlxGa1-xN insets and shells was varied in subsequent samples. Morphology, structure and composition of the nanowires were examined with the use of scanning and transmission electron microscopy. Luminescent properties were studied with the use of low-temperature CL spectroscopy and imaging. CL measurements were performed for NW ensembles as well as for individual NWs dispersed onto silicon wafers. CL maps and linescans taken along the individual nanowires at temperature of 80 K have shown a strong localised luminescence in the core-shell region. Set of CL spectra taken along the individual GaN/Al0.2Ga0.8N NW is shown in Fig. 1, one can see a strong blueshifted near- band-edge emission (3.48-3.54 eV) of GaN core compressively strained by Al-rich shell [2]. Spectral features characteristic for NW ensembles and individual NWs with different composition and thickness of the AlxGa1-xN segment are discussed. Especially cathodoluminescence spectrum imaging allow to observe and analyse the strain existing in the core-shell region of the NWs. A B strained GaN AlGaN emission emission GaN
! AlGaN
#
GaN Distance [nm] % CL linescan DX - unstrained GaN NW 5 kV, 1.48 nA, 80 K 100 nm "# "#$ "$ "$$ "% "%$ "& "&$ "' "'$ "( rW Emission energy [eV]
Fig. 1. A) CL spectra series (linescan) taken along individual GaN/Al0.2Ga0.8N NW revealed strong blue- shifted GaN base emission just below the AlxGa1-xN segment of the NW B) SEM-TE image of the NW.
This work was partly supported by the Polish National Science Centre (NCN) Grant No. DEC- 2012/07/B/ST5/02484
[1] A. Wierzbicka et al. Nanotechnology 24, 035703 (2013) [2] L. Rigutti et al. PRB 83, 155320 (2011)
219 Oral-60
Cathodoluminescence studies of ZnO microrods grown by hydrothermal method
Agnieszka Pieni=bek [1], Bartomiej S. Witkowski [1], Anna Reszka [1], ukasz Wachnicki [1], Sylwia Gieratowska [1], Marek Godlewski [1,2], Bogdan J. Kowalski [1] [1] Institute of Physics, Polish Academy of Science, Warsaw, Poland 7 8 9 : L < - 2 E-mail address: [email protected]
Abstract: Optical properties of individual ZnO microrods prepared by microwave hydrothermal method were investigated by spatially and spectrally resolved cathodoluminescence (CL) spectroscopy and imaging at liquid-helium temperature. For properly chosen growth conditions the strong localization of CL emission at the corners of the individual hexagonal ZnO microrod (Fig. 1) was revealed. Locally distributed luminescence and fine structure of near-band-edge emission (Fig. 2) are discussed as a manifestation of whispering gallery modes (WGMs) of the hexagonal resonator occurring for the near band-gap luminescence in the ZnO microrods [1].
The ZnO micro- and nanostructures have attracted considerable attention because of their great application potential in micro- and nano-optoelectronics. Their excellent properties and geometrical characteristics make them a promising photonic material for optoelectronic devices. ZnO microrods with regular hexagonal cross-section can serve as small-sized optical resonators. The WGMs, which can be excited in them, have attracted much attention. The WGMs offer an attractive means to enhance luminescence efficiency in small-scale optical resonators. The paper proves that the optical properties of ZnO microrods grown by ultra-fast and inexpensive hydrothermal method can be modified in a controlled way by changes of the technological conditions (pH value, temperature, growth time and microwave power) [2]. The structures were grown on 3-) -thick GaN templates and studied by CL spectroscopy. As revealed by scanning electron microscopy ZnO microrods were vertically well aligned with length, diameter, and distribution density dependent on growth conditions. The light emission properties of ZnO microrods were investigated as the function of growth conditions, as well as the experimental conditions (such as excitation density, irradiated surface area, etc.) by spatially and spectrally resolved CL measurements. Near-band-edge emission and defect-related emission were observed from all samples but the shape, the energy and the intensity ratio of these two emissions strongly depended on the microrods properties (such as the dimension, morphology, surface/bulk ratio, etc.). CL measurements of individual ZnO microrods grown at properly chosen growth conditions showed enhanced luminescence intensity located at the corners of the microrods (Fig. 1) and set of separated fine structures superimposing near-band-edge emission (Fig. 2). These luminescence features can be attributed to the transverse mode enhanced emission in the resonant cavity M WGMs.
: // * V
: // ?[ /
~ ] _
Fig. 1. The monochromatic CL image at 369 nm of Fig. 2. CL spectrum collected from individual ZnO the individual ZnO microrod. microrod. Arrows signalize resonant peaks.
This work was partly supported by the Polish National Science Centre (NCN) Grant No. DEC- 2012/07/B/ST5/02484.
[1] S. Choi et al., Applied Physics Letters 103, 171102-1-171102-4 (2013). [2] B.S. Witkowski et al., Int. J. Nanotechnol. 11, 758-772 (2014).
220 Poster
Poster Session P-01-01
TheTh heterostructures (ZnO, n-GaN and i-Al2O3, i-HfO2)- electrical and sensor properties
E. Przezdziecka, S. Chusnutidinow, R. Schifano, E. Guziewicz, A. Reszka, M. Stachowicz, D. Snigurenko, A. Kozanecki Institute of Physics, Polish Academy of Sciences, Al. Lotników 32/46, 02-668 Warsaw, Poland E-mail address: [email protected]
Abstract: The hetrostructures consisting of ZnO:N,As/i-oxide/n-GaN layers with forward-to- 7 reverse current ratio IF/IR at about 10 , were successfully obtained by combining two growth methods (MBE and ALD). The position of the diode and the presence of the isolating layer was depicted and confirmed by electron beam induced current together with secondary electrons images and the diffusion length of carriers was extracted from the EBIC image. The obtained structure is sensitive to the UV light and the difference between the bright and dark current reaches four orders of magnitude. Additionally, the detection region was modified by the presence of a thin isolating layer deposited at the ZnO and GaN interface.
Zinc oxide (ZnO) is a promising candidate for applications as ultraviolet (UV) photodetectors due to its large direct band gap and the high absorption coefficient in the UV spectral range. UV detectors based on wide bandgap semiconductors as GaN and ZnO have recently received a lot of attention due to their chemical and thermal stability in harsh environment. In the case of ZnO the p-type doping is required for many applications. It is known, however, that the p-type doping of ZnO is a difficult task due to the background n- type centers. The structures consisting of acceptor doped ZnO:(N or As) films were grown by plasma-assisted molecular beam epitaxy (MBE) on n-type GaN on sapphire templates. In the case of p-i-n heterostructure a thin isolating Al2O3 or HfO2 layers ware deposited on GaN template by atomic layer deposition before the growth of ZnO layer by MBE. The concentration of nitrogen (arsenic) in ZnO, measured with secondary ion mass spectroscopy, are 1019-1020 at/cm-3 and acceptor-related lines in temperature dependence photoluminescence are observed. We show that the maximum forward-to-reverse current ratio IF/IR in the obtained diodes is relatively high (105-107) [1, 2] which is 2–5 orders of magnitude higher than previously reported values for this type of heterojunctions. The very low dark current of 10-11A and the high breakdown voltage (<-7V) are characteristic of this type of the obtained diodes. Electron Beam Induced Current (E- BIC) measurements confirmed the formation of the junctions[3] at the ZnO/GaN interface. The presence of isolating Al2O3 layers is also visible, with the E-BIC scan superimposed on cross-sectional SEM image, which is an unusual result. The diffusion length and activation energy of charge carriers have been calculated from E-BIC scan profiles. The optical parameters was investigated by luminescence and ctahodoluminescence. It was shown that heterostructures exhibit strong and selective absorption in the UV range and the photocurrent signal was modified by adding isolating layers at the interface which is in a good correspondence to CL results. The difference between the light and dark currents is above four orders of magnitude and it strongly depends on the powers of UV light. Presented structure are fast response time to UV light – in the case of junction it is 1-2 ms. The investigated structures are promising for UV sensor application.
The research was partially supported by the NCN project DEC-2013/09/D/ST3/03750 and DEC-2012/07/B/ST5/02484. The Author RS was supported by the EU 7th Framework Programme project REGPOT-CT-2013-316014 (EAgLE).
[1] E. Przezdziecka, M. Stachowicz, S. Chusnutdinow, R. Jakiea and A. Kozanecki, Appl. Phys. Lett. 106, 062106 (2015). [2] E Przezdziecka, S Chusnutdinow, E Guziewicz, D Snigurenko, M Stachowicz, K Kopalko, A Reszka and A Kozanecki J. Phys. D: Appl. Phys. 48, 325105 (2015). [3] L. Chernyak , C. Schwarz , E. Flitsiyan , S. Chu , J. L. Liu , and K. Gartsman , Appl. Phys. Lett. 92, 102106 (2008).
222 P-01-02
Super-resolution confocal microscopy based on radiallyll polarized beams and pupil filtering
Zhehai Zhou*, Lianqing Zhu Beijing Key Laboratory for Optoelectronic Measurement Technology, Beijing Information Science and Technology University, Beijing, 100192 E-mail address: [email protected]
Abstract: A scheme of super-resolution confocal microscopy based on radially polarized beams and pupil filtering is studied. The 3D optical transfer function and point spread function of a confocal microscopy using radially polarized beams and pupil filtering are first derived based on vector diffraction theory, and simulation results are presented to verify the feasibility of the scheme. Furthermore, the effects of the size of detector, the size of pin-hole and their position deviations on imaging performances are analyzed based on the theoretical models.
1. Introduction High spatial resolution optical measurement methods and techniques have become a major research topic in modern measurement areas. Some super-resolution imaging methods have been proposed to meet the urgent need of high resolution optical measurement, including 4Pi confocal microscopy, structured illumination microscopy (SIM), stimulated emission depletion (STED), Stochastic optical reconstruction microscopy (STORM), photo activated localization microscopy (PALM) and fluorescence photo-activation localization microscopy (FPALM). However, to some extent, these methods are complicated, expensive or cumbersome. So we propose a super-resolution imaging scheme based on a standard confocal microscopy, and radially polarized beams and pupil filtering are used in the scheme by use of the unique focusing properties of radially polarized beams and optical shaping technology. The 3D optical transfer function (OTF) and point spread function (PSD) are derived based on vector diffraction theory, and some simulation results are presented to verify the feasibility of super-resolution imaging. Meanwhile, the effects of system structure parameters, such as the size of detector, size of pin-hole, and their position deviations on imaging performances are analyzed. 2. Results According to the imaging principle of the confocal microscopy, the 3D PSF of a confocal microscopy is the product of the 3D PSF in object space and the 3D PSF in imaging space, huvtoi,,, huvhuv ġġġġġġġġġġġġġġġġġġġġġġġġġġġġ (1) And the intensity response function on the detector is written as, C 2 CSiu sin2 D CSvsin DT2 Iuv, DDTO l J exp sin cos d 0 1 DT2 D EUsin DT2sin E EU2 ġġġġġġġġġġġġġġġġġġġġ (2) 2 S CSiu sin2 CSvsin DT2 T O lJDTexp sin cos d T 0 1 DT2 EUsin DT2sin T EU2 U
2 1 CSiu 2expO PJvdDT 0 20EU2 Based on these equations, we can calculate the intensity response, and analyze the influences of structure parameters on imaging performances.
1 1
0.8 0.8
0.6 0.6 ⹎ ⹎ ⻢ ⻢
⊾ 0.4 ⊾ 0.4 ᶨ ᶨ 0.2 0.2
0 0 -2 -1 0 1 2 -2 -1 0 1 2 x () x () Figure 1 The intensity response on the detector for NA=0.90 (left) and 0.95 (right) References [1] M. Gu.. World Scientific, Singapore, 1-96 (1996). [2] Q. Zhan, Adv. Opt. Photonics 1, 1-57( 2009).
223 P-01-03
PhasePh Retrieval by using the Transport-of-Intensity Equation with Hilbert Transform
Wei-Shuo Li, Chun-Wei Chen, Kuo-Feng Lin, Hou-Ren Chen, Chih-Ya Tsai, Chyong-Hua Chen, and Wen-Feng Hsieh Department of Photonics and Institute of Electro-Optical Engineering, National Chiao Tung University, Hsinchu 300, Taiwan E-mail address: [email protected]
Abstract: Transport-of-intensity equation (TIE) is a non-iterative and non-interferometric technique for phase recovery. For solving the TIE with conventional, one partial derivative and Hilbert transform methods, we show that the Hilbert transform method can provide the smoother phase image and edge enhancement. Furthermore, it can quantitatively map out the phase images for both the periodic and aperiodic structures.
1. Introduction Phase imaging is a key technique for the inverse problem of optical measurement. The differential interference contrast (DIC) microscopy [1] records the information of phase gradient along the shear direction on the sample plane by intensity variation, and can enhance the edges and contour. To recover the phase images from DIC, integration along the shear direction is a direct approach, but it will introduce many streaks from the unknown constants. To solve this problem, some methods such as the one partial derivative (OPD) [2] and Hilbert transform (HT) [1] were proposed for recovering the phase gradient with eliminating the streaking. The transport-of-intensity equation (TIE) [3] is a non-iterative and non-interferometric phase retrieval technique, and the phase distribution can be determined from the measured intensities on the successive propagation-planes. During solving the TIE, there exists a gradient term of phase, and it usually need to solve by a 2D Poisson process using fast Fourier transform twice [3]. However, this is just equivalent to the case of DIC, so we can use the OPD or HT methods to replace this process. In this paper, we compare the phase images recovered by the conventional-TIE (c-TIE), OPD and HT methods for both the periodic and aperiodic samples. 2. Phase Retrieval Results We use two transparent samples in experiments, one is an aperiodic sample (dragonfly wing), and the other is a periodic sample (microlens array). The phase profiles along a vertical line on the dragonfly wing in Fig. 1(a) solved by the c-TIE, OPD and HT are shown in Fig. 1(b), (c) and (d), respectively. The c-TIE and OPD cases show a linear ramp and/or the oscillatory phase changes in membranes are far from the expected flat phase profiles. On the other hand, the HT result shows a flat phase distribution in membranes and a sharper phase change at the branch. The measured branch width is about 19.2 mQ which is close to the estimated value obtained from the optical image in Fig. 1(a). Furthermore, a reasonable good agreement of the HT-TIE results with the atomic force microscope measurement was obtained for a microlens array.
Fig.1. (a) Optical image of a dragonfly wing and its phase profiles along the marked line solved by the (b) c- TIE, (c) OPD and (d) HT. 3. Conclusion We have demonstrated the phase recovery by solving the TIE using the c-TIE, OPD and HT methods for both the periodic and aperiodic structures. The results show that the +#2&-" ! , .0-4'"# the smoother phase images with edge enhancement and fine structures. In addition, the HT-TIE can quantitatively map out the diameter and average height of a microlens array, which closely agrees with the results measured by the atomic force microscope. 4. References [1] M. R. Arnison, C. J. Cogswell, N. I. Smith, P. W. Fekete and K. G. Larkin, J. Microsc. 199, 79-84 (2000). [2] J. Matías Di Martino, Jorge L. Flores, Franz Pfeiffer, Kai Scherer, Gastón A. Ayubi, and José A. Ferrari, Opt. Lett. 38, 4813-4816 (2013). [3] M. R. Teague, J. Opt. Soc. Am. 73, 1434-1441 (1983).
224 P-01-04
Light-sheet microscopy for multi-plane holographic imaging
Xiaomin Zhai1 , His-Hsun Chen1, , Chen Zhi2,3, Dipanjan Bhattacharya3,4, and Yuan Luo1,5 1. Institute of Medical Devices and Imaging System, National Taiwan University, Taipei, 10051, Taiwan R.O.C. 2. Department of Biomedical Engineering, National University of Singapore, Singapore 3. Singapore-MIT Alliance for Research and Technology (SMART) Centre, Singapore 4. Centre for BioImaging Sciences (CBIS), National University of Singapore, Singapore 5. Molecular Imaging Center, National Taiwan University, Taipei, 10051, Taiwan R.O.C. *Corresponding author: [email protected]
Abstract: Light-sheet based microscopic techniques offer the ability to acquire optically sectioned fluorescence images with good background rejection for tissue imaging in wide- field fashion; however, none of these techniques have the capability to image multiple fluorescent planes at the same time. In this paper, we present an imaging scheme, incorporating side illumination with multiple light-sheets and multiplexed volume holographic gratings, to simultaneously obtain multi-plane images with optical sectioning capability, and no need for any axial scanning. The proposed imaging geometry is configured such that different depths inside an object are illuminated from side by multiple light sheets, and also serve as the input focal planes for subsequent multiplexed volume holographic imaging gratings. We present the design and implementation of the Light-sheet based microscopic, and provide experimental image data demonstrating the proposed system’s ability to obtain optically sectioned and multi-plane images of fluorescently labeled biological tissue samples.
References [1] Y. Luo, J. Castro, J. K. Barton, R. K. Kostuk, and G. Barbastathis, "Simulations and experiments of aperiodic and multiplexed gratings in volume holographic imaging system", Vol.18, No.18, OPTICS EXPRESS, 2010, 19273-19285 [2] A. Sinha, W. Sun, T. Shih, and G. Barbastathis," Volume holographic imaging in tramission geometry", Apply Optics, Vol.43, No.7, 2004, 1533-1551 [3] Y. Luo, P. J. Gelsinger-Austin, J. M. Watson, G. Barbastathis, J. K. Barton, and R. K. Kostuk, " Laser- induced fluorescence imaging of subsurface tissue structures with a volume holographic spatial-spectral imaging system", Vol.33, No.18, OPTICS LETTERS, 2008, 2098-2100
225 P-01-05
Non-axial-scanningN multifocal confocal imaging with volume holography
Po-Hao Wang,1,2) and Yuan Luo 1,2) 1) Institute of Medical Device and Imaging, National Taiwan University, Taipei 10051, Taiwan, R.O.C 2) Molecular Imaging Center, National Taiwan University, Taipei, 10672, Taiwan, R.O.C E-mail: [email protected]
AbstractĻġ Wide-field fluorescence microscopy is a commonly used imaging technique by researchers and clinicians. A standard wide-field microscope has no optical sectioning capabilities and this limits its use in imaging thick biological samples. Although standard wide-field fluorescence microscopy with deconvolution techniques can improve image quality [1], it does not provide true optical sectioning, due to the missing cone in system’s transfer function. The most commonly used optical sectioning imaging method with good background rejection in biomedicine is based on the confocal approach [2-4]. However, the price to pay for improved image quality in 3D confocal microscopy is a point-by-point scan time that is proportional to the number of desired voxels (i.e. the 3D space-bandwidth product). Here, we demonstrate the first experimental realization of a non-axial-scanning multi-focal confocal microscope for 3D imaging where contrast and speed are achieved from a combination of confocal imaging pinholes and multiplexed holographic Bragg illumination filters.
Figure 1: Schematic drawing of the proposed Figure 2: Experimental measurement of point- microscope. spread function at different planes. References: [1] McNally, J.G., Karpova T., Cooper, J., Conchello, J.A., Three-dimensional imaging by deconvolution microscopy, Methods 19, 373-385, 1999. [2] C.J.R. Sheppard, A. Choudhury, “Image Formation in the Scanning Microscope”, Optica Acta, Vol. 24,ġ No.10, pages 1051-1073, 1977. [3] M.Minsky, “Memoir on inventing the confocal scanning microscope”, Scanning, Vol. 10, Issue 4, pages 128–138, 1988 [4] Yuan Luo, Vijay Raj Singh, Dipanjan Bhattacharya, Elijah Y. S. Yew, Jui-Chang Tsai, Sung-Liang Yu, Hsi-Hsun Chen, Jau-Min Wong8, Paul Matsudaira, Peter T. C. So and George Barbastathis, "Talbotġ Holographic Illumination Non-scanning (THIN) Fluorescence Microscopy," Laser & Photonicsġ Reviews ,Volume 8, Issue 5, pages L71–L75, September 2014.
226 P-01-06
Tip-enhanced Near-field Optical Microscopy Based on a Plasmonic Lens/ Probe
Mingqian Zhang QianXuesen Laboratory of Space Technology, China Academy of Space Technology, Beijing 100094, China E-mail address:[email protected]
Abstract: Tip-enhanced near-field optical microscopy is a promising scanning probe technique for exploring near-field optical properties of individual objects and structures on the nanoscale. It is capable of obtaining corresponding topographical and optical information with resolution beyond the diffraction limit and grants remarkable localized optical signal enhancement. This technique uses a sharp metallic tip regulated in the near-field of a specimen’s surface, which is illuminated with a proper excitation field meeting the excitation conditions of the wave-vector matching. The local optical field interacted with the specimen in the vicinity of the tip apex is effectively enhanced. In this technique, the signal enhancement near the antenna is attributed to the excitation of localized surface plasmons and the lighting-rod effect. Typically, a tip-enhanced near-field optical microscope is composed of a scanning probe microscope, excitation/ collection optical configuration, and a detection device. In this technique, how to optimize the tip-excitation field coupling to improve the detection sensitivity is of crucial importance and receives great research attentions. In this work, two kinds of methods are presented to improve the signal to noise ratio of tip- enhanced near-field optical microscopy by both strengthen the near-field optical signal enhancement and reducing the far-field background noise. First, a tip-enhanced near-field optical microscope based on a plasmonic lens is investigated. A symmetry-breaking strcture plasmonic lens is specifically designed for focusing the surface evanescent wave and generates a longitudinal field dominated excitation field. The focusing property of the longitudinal field by the plasmonic lens is theoretically simulated and experimentally investigated. It is demonstrated that the plasmonic lens is suitable for providing the longitudinal field excitation foe local field enhancement on a tip antenna. Then, the plasmonic lens is utilized in the excitation configuration of the tip-enhanced near-field optical microscope to replace a conventional objective lens. Second, a plasmonic probe which consisted of a taper cylinder tip and a couple of curved nanoslits on the probe base was designed. It is suitable to be used in top-illumination mode tip-enhanced near-field optical microscope to isolate the focused near-field excitation at the probe apex from the contribution of the far-field illumination. The field enhancement and the confinement performance of the probe were investigated using three-dimensional finite-difference time-domain method. The structure of the probe was optimized and fabricated with FIB method. The field enhancement performance of the plasmonic probe was theoretically simulated and experimentally detected.
[1] M. Zhang, J. Wang, “Plasmonic lens focused longitudinal field exctation for tip-enhanced Raman spectroscopy,” Nanoscale Research Letters. 10, 189 (2015). [2] M. Zhang, J. Wang, “Metallic probe with integrated symmetry-breaking nanoslits for enhanced nanofocusing,” Plasmonics. 10, 5 (2015).
227 P-01-07
NearN Field Photoluminescence Imaging of Isolated P3HT Polymer Chains
He-Chun Chou1, Tai-Chun Liu1,2, Peilin Chen1, Chi Chen1* 1Research Center for Applied Science, Academia Sinica, Taipei, Taiwan 2Department of Materials Science and engineering, National Dong Hwa University E-mail address: [email protected]
Abstract: Microscopic interaction between polymer chains leads to various macroscopic morphology of polymer blends and further determines the efficiency of organic photovoltaic devices. Near-field scanning microscopy (NSOM) is a powerful characterizing tool to investigate such structural factors on the devices’optoelectronic performance. In this report, we use silicon cantilever with nanofabricated aperture to probe the local photoluminescence (PL) of poly(3-hexylthiophene) (P3HT) isolated polymer chains. We have successfully applied high special resolution near-field mapping to correlate the PL intensity and the film morphology. Our NSOM resolution is 75 nm from PL mapping while the spatial resolution of AFM morphology is 50 nm. In addition, different vibronic features in PL spectrum correlated to different chain morphologies are observed.
Conjugated polymers are excellent materials for cost-effective photovoltaic solar cells and flexible optoelectronic devices. However, the efficiency of organic solar cell is still a problem, and it is highly related to local properties such as morphology and photoluminescence(PL) of the thin film nanometer scales. Near- field scanning microscopy (NSOM) has been applied to study those properties simultaneously [1,2]. Here, we modified a commercial NSOM system and utilized apertured silicon cantilever to investigate local properties of conjugate polymer. We spin-coated 10-8 M poly(3-hexylthiophene) (P3HT) solution on mica and study the relation between morphology and PL. Both spectral peak shift and ratio change between two vibronic peaks provide the information of microscopic interaction between polymer chains.
Fig. 1 (a) Schematic illustration of microscopic PL from P3HT and the apertured NSOM system (b) The AFM topography of isolated polymer chains of P3HT Scan size: 5 m ×5 m, 256 pixels×256 pixels. (c) The corresponding near-field PL mapping by photomultiplier (PMT). Scan size: same as (b), 128 pixels×128 pixels. (d) The cross section along the red line in (b) and (c) respectively, black line is from topography and blue dash line is from PL mapping. (e) Near-field PL spectrum of different spots along the black line in (c). References [1] X. Wang, D. Zhang, K. Braun, H. Egelhaaf, C. J. Brabec, A.J. Meixner, Adv. Funct. Mater. 20, 492-499, (2010) [2] P. F. Barbara, D. M. Adams, D. B. O’Connor, Annu. Rev. Mater. Sci. 29, 433-469 (1999).
228 P-01-08
Adsorption and Release of Photodynamic Dyes by Zeolitelit Nanoparticles
Vladimir Hovhannisyan, Chen Yuan Dong Department of Physics, National Taiwan University, Taiwan E-mail address: [email protected]
Abstract: Nanoparticles are effective carriers for cancer-targeted drug delivery. One of the promising materials for biomedicine are natural zeolite nanoparticles (ZNPs) due to non- toxicity, large external surface area and exceptional ability to adsorb various molecules and atoms in their nanopores. We demonstrate that ZNPs produce two-photon excited luminescence (TPEL) and second harmonic generation (SHG) at infrared fs irradiation. Multiphoton imaging shows that individual ZNPs adsorb hypericin (Hyp), porphyrin derivatives (PD) and other photo-dynamically active dyes. Furthermore, the release of dyes from the ZNP pores in the presence of biomolecules such as bovine serum albumin, collagen, human hemoglobin or lipids is demonstrated. Nonlinear microscopy and spectroscopy may open new perspectives in the research and application of ZNPs and help to introduce novel approaches into biomedical optics and clinical environment.
1. Introduction Drug transportation and delivery of bioactive compounds are popular in biomedicine and clinical research for years [1]. The most important requirements to transporters are their non-toxicity, high biocompatibility, stability and adsorption-desorption properties. Based on these criteria, the clinoptilolite type of natural zeolite (CZ) can be considered as perfect candidate for biomedical applications. Zeolites are crystalline aluminosilicates consisting of oxygen-sharing SiO4 and AlO4 tetrahedral groups united by common vertices in three-dimensional framework and containing pores with diameters from 0.3 to 1.2 nm. The maximum of luminescence excitation spectrum of CZ locates near the 285 nm [2]. In this UV spectral region the linear absorption and scattering of CZ samples are very strong and non-favorable to perform conventional optical imaging or spectroscopic measurements. Here, the first attempt to apply multiphoton microscopy (MPM) with 720-900 nm excitation wavelength ( exc) to image and study the interaction of CZ nanoparticles (ZNPs) with some photodynamic dyes is presented. 2. Results Using MPM we registered TPEL of ZNPs (Fig. 1A, exc<745 nm), and a strong SHG (Fig.1B, 760 nm < exc<800 nm). MPM of a drop of PD solution before (Fig. 1C, exc=780 nm) and after addition of ZNPs (Fig. 1D, exc=780 nm) showed that the dye molecules adsorbed by ZNPs. Similar multiphoton imaging revealed that cationic photodynamic dyes (methylene blue, chlorine, phthalocyanines) adsorbed by ZNPs, whereas fluorescein – an anionic dye was not adsorbed, and the TPEL image of the dye solution had even distribution in the presence of ZNPs. Furthermore, it was demonstrated that Hyp adsorbed by ZNPs very well in water solution, however released from particle pores during 50 minute when biomolecules such as bovine serum albumin, collagen, human hemoglobin or lipids were added to the ZNP+Hyp system. These results indicate that ZNPs can be successfully used for drug delivery in photodynamic therapy and fluorescence diagnosis.
Fig. 1. MPM of ZNPs (A, B), pure PD (C) and PD after the addition of ZNPs (D). Green pseudocolor is TPEL of ZNPs (A) and PD (C and D) detected by the 420-650 nm registration channel, and red pseudocolor is SHG signal from ZNPs (B and D) detected by the 380-400 channel. 3. References [1] T. R. Kuo, V. A. Hovhannisyan, Y.C. Chao, et al., J. Am. Chem. Soc., 132, 14163-14171 (2010). [2] H. N. Yeritsyan, V. Harutiunian, V. Gevorkyan, et al., CEJP 3, 623-635 (2005).
229 P-02-01
EnhancementEh of the field intensity of switchable surface plasmon subwavelength focusing and bi-directional vortex
Chung-Ying Lin and Chen-Bin Huang* Institute of Photonics Technologies, National Tsing Hua University, Hsinchu 30013, Taiwan Email: [email protected]
Abstract: We demonstrate for the first time that dynamic controls to surface plasmon subwavelength focusing or bi-directional vortex creations can be achieved simply through changing the orientations of linearly-polarized optical excitations. In addition, we efficiently enhance field intensity by using dislocated arrangement of nanocavities.
1. Introduction Recently, the ability to generate SP vortex or subwavelength focusing in plasmonic Archimedes spiral/slots has attracted immense research attentions [1-3]. The functionality of such plasmonic device is to allow the conversion from far-field optical spin angular momentum (SAM) to near-field optical angular momentum (OAM) due to its chirality. We recently demonstrated the first controllable trapping or rotation of micro-particles using such spiral device [3]. However, this sets two major limitations: (1) SP vortices or subwavelength focusing requires circularly polarized excitations of different handedness; and (2) It would not be possible to control the rotation direction of the SP vortex in a given plasmonic spiral. To alleviate the first limitation, we recently demonstrated a properly designed plasmonic metasurface could be used to dynamically create SP vortex or subwavelength focusing, purely through linearly polarized optical excitations [4]. In the current presentation, we extend our findings to alleviate the second limitation. We numerically demonstrate the ability not only to create SP subwavelength focusing, but also bi- directionally tunable SP vortices in a designed metasurface under linearly polarized optical excitations that carry absolutely no angular momenta. Moreover, we envision major impacts in selectable motional control of nanoparticles and opto-fluidics. In order to make this design be able to do selectively micro-particles trapping or rotation, the force need to be strong enough. By dislocated arranging the twenty length-optimized nanocavities in the geometry of circle, we could efficiently enhance the field intensity of surface plasmon subwavelength focusing and vortex at least larger than one order. 2. Figuresg
Figure 1. The instantaneous phase (a), and the line phase plot Figure 2. (a) (c) Schematics of the metasurface. (b) (d) Field (b) under 45° linearly-polarized excitation. The corresponding intensity in x-direction. results under -45° linearly-polarized excitation are shown in (c) and (d). 3. References [1] H. Kim, J. Park, S.-W. Cho, S.-Y. Lee, M. Kang, and B. Lee, Nano Lett. 10, 529 (2010). [2] C.-D. Ku, W.-L. Huang, J.-S. Huang, and C.-B. Huang, IEEE Photon. J. 5, 4800409 (2013). [3] W.-Y. Tsai, J.-S. Huang, and C.-B. Huang, Nano Lett. 14, 547 (2014). [4] C.-F. Chen, C.-T. Ku, Y.-H. Tai, P.-K. Wei, H.-N. Lin, and C.-B. Huang, Nano Lett. 15, 2746 (2015).
230 P-02-02
Three Dimensional Light Manipulation for Full-Colorl Nano-Projector
Mu Ku Chen1*, Chia Min Chang1,3, Ming Lun Tseng1, Cheng Hung Chu2, You Zhe Ho1, and Din Ping Tsai1,2 1Department of Physics, National Taiwan University, Taipei 10617, Taiwan 2Research Center for Applied Sciences, Academia Sinica, Taipei 11529, Taiwan 3Graduate Institute of Photonics and Optoelectronics, National Taiwan University, Taipei 10617, Taiwan *E-mail address: [email protected]
Abstract: Using plasmonic nanostructures to manipulate the scattered light from the SPP waves will be experimental demonstrated. The surface plasmon waves can be scattered and modified by various plasmonic structures composed of gold nanobumps. The height and intensity profile of the focusing patterns are precisely controlled in three-dimensional space by the curved arrangement of nanobumps which are 300nm heigh. The modulation of the projecting height of the focusing pattern is reached as high as 10 um. The intensity profile of focusing pattern can be approached to a diffraction-limited spot. The projecting image constructed by focusing spot from designing nanobumps arrangement is achieved in three- dimensional space.
1. Introduction The Au nanobumps confer additional three-dimensional propagating wave vectors on SPP wave for departing from surface. It is possible to manipulate the three-dimensional plasmonic scattering by arranging the Au nanobumps. In this work, we manipulate the scattering of SPP waves by various plasmonic structures composed of arranged nanobumps on a gold thin film. Upon controlling the geometry of the plasmonic structures, the height, position, and pattern of scattered light can be modified as desired. It provides a simple and efficient way to project a specific light pattern into free space, and demonstrate the capability of three- dimensional light manipulation. By precisely designing a particular curved structure with appropriate radius of curvature and adjacent interspacing of nanobumps, we can construct a clear single focusing spot at a specific altitude. The irregular light patterns of the scattering of designed structures are observed at any observation plane, except for the scattering-light-focal plane where observing the focusing spot of curved structure. When the focal plane is shifted to this scattering-light-focal plane, the “NTU” light patterns are clearly observed. Under the different color laser which are green, blue and red illuminating, the “NTU” pattern are observed with different color respectively. Figure 1 shows the”NTU” pattern is illuminated by RGB laser. These results confirm the controllability of the focused spot in three-dimensional space by settling curved structures. 2. Figures
Figure: Images of the NTU pattern which is illuminated by RGB laser.
[1] C. M. Chang, C. H. Chu, M. L. Tseng, Y.-W. Huang, H. W. Huang, B. H. Chen, D.-W. Huang, and D. P. Tsai, "Light manipulation by gold nanobumps," Plasmonics 7, 563-569 (2012). [2] C. M. Chang, M. L. Tseng, B. H. Cheng, C. H. Chu, Y. Z. Ho, H. W. Huang, Y.-C. Lan, D.-W. Huang, A. Q. Liu, and Din Ping Tsai, "Three-dimensional plasmonic micro projector for light manipulation," Advanced Materials 25, 1118-1123 (2013).
231 P-02-03
AluminumAl Metasurface Based Multi-Polarization State Generator in Visible Frequency
Ting-Yu Chen1,*, Wei Ting Chen1, Wei-Yi Tsai1, Ching-Fu Chen1, Yao-Wei Huang1 and Din Ping Tsai1,2 1Department of Physics, National Taiwan University, Taipei 10617, Taiwan 2Research Center for Applied Sciences, Academia Sinica, Taipei 11529, Taiwan E-mail address: [email protected]
Abstract: An aluminum-based all-reflective polarization state generator is presented in visible spectrum region. We numerically and experimentally demonstrated the generation of six kinds of polarizations with rotated antennas under illumination of linear polarized light based on the mechanism of Pancharatnam-Berry phase.
Metasurfaces show the abilities to manipulate the phase and polarization of electromagnetic waves. Its optical properties are related to their geometrical structures instead of their constituent material. These advances have led to flat optical devices such as quarter waveplate, half waveplate [1]. In addition, the majority of previous works about polarization conversion are employed mostly in near-infrared because phase modulation is difficult to be realized in visible spectrum for gold and silver. Interestingly, aluminum with higher plasma frequency has recently been studied to yield surface plasmon resonances across a broader range of the spectrum spanning from visible to UV [2]. Here, we present both numerically and experimentally an aluminum-based reflective polarization state generator to produce six kinds of polarizations with high efficiency in the visible spectrum as shown in figure 1. A single antenna is consisted of three layers: a metal plane, a spacer layer, and antennas on the top. The ground metal plane not only block all transmissions light to full control the light , but also couples with the antenna and creates magnetic resonances then to get more ability of modulate the phase. All simulations are conducted with finite-difference time-domain (FDTD) software. Notably, the resonance spans over the entire visible region. Next, we gradually rotate the direction of antennas from 0 to 180 degrees to form the unit cell. During normal incidence of circularly polarized light, neighboring antennas with a rotation angle will induce a 2 phase difference while conversion efficiencies are the same since their geometries remain unchanged. Therefore, an incidence of linear polarization will create two circularly polarized reflection beams with opposite handedness in two different directions simultaneously, where the reflection angle - Ɣ ͯͥ 1', ʚ ͆3ʛ. When a linear polarization is incident to the unit cell and its counterpart arranged side by side, both LCP and RCP can be observed in the same direction. Meanwhile, a displacement d between the unit cell and its reversed counterpart is implemented to yield an additional phase delay <Ɣ"1',ʚ-ʛ ƔT͆͘ 3 between reflected LCP and RCP. Therefore, arbitrary linear polarizations can be generated. At last, we integrate the super cells together to generate six kinds of polarizations, including left circular polarization (LCP), right circular polarization (RCP), linear horizontal polarization (LHP), linear vertical polarization (LVP), linear +45° polarization (L+45P), and linear -45° polarization (L-45P) in one single chip.
Fig. 1. Schematic of the polarization state generator.
[1] N. Yu, F. Aieta, P. Genevet, M. A. Kats, Z. Gaburro, and F. Capasso, Nano Lett. 12, 6328-6333 (2012). [2] Y. -W. Huang, W. T. Chen, W. -Y. Tsai, , P. C. Wu, C. -M. Wang, G. Sun, and D. P. Tsai, Nano Lett. 15, 3122-3127 (2015).
232 P-02-04
Dual Channel Fluorescence Radiation Engineering on Plasmonic Metasurface
Hui Jun, Wu1*, Ming Lun, Tseng2, Wei-Yi, Tsai2, Ting-Yu Chen 1, and Din Ping Tsai1,2 1Department of Physics, National Taiwan University, Taipei 10617, Taiwan 2Research Center for Applied Sciences, Academia Sinica, Taipei 11529, Taiwan * Email: [email protected]; Tel.: +86-(02) 2787-3197
Abstract: Here we demonstrated that the upconversion fluorescence intensity and lifetime could be engineered by tuning the overlap between the electric and magnetic resonance frequency of the metasurface and the absorption/emission band of the upcovnersion nanocrystals. We found that over ten times enhancement of the fluorescence intensity could be achieved when the electric resonance frequency of the metasurface matches with the absorption band of the upconversion nanocrystals, while the magnetic mode overlaps with its emission band. The detailed results and mechanism will be discussed.
Upconversion fluorescence from Lanthanide-doped nanocrystals has attracted widespread interests because of its greatly potential applications in various fields, such as photonic crystal lasers, material science, biological therapy, and so on. However, the relatively low quantum yield (typically < 5%) is the major limitation for upconversion nanocrystals. Meanwhile, in addition to the chemical methods, plasmonic structures have been adopted as another strategy to improve the radiation efficiency and control the relaxation process of the upcovnersion nanocrystals [1-3]. We designed the anti-symmetric split ring resonators with various periods ranging from 250nm to 400nm. The surface plasmon resonance peaks of the structure shift as the periods varies. For example, in a multi- layered plamsonic metasurface with the period of 250nm, both the electric and magnetic modes could be generated simultaneously when excited by the incident light with proper polarization. This plasmonic structure provides two different channels for the enhancement of upconversion fluorescence. The resonance peak of 650nm is magnetic resonance mode, while the peak of 980nm is electric resonance mode, as shown in Fig.1. The resonance peak of 980nm coincides with the absorption band of the Lanthanide-dopoed nanocrystal, and the peak of 650nm matches with its emission band. We found that the upconversion fluorescence intensity could be enhanced more than 10 times when the electric resonance frequency of the metasurface matches with the absorption band of the upconversion nanocrystals, while the magnetic mode overlaps with its emission band. This is due to the local density of optical states was significantly enhanced by the plasmonic metasurface. The detailed results and mechanism will be discussed.
Figure. 1. Absorption spectrum of anti-symmetric Figure. 2. Upconversion fluorescence intensity on split ring resonators. The inset shows the field the glass, and antisymmetric split ring resonator distribution at 650nm and 980nm, respectively with x and y illumination, respectively
[1] K. Tanaka, E. Plum, J. Y. Ou, T. Uchino, and N. I. Zheludev, “Multifold enhancement of quantum dot luminescence in plasmonic metamaterials” Phys. Rev. Lett. 2012,105, 227403 [2] Dylan Lu, Jimmy J.Kan, Eric E. Fullerton and Zhaowei Liu, “Enhancing spontaneous emission rates of molecules using nanopatterened multilayer hyperbolic metamaterials,” Nature Nanotechnology, 2014,9,48-53 [3] Felicia Tam , Glenn P. Goodrich , Bruce R. Johnson , and Naomi J. Halas, “Plasmonic Enhancement of Molecular Fluorescence”, Nano Letter,7,495-501
233 P-02-05
Goos-Hänchen shift in nonlocal metal film
Wenjing Yu1 and Lei Gao1,* 1College of Physics, Optoelectronics and Energy of Soochow University, & Collaborative Innovation Center of Suzhou Nano Science and Technology, Soochow University, Suzhou 215006, China, 2Jiangsu Key Laboratory of Thin Films, Soochow University, Suzhou 215006, China. Email: [email protected].
Abstract: We investigate the Goos-Hänchen (G-H) shift reflected from an Au film for both normal and oblique incidence. It is found that the shift can be influenced by nonlocal effect and the influence is significant especially in the range above the plasma frequency. The nonlocal effect not only can affect the numerical size, but also can change the sign of the shift. We also study the impact of the thickness of film, incident angle and the incident frequency on the shift. There is also the numerical simulation which confirmed with the theoretical result.
234 P-02-06
Optical Multiple Bistability in Metal-Insulator-Metalt l Plasmonic Waveguides Side-coupled with Twin Resonators
Ruei-Cheng Shiu1, Guang-Yu Guo1, Yung-Chiang Lan2 1Department of Physics, National Taiwan University 2Department of Photonics, National Cheng Kung University E-mail address: [email protected]; [email protected]
Abstract: We investigate the resonant transmissions of surface plasmons that propagate in a metal-insulator-metal (MIM) waveguide side-coupled to two MIM racetrack resonators in which optical 3rd order nonlinear material is filled, by the coupling mode analyses and finite- difference time-domain simulations. We find the multiple bistabilities and the hysteresis phenomena in the transmission coefficient as the input intensity varies. Furthermore, the mode conversion between the bistable states can be controlled by varying the input-gate intensity with a short switching time of about 333 fs.
Nonlinear and switchable metamaterials, two kinds of the emergent materials of great interest [1], have widely been applied in nano-devices such as optical switches, rewritable memories, and logic operators. Metal-insulator-metal (MIM) plasmonic waveguides are a fundamental structure for surface plasmon polariton propagation, and provide low-loss propagation in a wide range of frequency. Therefore, several investigations based on MIM plasmonic waveguides to realize bistable effect in switchable systems with a nonlinear optical material have been reported recently [1-4]. We build up a structure composed of a MIM plasmonic waveguide and two racetracks filled with optical Kerr nonlinear material to realize the multi- bistable effect. We consider two racetrack resonators side-coupled to a silver MIM plasmonic waveguide as shown as Fig. 1 (a). The resonators are filled with a Kerr nonlinear material, whose relative permittivity ( d) 2 (3) 2 (3) depends on the local intensity of electric field |E| : d= 0 + |E| , where 0 and are linear relative permittivity and third-order nonlinear susceptibility. In our simulations, the Drude model with the plasma 16 14 frequency ( p) and electron collision frequency ( d) set to 1.255×10 and 0.68×10 . A TM-polarized plane wave (input-signal), of which the magnetic field is perpendicular to the x-y plane, is incident onto the waveguide from one end [Fig. 1 (a)], and the wavelength is 1540 nm.
Fig. 1 (a). Illustration of our proposed plasmonic waveguide. (b) Transmission spectra of the first (red line) and second (blue line) racetrack resonators. (c) Transmission efficiency as a function of the power of input.
First of all, we find that the eigen-wavelength of the first and second resonators are 1506 nm and 1495 nm respectively, as shown in Fig. 1(b). In addition, such structure has a strong resonance, Q1 = Q2 = 72, in the nonlinear resonators at the signal wavelength, which can enhance the nonlinear Kerr effect. As a result, we choose 1540 nm as the signal wavelength. Based on our FDTD simulations, the multi-bistable effect is presented in Fig. 1(c), and the blue (green and red) line and points indicate that the power of the input-signal increases from 0 (decreases from 24 MV2/cm2 and decreases from 10 MV2/cm2). In Fig. 1(c), (i), (ii), (iii), and 2 (iv) are the contours of |Hz| normalized by the input power when the signal power increases to 7.8, 8.6, 12, and 16.4 MV2/cm2, respectively. In this study, we have investigated the optical multi-bistable effect in two racetracks filled with an optical Kerr material on one side of a MIM plasmonic waveguides by two- dimensional FDTD simulations. Because of its multi-bistable effect, such system may find technological applications in multi-switches, optical logic operations, or even optical devices. Reference [1] N. I. Zheludev, Science 328, 582-583 (2010) [2] X. Wang, H. Jiang, J. Chen, P. Wang, Y. Lu, and H. Ming, Opt. Express 19, 19415–19421 (2011). [3] Y. Shen and G. P. Wang, Opt. Express 16, 8421–8426 (2008) [4] X. S. Lin, J. H. Yan, Y. B. Zheng, L. J. Wu, and S. Lan, Opt. Express 19, 9594–9599 (2011).
235 P-02-07
A LLagrange RLC Circuit Model for Split-ring Resonators
Hsun-Chi Chan1, Guang-Yu Guo1,* 1Department of Physics, National Taiwan University E-mail address: [email protected]
Abstract: We introduce a Lagrangian for a single split-ring resonators and find that this system possesses the bianisotropic constitutive relations. Based on the S-parameters calculated by finite element method, we can obtain the effective parameters by means of the bianisotropic retrieval method. In order to understand the mathematical structure, we also derive the transfer matrix method for bianisotropic media. Finally, the retrieved effective parameters all show the Lorentzian line shaped as expected.
Metamaterials are the artificially fabricated materials with unusual optical properties. In particular, left- handed metamaterials that have simultaneously negative electric permittivity and magnetic permeability have many exotic properties such as negative index of refraction [1]. Above all, metallic wires [2] and split- ring resonators (SRRs) [3] are two key structures to achieve negative and respectively. Together with these two structures, the first negative-index metamaterials (NIMs) were experimentally verified in the microwave region [4]. Different designs were proposed such that the working bands are pushed toward the visible region [5]. Liu et al. in 2010 proposed a Lagrange model for stereo-metamaterials (metamaterials that have same constituent units but with different orientation) to investigate its chiral optical properties [6]. Aside from usual numerical simulation methods such as finite-difference time-domain method (FDTD) and finite element method (FEM), the Lagrange model provides us a deeper insight into the mechanism of a metamaterial system. Inspired by this work [6], here we introduce a Lagrangian, which can be written as L 22 2 44 TV LQ()/20 Q) pE mB, for a single SRR interacting with an incident electromagnetic (EM) wave. First, we consider single SRR as an RLC circuit. In an SRR, the metal ring and the slit correspond to an inductor (L) and a capacitor (C), respectively. Depending on the orientation and polarization of the incident EM wave, we also take the electric and/or magnetic dipole interaction into account, which is the origin of the presence of the effective and . Then we take the oscillating charge Q and induced current Q as two independent generalized coordinates. By substituting the Lagrangian into the Euler-Lagrange equation and solving the equation of motion, we obtain the frequency-dependent Q and hence the effective and . Most significantly, we find that such system possesses the bianisotropic constitutive relations, and the forms of , , and¯ (the magnetoelectric coefficient) are just the Lorentzian line shapes as described in the literatures [3,7,9]. Finally, we use our model to fit two well-know examples, the fishnet structure [8] and single SRR [9]. The benchmark numerical results agree well with our model. This method can also be used to investigate other more complicated systems. References [1] V. G. Veselago, Sov. Phys. Usp. 10, 509 (1968). [2] J. B. Pendry, A. J. Holden, W. J. Stewart, and I. Youngs, Phys. Rev. Lett. 76, 4773 (1996). [3] J. B. Pendry, A. J. Holden, D. J. Robbins, and W. J. Stewart, IEEE Trans. Microwave Theory Tech 47, 2075 (1999). [4] R. A. Shelby, D. R. Smith, and S. Schultz, Science 292, 77 (2001). [5] C. M. Soukoulis, S. Linden, and M. Wegener, Science 315, 47 (2007). [6] H. Liu, J. X. Cao, S. N. Zhu, N. Liu, R. Ameling, and H. Giessen, Phys. Rev. B 81, 241403 (2010). [7] D. R. Smith, W. J. Padilla, D. C. Vier, S. C. Nemat-Nasser, and S. Schultz, Phys. Rev. Lett. 84, 4184 (2000). [8] S. Zhang, W. Fan, K. J. Malloy, S. R. Brueck, N. C. Panoiu, and R. M. Osgood, Opt. Express 13, 4922 (2005). [9] C. E. Kriegler, M. S. Rill, S. Linden, and M. Wegener, IEEE J. Sel. Top. Quantum Electron., 16, 367 (2010).
236 P-02-08
Chiral Metasurface for Circular Polarization Detectionti
Pei Ru Wu1*, Wei-Yi Tsai1, Wei Ting Chen1, Chun Yen Liao1, Greg Sun2, Peter Török3, Din Ping Tsai1,4 1 Department of Physics, National Taiwan University, Taipei 10617, Taiwan; 2 Department of Engineering, University of Massachusetts Boston, Boston, Massachusetts 02125, USA 3 Blackett Laboratory, Department of Physics, Imperial College London, London SW7 2BZ, UK 4 Rearch Center for Applied Sciences, Academia Sinica, Taipei 11529, Taiwan E-mail address: [email protected]
Abstract: Optical response of nature materials is very weak under different handedness circular polarization illumination. Therefore, we presented a metasurface which has strongly interaction with circular polarization to distinguish different handed circular polarized light and wavelength of the incident light through diffraction angles.
The sapphire and quartz can distinguish the s- and p-polarization, but the right-handed circular polarization (RCP) and left-handed circular polarization (LCP) can’t be separated by natural material easily [1]. However, the LCP and RCP are crucial to identify molecular in terms of drug development. For instance, there are two optical isomers: R-Thalidomide and S-Thalidomide, each isomer possesses different absorption under RCP and LCP illumination. R-Thalidomide is a kind of drug for pregnant women, and S-Thalidomide is toxic and cause phocomelia. The metasurfaces, an array of subwavelength antenna with varying sizes, show the abilities to manipulate phase, amplitude and polarization of incident light [2-4]. According to the Pancharatnam–Berry phase method, the phase distribution is achieved by rotating the nanorod, and the working frequency of our device is tunable by tailored the parameters of the nanorods. By adequately engineering the phase distribution of our device, the different handed circular polarization generation can be achieved and can be detected on one side by CCD. The multifunctional metasurface is fabricated with standard e-beam lithography on a quartz wafer. Figure 1 shows the scanning electron microscope (SEM) image of our metasurface. In this paper, we present a metasurface that integrates optical functionalities of grating, mirror and circular polarized light analyzer into a tiny device. It can split the different handed circular polarization and its efficiency is higher than that of the transmittance type. Our multifunctional metasurface shows in figure 2. The metasurface can separate RCP and LCP, and projecte them into two well-distinguished regions with pre- determined angle. The white light can be separated into space with different wavelength as well.
Fig. 1. The scanning electron microscope (SEM) image of our metasurface.
Fig. 2. Illustration of our metasurface under linear polarization illumination.
[1] Hecht, E., [Optics], Addison Wesley (2002). [2] N. Yu et al., Science 334, 333-337(2011). [3] S. Sun et al., Nano Letters 12, 6223–6229(2012). [4] W. T. Chen et al., Nano Letters 14, 225-230(2014).
237 P-02-09
High-sensitivityH Refractive Index Sensor Based on Plasmonic VSRR Structure
Jia-Wern Chen1,*, Pin Chieh Wu1, Greg Sun2, Wei Ting Chen1, Yao-Wei Huang1, Hsiang Lin Huang3, Hai Pang Chiang3,4,5 and Din Ping Tsai1,4 1 Department of Physics, National Taiwan University, Taipei 10617, Taiwan. 2 Department of Physics, University of Mas-sachusetts Boston, Boston, Massachusetts 02125, USA. 3 Institute of Optoelectronic Sciences, National Taiwan Ocean University, Keelung 20224, Taiwan. 4 Research Center for Applied Sciences, Academia Sinica, Taipei 11529, Taiwan. 5 Insti-tute of Physics, Academia Sinica, Taipei 11529, Taiwan. *E-mail: [email protected]
Abstract: Split-ring resonators have been the subject of investigation as plasmonic sensors that operate by sensing plasmon resonance shift when exposed to a medium with a refractive index change n, and vertical SRRs are preferable to conventional planar SRRs for greatly enhanced sensitivity.
Introduction The optical properties of the plasmonic metamaterials are often times intrinsically connected to the localized surface plasmon (SP) resonances (LSPR) arising from the collective oscillations of free electrons which induce strong electromagnetic elds adjacent to the artificial sub-wavelength metallic elements in the metamaterials. The resonance wavelengths are determined by feature geometries of metamaterial elements and their surrounding environment, and thus can be tuned by either changing the element dimensions or the surrounding dielectric. Such a property can be explored for a variety of applications, one of which is sensing based on the following general design principle. The motivation of exploring metamaterials for the sensing application is the potential for achieving high sensitivity. To this end, metamaterials require to possess strong plasmon resonance features that are sensitive to environment change. The split-ring resonator (SRR) is such a metal structure that is typically used as a building block for metamaterials because of its strong magnetic resonance accompanied with strong field enhancement within the SRR gap [1]. One important measure of a metamaterial sensor is its sensitivity characterized as the ratio of LSPR shift to the change in refractive index of its nearby sensing medium ( / n). Unfortunately, a majority of the metamaterials reported so far have planar SRRs that lay flat on substrates, resulting in a rather appreciable fraction of the plasmon energy distributed in the dielectric substrate below which limits the effective sensing volume as well as the sensing performance [2]. In this work, we report the fabrication of vertical SRRs (VSRRs) capable of lifting essentially all of the localized fields above the supporting substrate they stand on as illustrated in Fig. 1(a). Using Fourier transform infrared spectroscopy measurement and numerical simulation software, we demonstrate that plasmonic refractive index sensors constructed of VSRRs deliver significantly improved sensitivity over their planar counterparts reported in the literature.This upright configuration strongly confines an electromagnetic field within the gap as the magnetic plasmon is excited, suspending the enhanced field entirely in the free space away from the dielectric substrate and thus increasing the sensing volume. To demonstrate and examine the sensing performance of the VSRR structure, we have performed the sensitivity analysis by experiment and simulation. According to the linear fitting, the simulation has predicted a sensitivity of about / n = 797 nm/RIU, while our measurement has produced a less value of 603 nm/RIU, as shown in Fig. 1(b). It is interesting to point out that our transmittance measurement has yielded spectral resonance shift between the two different liquids greater than what was predicted by the simulation.
Figure 1. (a) Illustration of the field distribution in the VSRR gap and its advantage for increasing sensing volume. (b) The resonance wavelength associated with magnetic resonance of experimental (orange dots) and simulation (purple dots) results as a function of the surrounding refractive index. References [1] P. C. Wu, et al., Nanophotonics 1, 131(2012). [2] A. Dmitriev et al., Nano Letters 8, 3893(2008).
238 P-02-10
Plasmonic Coupling of Gold Curvilinear Nanorodd Dimers at Different Distances
Yukie Yokota1) and Takuo Tanaka 1,2),3) 1) RIKEN Metamaterials Lab., 2-1 Hirosawa, Wako, Saitama, 351-0198, JAPAN 2) RIES, Hokkaido Univ., N21W10, Kita-Ward, Sapporo, Hokkaido, 001-0021, JAPAN 3) Interdisciplinary Graduate School of Science and Engineering, Tokyo Institute of Technology E-mail address: [email protected]
Abstract: We fabricated gold curvilinear nanorod dimers with different gap width. Extinction spectrum of gold curvilinear nanorod has two resonant peaks. Compared to resonant peaks of curvilinear nanorod dimer with different gap width, the peak wavelength of the spectrum is dependence on the gap width.
1. Introduction The local-mode surface plasmon (LSP) resonances of a closely-spaced dimer of two identical metal nanostructures, such as straight nanorods, nanoparticles, strongly interact due to the dipole-dipole coupling. These strong interactions have been exploited in various applications, such as surface-enhanced Raman scattering, biosensing, and near-field optical spectroscopy, and so on. Nevertheless, there are few reports about the spectral properties of LSP on a pair of two complicated shapes nanostructures. We fabricated gold nanostructures that were artificially designed curve geometry using microfabrication techniques. In this work we present detailed studies of plasmonic coupling of gold curvilinear nanorod dimer with controlling gap distance. 2. Experimental results Gold nanostructures were fabricated on the glass substrate using an electron beam lithography and lift-off technique. The thickness of gold nanostructures is fixed at 40 nm. The line widths of the all nanorods are the same as 70 nm. As shown in fig.1, the gap width of curvilinear nanorod dimer of sample (a), (b), (c), (d), (e), and (f) are 5nm, 15nm, 65nm, 130nm, 185nm and 460 nm, respectively. Extinction spectra of the fabricated nanostructures were measured using a commercially available Fourier-transform infrared (FT- Fig. 1. Electron micrographs of fabricated IR) spectrometer equipped with a microscope attachment. gold curvilinear nanorod dimers various gap width (5nm-275nm). 3. Results and discussion Extinction spectra of gold curvilinear nanorod dimers with various gap widths under the unpolarized light illumination are shown in Fig. 2. Extinction spectra of gold nanorod dimers represent two distinct peaks (around 1000 nm and 1500 nm) in the wavelength region. Extinction peak of sample (d) at 1000 nm is originated their peak position is the same as that of the structure of the half of the arc length (l/2) of curvilinear nanorod. Their peak position at 1500nm is the same as that of the structure of the arc length (l) of curvilinear Fig. 2. Extinction spectra of nanorod. Fig. 3 shows polarization dependences of the extinction spectra on the curvilinear nanorod dimers with direction of linearly polarized lights of x (Fig. 3(1)) and y (Fig. 3(2)) directions. various gap width with unpolarized Two resonant peaks of curvilinear nanorod dimers split in Fig. 3 (1) and (2). light illumination. When the linearly polarized light that oscillates y-direction is illuminated, extinction spectra of gold curvilinear nanorod dimer (a) and (c) have one peak at the same wavelength of 3000 nm. The peak of gap width (275nm) was blue shift in the wavelength region. Extinction peak of sample (b) at 2500 nm is originated from vertical plasmon resonance of nanorods. When the polarization direction of the incidence changes x-direction, the extinction spectra of samples (a), (b), and (c) become different as shown in Fig.2 (2). Absorption peak of sample (a)-(b) are appeared at about 1750 nm and their peak position is the same as that of the structure of the half of the arc length (l/2) of sample (a). Compared to resonant peaks of the sample (a) and (b), the extinction spectrum of sample (c) splits to two peaks and its center position is at around 1750 nm.
4. Conclusions Fig. 3. Extinction spectra of gold We fabricated gold curvilinear nanorods with narrow gap. When the nanostructures with various gap width. The directions of linearly linearly polarized light that oscillates x-direction is illuminated, extinction polarized lights are (1) x-, and (2) y- spectrum of gold hybrid nanostructures whose rod length corresponds to the arc directions. The figure shows the length of curvilinear structure splits to two peaks in near-infrared region. layout of dimer and polarization.
239 P-02-11
Excitation of Surface Waves on the Interfaces of General Bi-isotropic Media
Seulong Kim and Kihong Kim Department of Energy Systems Research and Department of Physics, Ajou University, Suwon 16499, Korea E-mail address: [email protected]
Abstract: We study the unique characteristics of the surface waves excited on the interface between a metal (or a dielectric) and a general bi-isotropic medium theoretically, using a generalized version of the invariant imbedding method.
Bi-isotropic media, which include isotropic chiral media and Tellegen media as special cases, are the most general form of linear isotropic media, where the electric displacement D and the magnetic induction B are related to both the electric field E and the magnetic intensity H [1]. In this paper, we study theoretically surface waves excited on the interface between a metal (or a dielectric) and a general bi-isotropic medium. At first, we derive a generalized form of the dispersion relation for surface waves between a semi-infinite dielectric and a semi-infinite bi-isotropic medium analytically. In addition, we develop a generalized version of the invariant imbedding method, which can be used to solve any wave propagation problem in arbitrarily- inhomogeneous stratified bi-isotropic media [2]. Using this method, we calculate the reflectance, the transmittance and the field amplitude inside the medium in a numerically precise manner for various kinds of configurations. We compare the results obtained using the invariant imbedding method with the analytical dispersion relation and confirm that the agreement is perfect. We give a detailed discussion of the unique characteristics of surface waves excited on the interfaces of general bi-isotropic media. As an example, in Fig. 1, we plot the absorptance, which is the fraction of the incident wave energy absorbed into the medium due to the excitation of the surface wave, versus incident angle. Circularly- polarized waves are incident from a dielectric region where ͍=͔=4 onto a bilayer slab made of a chiral medium with ͍=͔=2 and the chiral index ͋=2 and a dielectric medium with ͍=͔=2, and then transmitted to a vacuum region. The thickness of the chiral slab is equal to the vacuum wavelength and that of the dielectric slab is twice the vacuum wavelength. In the present case, the wave impedance is equal to 1 throughout the space. We notice that strong surface waves are excited at ͐=34.7o only when left-circularly- polarized waves are incident. In Fig. 2, we show the electric field distribution at ͐=34.7o. The wave is assumed to be incident from the region where z>1.5d and the plane z=d corresponds to the interface between the chiral slab and the dielectric slab. Some peculiar aspects associated with this type of surface modes are analyzed in detail.
Fig. 1 Fig. 2
[1] I. V. Lindell, A. H. Sihvola, S. A. Tretyakov, and A. J. Viitanen, Electromagnetic Waves in Chiral and Bi- Isotropic Media (Artech House, 1994). [2] S. Kim and K. Kim, unpublished.
240 P-02-12
Anomalous Beam Steering in Vertical Split-Ring Resonator Based Metasurface
Ching-Fu Chen1,*, Wei-Lun Hsu1, Pin Chieh Wu1, Jia-Wern Chen1, Ting-Yu Chen1, Bo Han Cheng2, Wei Ting Chen1, Yao-Wei Huang1, Chun Yen Liao1, Greg Sun3, Din Ping Tsai1,2 1Department of Physics, National Taiwan University, Taipei, Taiwan 2Research Center for Applied Sciences, Academia Sinica, Taipei, Taiwan 3Department of Engineering, University of Massachusetts Boston, Boston, MA, USA *E-mail address: [email protected]
Abstract: Metasurfaces, created artificially with metal nanostructures, have shown the ability of anomalous light manipulation. However, most of the reported works are based on two- dimensional metal structures, owing to nanofabrication difficulties. Recently, we have developed an advanced electron beam lithographic process that brings the deposition of three- dimensional nanostructures into reality. These specific 3D metamolecules, called vertical split-ring resonators (VSRRs), open up another degree of freedom for metasurface design. Here, we numerically demonstrate that phase-modulated anomalous reflection can be achieved by tuning only the vertical dimension of the VSRRs. Fixing the base dimensions of VSRRs, we vary their prong heights to obtain 2 phase modulation. Finite-difference time- domain (FDTD) simulations show that at telecommunication wavelength = 1548 nm, anomalous beam steering of a wide range of angles is accomplished with high extinction ratio. In addition, the footprint of our 3D VSRR-based metasurface is only half of that of other 2D rod-based metasurfaces, enabling high density intergration of metal nanostructures. Design, method, and results We have recently developed a high precision alignment technique that enables us to fabricate metasurfaces made of the vertical split-ring resonators (VSRRs)[1–3] capable of both phase and reflection modulation by controlling the VSRR dimensions. In comparison with 2D SRRs where the tunings of LSPRs are achieved with variation of dimensions in the x-y plane of the metasurface, the VSRRS allows for phase and reflectance modulation by changing the heights of their prongs along z-direction, effectively providing an additional degree of freedom in design. Here we propose to use VSRRs as the basic building blocks to construct metasurface that reflects a normal incident light within telecommunication band to a direction tunable by design in violation of the conventional Snell’s law. The metasurface is patterned with periodical unit cells where each unit consisting of six Au VSRRs with gradient prong lengths sitting on fixed base. The unit cell period determines the reflection angle of light upon its incidence on the metasurface. This investigation is carried out with numerical simulation where we have used the periodical boundary conditions. Results indicate that a highly directional reflection can be achieved with the full-width-at-half-maximum (FWHM) angle of 2.9o at = 1548 nm and the anomalous reflection signal shows the extinction ration as high as 31 relative to that of normal reflection. In comparison with the metasurface made of 2D metal nano-rods where the LSPR is modulated with rod length, our 3D-VSRR design with tuning of prong height has the advantage of covering the surface area with higher density of metal structures which is desirable for minimizing metasurface device size for applications in integrated photonics [4]. References [1] W. T. Chen, C. J. Chen, P. C. Wu, S. Sun, L. Zhou, G.-Y. Guo, C. T. Hsiao, K.-Y. Yang, N. I. Zheludev, and D. P. Tsai, "Optical magnetic response in three-dimensional metamaterial of upright plasmonic meta- molecules," Opt. Express 19, 12837-12842 (2011). [2] P. C. Wu, W. T. Chen, K.-Y. Yang, C. T. Hsiao, G. Sun, A. Q. Liu, N. I. Zheludev, and D. P. Tsai, "Magnetic plasmon induced transparency in three-dimensional metamolecules," Nanophotonics 1, 131– 138 (2012). [3] P. C. Wu, G. Sun, W. T. Chen, K.-Y. Yang, Y.-W. Huang, Y.-H. Chen, H. L. Huang, W.-L. Hsu, H. P. Chiang, and D. P. Tsai, "Vertical split-ring resonator based nanoplasmonic sensor," Appl. Phys. Lett. 105, 033105 (2014). [4] W.-L. Hsu, P. C. Wu, J.-W. Chen, T.-Y. Chen, B. H. Cheng, W. T. Chen, Y.-W. Huang, C. Y. Liao, G. Sun, and D. P. Tsai, "Vertical split-ring resonator based anomalous beam steering with high extinction ratio," Sci. Rep. 5, 11226 (2015).
241 P-02-13
ManipulatingM polarization and light propagation based on subwavelength structures
Jinhui Shi*, Hong Liu, Wenjin Lv, Shenying Fang, Yuxiang Li, Zheng Zhu, Chunying Guan Key Laboratory of In-Fiber Integrated Optics of Ministry of Education, College of Science, Harbin Engineering University E-mail address: [email protected]
Abstract: The field of metamaterials has been developing rapidly in recent years. We will present experimental results of manipulating polarization properties using chiral metamaterials. In addition, we demonstrated that in slabs of linear material of sub-wavelength thickness optical manifestations of birefringence and optical activity can be controlled in the coherent technique.
Metamaterials have received much attention in recent years [1]. Metamaterials with subwavelength elements can control properties of electromagnetic wave to realize desirable amplitude, phase-shift or polarization conversion in unconventional way that can be unachievable using traditional materials. For instance, chiral metamaterials and metasurfaces, as promising candidates, hold great advantages and flexibilities to manipulate the polarization state. Substantial efforts have been devoted to the exploration of gradient metasurfaces, leading to the demonstration of wave-front shaping, photonic spin Hall effect, optical vortex plate, broadband optical retardation, propagating-to-surface-wave conversion, flat lenses and mirrors, super-oscillatory focusing and optical holograms. We will present experimental results of manipulating polarization properties using chiral metamaterials. We demonstrated that in slabs of linear material of sub-wavelength thickness optical manifestations of birefringence and optical activity can be controlled in the coherent technique. In addition, reflection and refraction effects on phase gradient metasurfaces can be coherently controlled shown in Fig.1. Such control can be exerted at arbitrarily low intensities, thus arguably allowing for fast handling of electromagnetic signals without facing thermal management and energy challenges. 200 120 S (b) S (c) xx (a) Control beam S Signal output S1 150 yx x-polarized 80 S1 S2 Fit Normal beam -j E e 100 Anomalous beam x-to-x 0 Fit x-to-y 40
intensity (%) 50 Output (%) intensity Output & absorption Output & ( =635nm A 0 0 0 90 180 270 360 0 90 180 270 360 d Phase difference (Degree) Phase difference (Degree) y (d) Anomalous Ey under x-polarized illumination z = 0 = 90 = 270e +max x e e = 180e k t Control %t Anomalous beam ) y
x-to-y Normal beam E E0 x-to-x
Signal beam Re( Control output S2 x-polarized z Signal
-min x Fig. 1. Coherent control of the gradient metasurface of V-shaped slot antennas for a wavelength of 635nm.
References [1] N. I. Zheludev, Science 348(6238), 973 (2015). [2] J. H. Shi, H. F. Ma, C. Y. Guan, Z. P. Wang, and T. J. Cui, Broadband chirality and asymmetric transmission in ultrathin 90°-twisted Babinet-inverted metasurfaces, Phys. Rev. B 89, 165128 (2014). [3] S. A. Mousavi, E.Plum, J. H. Shi, and N. I. Zheludev, Coherent control of optical polarization effects in metamaterials, Sci. Rep. 5, 8977 (2015). [4] J. H. Shi, X. Fang, E. T. F. Rogers, E. Plum, K. F. MacDonald, and N. I. Zheludev, Coherent control of Snell’s law at metasurfaces, Opt. Express 22, 21051-21060 (2014) . [5] C. Y. Guan, M. Ding, J. H. Shi, P. Hua, P. F. Wang, L. B. Yuan, and G. Brambilla, Experimental observation and analysis of all-fiber plasmonic double Airy beams, Opt. Express 22 (15), 18365-18371 (2014). [6] J. H. Shi, R. Liu, B. Na, Y. Q. Xu, Z. Zhu, Y. K. Wang, H. F. Ma, and T. J. Cui, Engineering electromagnetic responses of bilayered metamaterials based on Fano resonances, Appl. Phys. Lett. 103, 071906 (2013). [7] J. H. Shi, X. C. Liu, S. W. Yu, T. T. Lv, Z. Zhu, H. F. Ma and T. J. Cui. Dual-band asymmetric transmission of linear polarization in bilayered chiral metamaterial. Appl. Phys. Lett. 102, 191905 (2013).
242 P-02-14
Enhancement Effect of Gold Substrate on the Whispering-i Gallery Modes of Fluorescent Conjugated Polymer Microspheres
Jhih-Yuan Chen 1, Fan-Cheng Lin1, Soh Kushida2, Yohei Yamamoto2 and Jer-Shing Huang1,* National Tsing Hua University1, University of Tsukuba2 E-mail address: (JYC) [email protected] & (JSH) [email protected]
Abstract: We study the influence of plasmonic gold film substrate on the whispering-gallery modes (WGM) of fluorescent conjugated polymer microspheres. Different WGMs can be selectively excited by controlling the excitation position of the laser focus on the sphere. We compare the spectra of the spheres taken with and without gold film and found that two kinds of WGMs (TE and TM modes) along the meridian have been differently enhanced, suggesting the symmetry-dependent effect from the surface plasmons on the gold film. Numerical simulations have been performed to understand the mechanism of the enhancement.
243 P-02-15
Metal Enhanced Fluorescence of Silver Hybrid Nanostructures
Jiunn-Woei Liaw1, 2, Meng-Han Fang3, Yu-Hsiang Huang3, Kai-Hong Tsai3, Chieh-Jen Lin3, and Hai- Pang Chiang3, 4* 1Department of Mechanical Engineering, Chang Gung University, 259 Wen-Hwa 1st Rd., Kwei-Shan, Taoyuan 333, Taiwan 2Center for Biomedical Engineering, Chang Gung University, 259 Wen-Hwa 1st Rd., Kwei-Shan, Taoyuan 333, Taiwan 3Institute of Optoelectronic Sciences, National Taiwan Ocean University, Keelung, Taiwan 4Institute of Physics, Academia Sinica, Taipei, Taiwan E-mail address: [email protected]
Abstract: A silver hybrid nanostructure was proposed for metal enhanced fluorescence (MEF). We combined silver 2D periodic array with silver nanoparticles to form multiscale structures. The photoluminescence (PL) and time-resolved photoluminescence (TRPL) of DCJTB on the hybrid nanostructures were characterized to show the potential for the application of MEF.
Introduction The nanosphere lithography (NSL) has been widely used for the fabrication of metallic 2D hexagonally periodic nanotriangle array [1-2]. The nanostructures have been applied on the fields of surface enhanced Raman scattering (SERS) [3] and metal enhanced fluorescence (MEF) [4]. In this paper, a new hybrid nanostructure is proposed, consisting of silver submicron periodic array and silver nanoparticles (NPs). The MEF effect of this hybrid nanostructure on the fluorescence of DCJTB is characterized by the photoluminescence (PL) and time- resolved photoluminescence (TRPL) measurements. We used NSL to fabricate 2D periodic array with 400-nm sized polystyrene spheres. Subsequently, we coated a silver colloid, an aqueous solution of silver NPs with size of 30 to 55 nm, on the 2D periodic array to fill each element. As a result, a substrate with silver hybrid nanostructures was produced, in which a submicron- scaled structure is associated with nanoparticles. After that, the silver hybrid nanostructures were covered and protected by an ultrathin layer of SiO2 film as a buffer layer, and then a layer of DCJTB (4-(dicyanomethylene)- 2-t-butyl-6-(1, 1, 7, 7-tetramethyljulolidyl-9-enyl)-4Hpyran) was deposited on the SiO2 layer as the luminescent material. The PL and TRPL of three kinds of substrates were measured to characterize their MEF performance on DCJTB; one is a glass, another a glass with silver triangular nanotips array alone, and the other a glass with silver hybrid nanostructures. The light sources for PL and TRPL measurements are the CW and pulsed (pulse- width 55 ps) modes of a 375-nm diode laser [4]. Figure 1 shows the PLs on three different substrates: a glass, a glass with silver triangular nanotips array alone, and a glass with silver hybrid nanostructures. The results indicate that the PL of DCJTB is significantly enhanced by the silver hybrid nanostructures.
Fig. 1 References [1] P. Colson, C. Henrist, and R. Cloots, J. Nanomaterials 2013, 948510, 2013. [2] M. Tabatabaei, A. Sangar, N. Kazemi-Zanjani, P. Torchio, A. Merlen, and F. Lagugné-Labarthet, J. Phys. Chem. C 117, pp. 14778, 2013. [3] S. Mühlig, D. Cialla, A. Cunningham, A. März, K. Weber, T. Bürgi, F. Lederer, and C. Rockstuhl, J. Phys. Chem. C 118, pp. 10230 1023, 2014. [4] H.-L. Huang, C. F. Chou, S. H. Shiao, Y.-C. Liu, J.-J. Huang, S. U. Jen, and H.-P. Chiang. Opt. Express 21(S5), pp. A901-A908, 2013.
244 P-02-16
A novel fabrication technique for an efficient surface enhanced Raman scattering substrate using nanosphere lithography
Kai-Chieh Hsu1, Y. -C. Liu1, Yu-Hsiang Huang1, Kai-Hong Tsai1, Chieh-Jen Lin1, P. T. Leung2, and Hai-Pang Chiang1, 3* 1 Institute of Optoelectronic Sciences, National Taiwan Ocean University, Keelung, Taiwan 2 Department of Physics, Portland State University, P. O. Box 751, Portland, OR 97207-0751, U. S. A. 3Institute of Physics, Academia Sinica, Taipei, Taiwan E-mail address: [email protected]
Abstract: We present a novel technique for the fabrication of surface enhanced Raman scattering (SERS) substrates with high enhancement ratio based on nanosphere lithography (NSL) on Polydimethylsilozane with lift-off. An enhancement ratio of 6.5 x 106 can be reached which surpasses the performance of all the other SERS substrates we reported previously using NSL.
Introduction Since the discovery in 1974 by Fleishman and coworkers, SERS has been recognized as a powerful technique for molecular identification and has found significant applications in the probing of biomolecules. One interesting example in the last area is the fabrication of flower-like nano architectures which enable the detection of R6G molecules down to a concentration of 10-12 M [1]. Nanosphere lithography (NSL) is a powerful technique for the fabrication of large area of monolayers with periodic array structures. This technique is versatile for its low-cost and simple protocol, as well as its flexibility in the control of the periodicity (by simply using spheres of different sizes), leading to the desired optical absorption bandwidth in certain specific applications such as in the preparation of SERS substrates [2, 3]. In this work, we employ Convection Self-Assembled (CSA) technique to fabricate periodic array of silver nanostructures on Polydimethylsilozane (PDMS) substrates instead of glass substrates that were used previously [2, 3]. We shall see that with an additional lift-off process, cracked structures with large gaps of widths 10 – 50 nm can be formed which can lead to huge enhancements when used as a SERS substrate for light scattering from R6G molecules. Figure 1 shows the SEM images of various SERS substrates fabricated via the NSL technique described above, using polystyrene sphere of different sizes with diameters 1500 nm, 1000 nm, 820 nm, and 740 nm, respectively. It is observed fragmented triangular silver structures were created on the PDMS substrate from the lift-off process with a “nano hole” appearing at the center of these triangles, with these holes becoming larger when smaller polystyrene spheres were being used. Figure 2 shows the SERS spectra from the five different substrates from which the peak intensity at a wave number of 1365 cm-1 for the R6G molecule is compared. We have confirmed the present optimum enhancement of 6.5 x 106 does surpass all those optimum values obtained in our previous experiments [2, 3].
Fig. 1. Fig. 2 References [1] G. Duan, W. Cai, Y. Luo, Z. Li, and Y. Li, Appl. Phys. Lett. 89, 211905(1)-211905(3), 2006. [2] W. C. Lin, S. H. Huang, C. L. Chen, C. C. Chen, D. P. Tsai, H. P. Chiang, Applied Physics A. 101(1), 185–189, 2010. [3] W. C. Lin, L. S. Liao, Y. H. Chen, H. C. Chang, D. P. Tsai, and H. P. Chiang, Plasmonics 6(2), 201–206, 2011.
245 P-02-17
NarrowN band metasurface based on gap-plasmon in lossy cavity
Chih-Ming Wang1,*, Wei-Yi Tsai2, Ching-Fu Chen2, Ting-Yu Chen2, Din Ping Tsai2,3 1Institute of Opto-electronic Engineering, National Dong Hwa University, Hualien 97401, Taiwan 2Department of Physics, National Taiwan University, Taipei 10617, Taiwan 3Research Center for Applied Sciences, Academia Sinica, Taipei 115, Taiwan E-mail address: [email protected]
Abstract: Usually, people say that the unique electromagnetic response of metamaterials as well as metasurfaces is from the arbitrarily designed structure but not from its base materials. In this paper, we demonstrate a magnetically resonant metasurface with a high quality factor combining both designed structured resonance and inherent property of the based materials. By using this unique design rule, a high Q-factor metasurface with low angle-dependent has been demonstrated. The proposed structure will be useful for high sensitivity sensing and narrow band thermal emitter.
1. Introduction to main text format and page layout Metamaterials, with desirable and designable bulk electromagnetic behavior, are typically engineered by arranging a set of arbitrary designed structures in a regular array throughout a region of space. Achieving narrow resonance by using metamaterials as well as metasurfaces is an area of interest for both fundamental research and practical applications such as high sensitive detection and narrowband filter. Especially the widely investigated split ring resonator (SRR) based designs show a strong angular dependence, as the transmission properties of these structures rely in part on a coupling with a surface electromagnetic wave. Moreover, this kind of structure is usually with low quality factors (Q-factor) due to the symmetry and inherent loss of utilized material.
o =20 in 50 4.0 8 Resonace wavelength WAg=3.5 m Q-value 3.5 m) 40 7 3.0 30 2.5 Q 6 - value
2.0 20 5 1.5 Reflectance (a.u.) WAg=1.5m 10
1.0 Resonance wavelength ( 4
0.5 0 4681012 1.0 1.5 2.0 2.5 3.0 3.5 Wavelength(m) W (m) Ag
o Fig. (a) Absorption spectrum of 1D metasurfaces with a series of WAg. The incident angles are at in=20 . (b) Q-factors and resonance wavelengths of the fundamental FP modes as a function of width of metallic wires.
In this paper, we demonstrate a new method to improve the Q-factor of metasurfaces. The structure is a SiO2 layer sandwiched by 1D Ag wire array and Ag thin film. Fig. 1(a) show the reflectance spectrum of the o investigated structures at an incident angle of 20 .The thickness of the SiO2 layer and period of Ag wire is kept to be 100nm and 5mm, respectively. For reference, the black line shows in the FTIR absorption spectrum of a silicon substrate sequentially coated with 100nm Ag and 100nm SiO2. It is shown a weak absorption peak at 8.1 m which is due to the inherent absorption of SiO2. The red, orange, yellow, green and blue solid lines represent the reflection spectrum for Ag wire width WAg=1.5m, 2.0m, 2.5m, 3.0m and 3.5m, respectively. The Q- values and the resonance wavelengths of the fundamental FP modes of the gap-plasmon resonances are shown in Fig.1 (b). It is shown that the resonance wavelength can be increased as an increasing width of Ag wires. As the gap-plasmon resonance is close to the inherent absorption of SiO2, the near-field coupling at the two metallic layers is inefficient due to the absorption. At this time, the band tail of the gap-plasmon resonance is suppressed as it is close to the absorption wavelength of SiO2. Therefore, thanks to the inherent absorption of the dielectric layer, we can enhance the Q-value of metasurfaces by a factor up to 4-fold.
[1] M. Rahmani, B. Lukiyanchuk, T. Tahmasebi, Y. Lin, T. Liew, and M. Hong, Appl. Phys. A Mater. Sci. Process. 107, 23-30 (2012). [2] Author(s), "Title of paper," in Title of Proceeding, (Institute of Electrical and Electronics Engineers, New York, 1900), pp. 00-00. [3] Author(s), "Title of paper," in Title of Proceedings, Name(s), ed(s)., Vol. XX of OSA Proceedings Series (Optical Society of America, Washington, D.C., 1900), pp. 00-00.
246 P-02-19
Plasmonic resonance of Ge2Sb2Te5 nanoantenna for metasurface
Hsiang-Chu Wang1, Cheng Hung Chu2, Ming Lun Tseng1, and Din Ping Tsai1, 2 1 Department of Physics, National Taiwan University, Taipei 10617, Taiwan. 2 Research Center for Applied Sciences, Academia Sinica, Taipei 11529, Taiwan. E-mail: [email protected]
Abstract: We present the initiative optical resonance of phase change material Ge2Sb2Te5 in the near-infrared regime. Further, we introduce the concept of reconfigurable gradient metasurface, which has different anomalous reflection angles by the combination of unit cells with different geometries and phase states. The research has great potential in the area of the metamaterial device (metadevice).
247 P-02-20
Efficient polarization-controlled Meta-hologram
Yi-Hao Chen1, Wei Ting Chen1, Kuang-Yu Yang2, Chih-Ming Wang3, Yao-Wei Huang1, Greg Sun4, Shulin Sun5, Lei Zhou6, Ai Qun Liu7, Din Ping Tsai1,2 1Department of Physics, National Taiwan University, Taipei 10617, Taiwan; 2 Research Center for Applied Sciences, Academia Sinica, Taipei 115, Taiwan; 3 Institute of Opto-electronic Engineering, National Dong Hwa University, Hualien 97401, Taiwan; 4 Department of Physics, University of Massachusetts Boston, Boston, Massachusetts 02125, USA; 5 Department of Optical Science and Engineering, Fudan University, Shanghai 200433, China; 6 State Key Laboratory of Surface Physics and Key Laboratory of Micro and Nano Photonic Structures (Ministryof Education), Fudan University, Shanghai 200433, China; 7 School of Electrical and Electronic Engineering, Nanyang Technological University, Singapore 639798, Singapore E-mail address: [email protected]
Abstract: We demonstrate a highly efficient reflective meta-hologram made of gold cross nanoantennas which can reconstruct polarization-controlled dual images with the modulation of the phase. It works well under both the incoherent and coherent light sources with a broad spectral range.
Holography is a method of recording complete information about the light and then reconstruct the corresponding images. Although widely used but with limited applications because of the constituent materials and the narrow working range of the electromagnetic region [1]. Recently, plasmonic metamaterials have attracted a lot of attention, which exhibit dramatic amplitude and phase modulation. Here we report a high-efficiency and broadband meta-hologram made from plasmonic metamaterials, as shown in Fig. 1(left).
Fig. 1:ġ(left) Our designed meta-hologram under VW5 linearly polarized light.ġ (Right) Reconstructed images under (a) x-polarized (b) VW5-polarized, and (c) y-polarized incidence by a 780 nm laser. Ones under (d) 700Ə20 nm , (e) 600Ə20 nm and (f) 550Ə20 nm using a broadband incoherent light source and bandpass filters.
With the computer-generated holography, we calculate the required phase distributions that would respectively produce “NTU” and “RCAS” images under x- and y-polarized light of wavelength 780 nm. It’s then fabricated with a gold mirror coupled with 50-nm-thick gold cross nanoantennas and a 50-nm-thick 5 MgF2 spacer. Four selected rod lengths (60, 105, 125 and 209 nm) correspond to the [R -separated reflection phase to design a 4-level phase plasmonic meta-hologram. A 780-nm diode laser as well as a white light source is used to reconstruct the images. Figure 1(right, a-c) show polarization-controlled reconstructed images under different linearly polarized laser illuminations. The projected patterns are selectively produced as “NTU” for x-polarization and “RCAS” for y-polarization. For both x- and y-polarized incidence, the ̓ measured polarization contrasts ( Ơ̓ , I: intensity) are ~20, which confirms the polarization selectivity. Ά烒烐烢 ͊ The efficiency ( Ɵ ,P: power), was also recorded as ~18%. Figure 1(right, d-f) show the images from ͊Άͷ͵·ġ different wavelengths of an incoherent light source. Every reconstructed NTU pattern can be clearly observed under x-polarized incidence, which confirms that our meta-hologram has a broadband working ability. In conclusion, we’ve demonstrated a highly efficient reflective meta-hologram, utilizing phase modulation at plasmonic resonance of gold cross-nanoantennas to record two polarization-controlled images. By combining with techniques of tunable metamaterials [2], it can potentially be used to realize active holograms that work at arbitrary frequencies. References [1] M. Ozaki et al., Science 332, 218-220 (2011) [2] J.-Y. Ou et al., NAT. NANOTECHNOL. 8, 252-255 (2013)
248 P-02-21
Lifetime Modification of Fluorescence Decays By DNA-NA linked Gold Nanoparticles
Chun-Chou Lin1, Pei-Xuan Lan2, Chung-Kai Lin2, Ya-Lan Feng3, Yeh Lin2, Yi-Chun Chen2* 1Institute of Light and Energy Photonics, National Chiao Tung University, Tainan, Taiwan 2Institute of Imaging and Biomedical Photonics, National Chiao Tung University, Tainan, Taiwan 3Institute of Photonic System, National Chiao Tung University, Tainan, Taiwan *E-mail address:[email protected]
Abstract: Plasmon-controlled fluorescence lifetime and intensity were investigated with designs of DNA-linked gold nanoparticle assemblies. Compared with top-down nanofabrication methods, SPR devices assembled by DNA have the advantage of exact control on molecule labelling position onto surface plasmon resonance (SPR) hot spots. Here, we applied DNAs as the linker to design the distance between the gold nanoparticle and fluorophore. By changingġ the length of DNA, we found thatġ fluorescence lifetime becomes shorter as the distance between SPR hot spot and the dye is closer. Exact control of fluorescence lifetime and intensity become possible for novel SPR biosensor design.
In this study, we employed DNA-directed self-assembled gold nanoparticle (AuNP) structures [1, 2] to construct localized surface plasmon resonance (SPR) biosensor. With different designs of DNA origami, the bottom-up approach for SPR devices demonstrates several advantages, e.g. exact control of biomolecule position relative to the metal surface as well as in the SPR hot spots. Therefore, we analyzed fluorescent lifetime and fluorescence intensity of dyes labelled on the AuNP devices, and calculated both radiative and non-radiative pathways of the SPR-controlled fluorescence signals [3, 4]. The quantitative information on interactions between SPR and fluorephores can help to design novel SPR biosensors. We first applied two sizes of the AuNPs, 10 nm and 20 nm in diameter respectively, and added fluorescence dye solution with different concentration. Then, fluorescence lifetime and intensity of the sample were acquired. We compared the results with experiment of well-controlled distance between fluorephores and AuNPs. We attached DNA linkers onto AuNPs; the DNA linkers had fluorescence dyes modification at the other end (as shown in Fig. 1.). While there is strong localized field induced by SPR, it was also observed that fluorescence lifetime becomes shorter as fluorophore gets closer to the AuNPs. The stronger the electric field is, the shorter the lifetime is. Based on this characterization, we were able to control the lifetime of the fluorophore by modifying DNA linkers to determine the distance between AuNPs and fluorophores. Exact control of fluorescence lifetime and intensity by SPR will be possible, using SPR devices built by DNA- AuNPs composite.
Fig. 1. Application of DNA linker with different length to control the distance between AuNPs and florescence dyes.
References [1] G. P. Acuna, F. M. Möller, P. Holzmeister, S. Beater, B. Lalkens, and P. Tinnefeld, "Fluorescence Enhancement at Docking Sites of DNA-Directed Self-Assembled Nanoantennas," Science, 338, 6106, 506-510 (2012). [2] S. Y. Park, A. K. R. Lytton-Jean, B. Lee, S. Weigand, G. C. Schatz, and C. A. Mirkin1, "DNA- programmable nanoparticle crystallization," Nature, 451, 553-556 (2008). [3] A. W. Schell, P. Engel, J. F. M. Werra, C. Wolff, K. Busch, and O. Benson, "Scanning Single Quantum Emitter Fluorescence Lifetime Imaging: Quantitative Analysis of the Local Density of Photonic States," Nano Lett., 14 (5), 2623–2627 (2014). [4] M. R. Gartia, J. P. Eichorst, R. M. Clegg, and G. L. Liu, "Lifetime imaging of radiative and non-radiative fluorescence decays on nanoplasmonic surface," Appl. Phys. Lett., 101, 023118 (2012).
249 P-02-22
Three-dimensionalTh Chiral Metamaterial fabricated using Nanospherical-Lens Lithography
Jyun-De Wu1, Chang-Han Wang2, Yang-Fang Chen1,2, and Yun-Chorng Chang*1,2 1Department of Physics, National Taiwan University, Taipei, Taiwan ijResearch Center for Applied Sciences, Academia Sinica, Taipei, Taiwan E-mail address: [email protected]
Abstract: In this study, we demonstrate an economic nanofabrication method that can be used to fabricate three-dimensional (3D) chiral metamaterials that cover a large area. Nanospherical-Lens Lithography is firstly employed to fabricate periodic metal nanohole arrays on top of photoresist thin film. Following the concept of Hole-mask lithography, the subsequently deposited metal or dielectric materials are evaporated through these subwavelength holes on to the substrate in a controlled manor. 3D chiral metamaterials can be designed and fabricated using the proposed method. Optical properties of these fabricated metamaterials are investigated theoretically and experimentally. Possible applications will also be proposed.
250 P-02-23
Plasmonic Near-field Polarization Analyzer based on Localized Surface Plasmon
Chen-Ta Ku,† Chen-Bin Huang,‡ Yun-Chorng Chang*,† †1 Research Center for Applied Sciences, Academia Sinica, Taipei 11529, Taiwan ‡Institute of Photonics Technologies, National Tsing Hua University, Hsinchu 30013, Taiwan E-mail address: [email protected]
Abstract: In this study, we demonstrate theoretically that a designed cluster of seven nanodisks can be applied to distinguish the polarization and handedness of the incident light. The center nanodisk of the designed cluster is used to receive various linearly, circularly, and elliptically polarized point sources. The surrounding six nanodisks would then form four gaps and the electric field intensities of these gaps can be sued to determine the polarization and handedness states of the incident light. The effects on the shapes, sizes and gap distance of the nanodisk are carefully investigated through electromagnetic simulation. The best possible design for such nanodisk cluster analyzer will be proposed.
251 P-02-24
ElectricalEl t and Optical Performances of Plasmonic Silicon Solar Cells Based on Plasmonics Modulation of Silver and Indium Nanoparticles
Wei-Lien Wang, Wen-Jeng Ho*, Ta-Wei Chuang, Chia-Hua Hu, Yi-Yu Lee Department of Electro-Optical Engineering, National Taipei University of Technology, No. 1, Sec. 3, Zhongxial E. Rd., Taipei (10608), Taiwan, R.O.C. *E-mail address: [email protected]
Abstract: We demonstrate the plasmonic silicon (Si) solar cells with a matrix comprising the patterns of silver nanoparticles (Ag-NPs) indium nanoparticles (In-NPs). We examined the plasmonic scattering modulation of Ag-NPs by using In-NPs. The Raman scattering of Ag- NPs and In-NPs was firstly characterized. We then measured the optical reflectance and external quantum efficiency (EQE) response. We achieved impressive results with regard to plasmonic scattering. The resulted in a 9.93% increase in short-circuit current density (Jsc) (from 31.91 mA/cm2 to 35.08 mA/cm2) and a 10.12% increase in conversion efficiency ( ) (from 13.04% to 14.36%), compared to cells with uniformly distributed Ag-NPs. 1. Introduction Plasmonic effects have recently been applied to the problem of light trapping in silicon solar cells. Metallic nanoparticles (NPs) exhibiting localized surface plasmon (LSP) effects have been used to enhance light absorption in solar cells [1]. An array of Ag and Au nanoparticles on a crystalline silicon solar cell was shown to improve the photovoltaic current-voltage (I-V) characteristics at wavelengths of 800 to 1050 nm via surface plasmon resonance [2]. In this study, we developed novel plasmonic silicon (Si) solar cells with a matrix comprising a pattern of Ag-NPs surrounded by In-NPs. This is the first study to experimentally demonstrate plasmonic-modulated light scattering in silicon solar cells through the application of an Ag-NP/In-NP matrix with various degrees of various coverage. We examined the surface plasmon Raman scattering induced by Ag-NPs and In-NPs. We also compared various matrix configurations with regard to optical reflectance and the external quantum efficiency (EQE) response in solar cells. Finally, we compared the photovoltaic performance of cells with uniformly distributed Ag-NPs, uniformly distributed In-NPs, and Ag-NP/In-NP matrices with various degrees of coverage. The Ag-NPs presented two peaks in the Raman signal intensity (at 1368 and 1600 cm-1) and the In-NPs presented three peaks (at 566, 807, and 1115 cm-1). This may be explained by the strong local field of surface plasmon-resonance (LSPR) produced by Ag-NPs and In-NPs. The optical reflectance of the cell with a matrix-pattern of Ag-NPs/In-NPs was far lower than that of the cell with matrix of Ag-NPs. In the cell with matrix of Ag-NPs/In-NPs, we also observed a decrease in reflectance following a decrease in Ag-NP coverage, particular at wavelengths of 350-550 nm. This demonstrates that the optical reflectance of cells can be modulated by altering the coverage of Ag-NPs and In- NPs on the surface of the cells (as shown in Fig. 1). We observed a broadband increase in EQE values in cells with an Ag-NPs/In-NPs matrix, exceeding that of cells with uniformly distributed Ag-NPs and cells with a Ag-NP matrix. This can be attributed to the combined effects of plasmonic light scattering, induced by In-NPs at wavelengths of 350-650 nm and by Ag-NPs at wavelengths beyond 650 nm (as shown in Fig. 2). The 2 2 resulted in a 9.93% increase in short-circuit current density (Jsc) (from 31.91 mA/cm to 35.08 mA/cm ) and a 10.12% increase in conversion efficiency ( ) (from 13.04% to 14.36%), compared to cells with uniformly distributed Ag-NPs. 2. References [1] J.R. Cole, N. Halas, Appl. Phys. Lett., 89, 153120-1ˉ153120-3(2006) [2] D. Schaadt, B. Feng, E. Yu, Appl. Phys. Lett., 86, 063106-1ˉ063106-3 (2005)
Fig. 1 Optical reflectance Fig. 2 External quantum efficiency (EQE) response
252 P-02-25
Plasmonics-enhanced Metal-Dielectrics-Metal Nano- emitter fabricated using Nanospherical-Lens Lithography
Chi-Ching Liu, Chang-Han Wang, Yun-Chorng Chang* Research Center for Applied Sciences, Academia Sinica, Taipei 11529, Taiwan. [email protected]
Abstract: Plasmonics hybridization has been observed in periodic metal-insulator-metal (MIM) nanodisk arrays fabricated using Nanospherical-Lens Lithography. The bonding mode of the hybridization corresponds to the dark plasmon mode and is dominated by light absorption. The anti-bonding mode of the hybridization corresponds to the bright plasmon mode. In this study, we will insert gain materials in between the two metal nanodisk and investigate the fluorescent properties from this metal-dielectrics-metal system. The properties of the plasmonics hybridization will be fine tuned by varying the size, shape and periodicity of the nanostructures. These results would be useful for future applications in designing new nanoscale lasers.
253 P-02-26
OpticalO properties of anti-symmetric Mach- Zehnder interferometer in a slab plasmonic waveguide
Shun kamada, Toshihiro Okamoto and Masanobu Haraguchi Optical systems Engineering Department, Tokushima University, 2-1 Minamijosanjima, Tokushima city, Tokushima 770-8506 Japan, [email protected]
Abstract: An anti-symmetric Mach-Zehnder (MZ) interferometer in a Metal-Dielectric- Metal slab plasmonic waveguide was proposed for a component of optical circuits. The proposed structure can be fabricated by Electron beam lithography process. The light intensities at output ports were observed in order to confirm the performance of the MZ interferometer. We found that the characteristics of the MZ interferometer agreed with those simulated numerically.
1. Introduction We have been studied about plasmonic integrated circuits base on Metal-Dielectric-Metal slab plasmonic waveguides (PWG). Mach-Zehnder (MZ) interferometers is a key device for a component of integrated circuits. In this study, a layered anti-symmetric MZ interferometer in a slab PWG was proposed. Such the layered anti-symmetric structures allow us to compose highly integrated circuits. The purpose of this study is to confirm the interference in the proposed structure. 2. Experimental Figure 1 shows a SEM image of a cross section of the fabricated anti-symmetric MZ interferometer. Ag thin films and PSSNa (Sodium p-styrenesulfonate Homo-Polymer) films were formed on a Si substrate by vacuum evaporation and spin coating, respectively. The patterns were fabricated by the electron beam lithography process. The fabrication structure was cut by focused ion beam milling to obtain a cross section. The thickness of the PSSNa film before and after a branch is 130nm and 350nm, respectively. The plasmons can be propagating within those thicknesses PSSNa with Ag cladding. The incident light with TM polarization which has Ez component is illuminated in an input port for excited the plasmons. The plasmons are divided into path 1 and path 2. Both of these experience different optical paths for each other. The incident light of a laser varying wavelength from 1150nm to 1550nm was focused on an input port in the fabricated MZ interferometer. The light intensities at an output port were observed by a CCD camera. Figure 2 shows the spectrum of the scattered light intensities at the output port of the MZ interferometer. The light intensities at the output port were normalized by the reflected light intensities at the plane surface of the Ag film. As a result, by increasing of input wavelength, the light intensities at the output port were decrease. The spectrum shape is qualitatively explained by the result of the numerical simulation considering the interference effect due to the difference of optical path length. 3. Conclusion The proposed anti-symmetric MZ interferometer is fabricated by the electron beam lithography process. We found that the proposed MZ interferometer is performed as an interferometer.
1.5 z
y 1 x Ag Path1 Path2 PSSNa 0.5
350nm 130nm Si substrate in output port(a.u.) Normalized light intensity light Normalized 0 1 m 1100 1200 1300 1400 1500 1600 WavelengthWavelength of incident (nm) light (nm) 0 0 Fig.1 A SEM image of the fabricated Mach-Zehnder Fig.2 Normalized light intensities at an output port interferometer. of the fabricated Mach-Zehnder interferometer.
254 P-02-27
Heterogeneous three-dimensional assembly of metamaterials and metadevices by modular transfer printing
Seungwoo Lee*, Byungsoo Kang*, Hohyun Keum**, Alaa Alokaily**, Hyun-Sung Park*, Numair Ahmed**, John A. Rogers***, Placid M. Ferreira**, Seok Kim**, and Bumki Min* **** * Department of mechanical engineering, Korea Advanced Institute of Science and Technology(KAIST), Daejon, 305-751, South Korea ** Department of mechanical engineering, University of Illinois, Urbana-Champaign, Illinois, 617185, USA *** Department of materials science and engineering, University of Illinois, Urbana-Champaign, Illinois, 617185, USA **** KI for Optical Science and Technology (KIOST), Korea Advanced Institute of Science and Technology (KAIST), Daejeon, 305-751, South Korea [email protected]
Abstract: Metamaterial with exotic, unnatural functionalities often requires integration of multiple materials and complex 3-D structures. However, most of conventional fabrication suffers from compatibility issues such as damage from high temperature and harsh chemicals. Also, lithography, which is major fabrication tool, has been inherently (semi) 2-D. We propose a versatile transfer printing method based on unique dry adhesion of specially designed viscoelastic stamp to build a heterogeneous, three-dimensional metadevices. Using common fabrication tool, different types of building blocks were built and stacked in complex shapes on various substrates. Optical and electrical measurements of transferred samples justify its usefulness. This method will relieve difficulties building meta, optical, and electrical devices demanding conventionally incompatible set of materials and fore- mentioned geometries.
The building of metadevices synergistically benefitting from hybridization of metamaterials and active functional materials has shown great potential for photonic devices. Nevertheless, the level of structural heterogeneity and complexity and the corresponding functions of devices have been limited by restricted fabrication capability. We report three-dimensional (3D) modular stacking with reversible, switchable dry- adhesion. A dry-adhesion with extreme switchability allows integrating broad classes of dissimilar, active materials. Building blocks – single crystal silicon, plasmonic metamaterial, CVD-grown graphene - were fabricated and stacked in more than six layers in plain vertical, under-cut, spiral, and even imbricated shapes on silicon wafer, metal pattern, polyimide film, graphene oxide paper, aluminum foil, and even cheese with arbitrary transverse angles, proving its capabilities on material diversity and spatial complexity. Typical RLC- type resonant curve in an THz-TDS(Time Doman Spectroscopy) measurement result of plasmonic honeycomb metamaterial printed on polyimide shows this method is generally applicable to plasmonic metamaterial. Time-varying signature of same blocks printed on cheese reveals possibility as remote food monitor. Electrical IV characterization results show this method can be used in printable tunable graphene devices. The 3D stacking of modular components allows the construction of more elaborated metamaterials to attain on-demand photonic property. The minimum repetitive process, rapid construction, and reasonable utilization of materials are the additional own advantages attainable with this strategy.
Fig. 1. (a)transfer printing process schematics, SEM(Scanning Electron Microscope) image of the stamp, and optical microscope images of donors (b)a photo of gold-silicon plasmonic metamaterial blocks printed on ink- jet printed paper (c)on graphene oxide paper (d)an optical microscope image of stacked four blocks in a twisted shape on a smooth silicon waferį
255 P-02-28
LocalizedL Surface Plasmon Effect on Fluorescence Lifetime in Photonic Crystals
Dipak Rout1 and R.Vijaya1,2 1Department of Physics, Indian Institute of Technology Kanpur, Kanpur 208016, INDIA 2Centre for Lasers and Photonics, Indian Institute of Technology Kanpur, Kanpur 208016, INDIA [email protected], [email protected]
Abstract: Photonic crystals grown by self-assembly from polystyrene colloids doped with Rhodamine B dye are further infiltrated with gold nanoparticles. Measurements of the stopband features and photoluminescence intensity are supplemented by fluorescence decay time analysis. The influence of localized surface plasmons due to gold nanoparticles on the increase in emission intensity and decrease in decay time of the dye is established.
1. Introduction Photonic crystals (PhCs) are known to be potential candidates for modifying the spontaneous emission characteristics of an emitter embedded inside them [1, 2]. This process can be further manipulated by using appropriate plasmonic materials infiltrated into the crystal [3]. In the present work, we have studied dielectric PhC made of dye-doped polystyrene colloids and metallo-dielectric PhC with infiltrated gold nanoparticles. The angle- dependent stopband characteristics and photoluminescence (PL) studies (intensity and the fluorescence decay time) from the PhC and gold-infiltrated PhC (GIPhC) enable the effect of localized surface plasmon resonance (LSPR) on the fluorescence life time of the dye to be extracted from the experimental results. 2. Experimental work and analysis The PhC is grown from Rhodamine B dye-doped polystyrene colloids by convective self-assembly method [4]. The image from scanning electron microscope (SEM) in Fig.1(a) shows the expected hexagonal ordering parallel to the substrate. The PhC is infiltrated with gold nanoparticles with an average diameter of 40 nm so that their wavelength of LSPR may lie within the absorption band of the dye. The reflection spectra of PhC and GIPhC in Fig.1(b) indicate the wavelength of the stopband in these crystals. The stopband in GIPhC is red-shifted with reference to its value in PhC due to the change in effective index after infiltration. The fluorescence from the crystals is studied using an excitation wavelength of 347 nm. In spite of the lowering in reflectance from GIPhC in comparison to PhC, there is an enhancement in fluorescence from the dye in the case of GIPhC as seen in Fig.1(c). The spectra of dye absorption, dye emission, LSPR and the stopband overlap in our crystals.
(a) (b) (c) (d)
Fig.1. (a) SEM image for the periodic arrangement of colloids in PhC grown from colloidal diameter of 277 nm. The scale bar is 200nm. The stopband of PhC and GIPhC are shown in (b) while the fluorescence spectrum and decay are shown in (c) and (d) respectively.
The increased fluorescence from GIPhC has its origin in the LSPR of the gold nanoparticles [5]. The emission spectrum has a partial overlap with the LSPR band which in turn has a significant overlap with the absorption band of the dye. This has a cumulative effect of increased absorption and subsequent emission. This shows its effect on the fluorescence lifetime of the dye as well as seen in Fig.1(d). The dye has radiative and non-radiative components of fluorescence decay in the PhC but the non-radiative part is completely suppressed in the GIPhC as a consequence of the LSPR effect. This is seen clearly with the double-exponential and single-exponential fits shown in Fig.1(d). The radiative lifetime of the dye is also substantially reduced in GIPhC due to the resonant interaction enabled by the LSPR of the gold nanoparticles infiltrated in it. Acknowledgements: The work was partially supported by IRDE, Dehradun, India under the DRDO Nanophotonics program (ST-12/IRD-124) and by DST, India under the India-Taiwan S&T co-operation project (GITA/DST/TWN/P- 61/2014). References [1] H. P. Schriemer, H. M. van Driel, A. F. Koenderink, and W. L. Vos, Phys. Rev. A, 63, 011801-1 (2001). [2] P. Lodahl, A. F. van Driel, I. S. Nikolaev, A. Irman, K. Overgaag, D. Vanmaekelbergh and W. L. Vos, Nature, 430, 654-657 (2004). [3] D. Rout and R. Vijaya, Plasmonics, 10, 713-719 (2015). [4] Q. Yan, Z. Zhou and X. S. Zhao, Langmuir, 21, 3158-3164 (2005). [5] K. Ishikawa and T. Okubo, J. Appl. Phys., 98, 043502 (2005).
256 P-02-29
Plasmonic Optical Trapping by Elliptical Nanohole ffor Chiral Analysis Using Raman Optical Activity
Zi-Huan Huang, Fan-Cheng Lin and Jer-Shing Huang Department of chemistry, National Tsing Hua University, Hsinchu 30013, Taiwan E-mail address: [email protected]
Abstract: Due to the weak signal of circular dichroism (CD) effect, we designed and fabricated plasmonic structure to generate the concentrated chiral optical near field and enhance the optical chirality. The enhanced near filed can also provide trapping force to isolate, immobilize and manipulate the target nanoparticles. We have measured the stable optical trapping event and Raman spectrum, successfully.
Introduction Chiral molecules show slightly different absorbance of left- and right-handed circularly polarized light (CPL). Such circular dichroism (CD) effect can be used for the characterization of molecular chirality. Unfortunately, CD is usually very weak due to the mismatch between the pitch of CPL helix and the size of molecular chiral domain. To overcome such problem, we have designed and fabricated plasmonic elliptical nanoholes (Left panel, Fig. 1) to create the concentrated chiral optical near field based on localized surface plasmonic resonance (LSPR). The optical near field generated in our elliptical nanohole can also provide trapping force to isolate, immobilize and manipulate the target nanoparticles [1]. By controlling the polarization of the incident light, the chirality of the optical near field can be easily switched. When the object is trapped in the elliptical nanohole, the local refractive index changes dramatically, resulting in the increase of transmission intensity (Right panel, Fig. 1). By measuring the Raman scattering spectrum simultaneously, we can then obtain the information of the chemical composition of the target. Since the optical near field in the hole is circularly polarized, the Raman scattering also reveal the chirality of the target due to the Raman optical activity (ROA). Currently, we are working on the ROA of single polystyrene spheres coated with Fluorescein isothiocyanate (FITC) and bovine serum albumin (BSA). Our method has potential to achieve chiral chemical analysis on ultralow concentration. We anticipate applications in single protein analysis.
Fig. 1: (a) Scanning electron microscope (SEM) image of the elliptical nanohole on a single-crystalline gold film. (b) Time trace of transmission intensity showing the trapping of a 20 nm polystyrene sphere. State A and B are the light transmission through the hole without and with the particle trapping, respectively.ġ
References [1] Juan ML, Gordon R, Pang Y, Eftekhari F, Quidant R., "Self-induced back-action optical trapping of dielectric nanoparticles," Nature Physics. 5, 915-917(2009)
257 P-02-30
CombinedC Au-plasmonic nanoparticles with Ca/Sn doped polyhedral -Fe2O3 Nanocrystals for Photocatalytic production of hydrogen
Chien-Jung Peng1, Chia-Jui Li1, Wei-Hsuan Hung*1 1Department of Material Science and Engineering, Feng Chia University E-mail address: [email protected]
Abstract: In this research, large specific surface area bipyramidal and pseudocubic polyhedral -Fe2O3 nanocrystals were fabricated for hydrogen reduction in water splitting process with 532 nm laser irradiation. The photocatalytic activity of hematite is limited by relatively poor absorptivity, very short excited-state lifetime, and a short hole diffusion length. To address the limitation, Sn and Ca dopants were processed in these shape controlled hematite. With the additional dopants, both bipyramidal and pseudocubic -Fe2O3 hematite showed a significant improvement in the water splitting photocurrent response as a result of increased carrier density. Moreover, to exploit the enhancement from surface plasmon resonance (SPR), Au nanoparticle was decorated on the surface of Fe2O3 for increasing incident light absorption and suppressing charge recombination due to a strong field generated from collective oscillations of surface electrons. Subsequently, the water splitting photocurrent of Au/Ca-Sn-bipyramid 2 Fe2O3 photoelectrode can achieve 0.14 mA/cm in 1M NaOH at 0.6 V, which is approximately 3 times higher than that of the hematite photoelectrode. Finally, we evaluated the hydrogen production efficiency for the all photoelectrodes.
1. Introduction to main text format and page layout As a photoelectrode, hematite ( -Fe2O3) has attracting considerable attention due to its favorable optical band gap (2.2eV), chemical stability, low cost, nontoxicity, high resistance to corrosion. However, the photcatalyst activity of hematite is limited by several key factors such as relatively poor absorptivity[1] very short excited-state lifetime (ȕ10-12 s)[2] poor oxygen evolution reaction kinetics[3] a short hole diffusion length (2-4 nm)[4]. In this work, bipyramidal and pseudocubic two kinds of polyhedral -Fe2O3 nanocrystals were fabricated via a facile hydrothermal routes. The merits of these morphologies provide larger specific surface area for more reactive sites generation and fast interfacial charge collection. Incorporation of impurities in the hematite, Sn, Mg, Zn and Ti , has been reported for the benefit of the superior electrical and optical properties. According to the study from the Sivula et al. Sn can diffused from the FTO substrate at a high temperature (800 ʚ). Interestingly, in the our study the low temperature Sn diffusion was obtained due to the relatively high porosity in the bipyramidal and pseudocubic iron oxide film, which was proved by the result of XPS Concentrationȉdepth profile. We found Sn can diffused to the surface of Fe2O3 at 4 hours 450 ʚsintering. P-type doping have been carried out through chemical bath with calcium chloride as precursor. The plasmon resonant light enhanced approach was applied as another boost for achieving higher hydrogen production. Not only The surface plasmon resonance (SPR) electric field effects, but the plasmon-excited hot electrons from the plasmon decay can be transferred to the conduction band of adjacent semiconductor for additional hydrogen production. In the present work, modifications of the bipyramidal/pseudocubic hematite electrode by doping with Sn and Ca, and Au nanoparticles on the surface of -Fe2O3 thin film photoelectrode have been provided another improvement scheme for a higher photoelectrochemical hydrogen generation. 2. Figures and tables
Fig. 1. (a-d) SEM and TEM images of the as-prepared pseudocube/ bipyramid -Fe2O3 nanoparticles. (e) XPS Concentration–depth profile of the Sn doped Fe2O3 thin film photoelectrode. (f) Hydrogen production performance of bipyramid -Fe2O3 photoelectrode. 3. References [1] I. Cesar, K. Sivula, A. Kay, R. Zboril, M. Graetzel, J Phys Chem C, 113 (2009) 772-782. [2] N.J. Cherepy, D.B. Liston, J.A. Lovejoy, H. Deng, J.Z. Zhang, The Journal of Physical Chemistry B, 102 (1998) 770-776. [3] M.P. Dare-Edwards, J.B. Goodenough, A. Hamnett, P.R. Trevellick, Journal of the Chemical Society, Faraday Transactions 1: Physical Chemistry in Condensed Phases, 79 (1983) 2027. [4] K. Sivula, R. Zboril, F. Le Formal, R. Robert, A. Weidenkaff, J. Tucek, J. Frydrych, M. Gratzel, J Am Chem Soc, 132 (2010) 7436-7444.
258 P-02-33
Fano-like resonance on asymmetric stacked nanoantenna
Zhan-Hong Lin (㜿⯽泣), Fan-Cheng Linġ(㜿䭬婈), and Jer-Shing Huang (湫⒚⊛) Department of Chemistry, National Tsing Hua University, Hsinchu 30013, Taiwan E-mail: [email protected]
Abstract: Upon excitation gold nanorods exhibit localized surface plasmon resonance. The resonance wavelength of longitudinal modes scales with aspect ratio of the nanorods. When two rods are stacked, the modes on each rod couple via the near field in the sub-3nm gap [1]. The strong coupling results in two hybrid modes with different modal profiles and separated with an asymmetric energy splitting [2,3]. Depending on the symmetry and frequency of the excitation, hybrid modes can be selectively excited. Therefore, nanorod dimers may function as nanoantennas with enhanced field in the gap or as high-Q plasmonic cavities depending on the coupling between two rods.
In this work, we theoretically investigate the coupling of longitudinal plamonic modes in asymmetric stacked antennas. Gradually tuning the length of down rod and keeping the top rod, we have observed coupling behavior similar to adiabatic avoided curve crossing. The asymmetry of energy splitting is found to be different for dipole-dipole coupling and dipole-quadrupole coupling. Since the dark quadrupolar modes radiate less efficient than the dipolar modes, the far-field scattering spectrum may exhibit dip in contrast to peak. This makes it possible to engineer the resonance spectrum of nanorod dimers simply by linking rods with desired length. The result is insightful and provides a guideline for plasmonic enhanced spectrum engineering.
Fig. 1. (a,b) Dark-field and SEM images of stacked antenna. Length of slit = 100 nm (a) and 500 nm (b). (c) SEM images of stacked antenna.
Fig. 2. Dark-field scattering spectrum of stacked antenna.
References [1] D. W. Pohl, S. G. Rodrigo, and L. Novotny, Appl. Phys. Lett. 98, 023111 (2011). [2] J. S. Huang,J. Kern,P. Geisler,P. WeinmannM. Kamp, A. Forchel, P. Biagioni, and B. Hecht, Nano Lett. 9, 3608–3611 (2009). [3] M. Abb, Y. Wang, P. Albella, C. H. de Groot, J. Aizpurua, and O. L. Muskens, ACS Nano. 6, 6462–6470 (2012).
259 P-02-34
TransmittedT Phase: A Yardstick for Predicting Extreme Acoustic Properties in Space-coiling Metamaterials
Santosh K. Maurya1, Abhishek Pandey1, Shobha Shukla1, Sumit Saxena1* 1Nanostructures Engineering and Modeling Laboratory, Department of Metallurgical Engineering and Materials Science, Indian Institute of Technology Bombay, Mumbai, MH, India 400076 * [email protected]
Abstract: Manipulation of waves by artificially engineered structures has led to promising applications such as cloaking, sub-wavelength focusing, surface wave manipulation, extraordinary transmission etc. This concept has been extended to acoustic waves. Akin to electromagnetic response in optical metamaterials, acoustic metamaterials are designed by equivalently demanding negative mass density and bulk modulus. Recent advances using experiments and finite element modeling have shown that double negativity can be achieved by coiling up space in 2D. We have investigated the transmitted wave properties such as phase and amplitude to understand the correlation of extreme acoustic properties in 2D sub- wavelength space coiling acoustic metamaterials with the changes in transmitted wave properties. Comparison of the changes in the relative transmitted phase of total acoustic pressure with the extreme acoustic parameters suggests that the transmitted phase can be used as a yardstick to estimate the presence of forbidden and extreme acoustic bands in space- coiling metamaterials.
260 P-02-35
Investigation of plasmonic contribution in extraordinary transmission through micro hole
Suyog R. Hawal1, Santosh Kumar Maurya1, Raghvendra Pratap Chaudhary1, Tushar Karnik1, Rohit Jain1, Saurabh Awasthi2, Shobha Shukla1 and Sumit Saxena1* 1Nanostructures Engineering and Modeling laboratory, Department of Metallurgical Engineering and Materials Science, Indian Institute of Technology Bombay, MH, India 400076 2Fakultat Technologie and Bionik, Rhine-Waal University of Applied Sciences, Kleve, Germany-47533 * Corresponding author:- [email protected]
Abstract: Novel properties of miniaturized plasmonic devices to concentrate light in nanoscale volume have created a runaway effect in the development of efficient nanophotonic devices. Recent research has shown that it can be achieved using nanohole aperture. However, the extraordinary transmission and focusing through nanoholes holds inherent complexities for fabrication and information processing due to its size. Polarization independent broadband plasmonic microlenses have shown extra ordinary transmission in quasi near field with enhanced transmission efficiency. These structures not only enhance the transmitted wave intensities significantly as compared to nanohole apertures but are also simpler to fabricate and incorporate with nanophotonic devices. Here we investigate the contribution of different optical phenomena in transmission using FDTD simulations. Further analysis and results will be presented.
261 P-02-36
EnhancedE UV-LED output intensity via hyperbolic metamaterial
Kun-Ching Shen1, Chin-Yu Chang2, Min-Hsiung Shih1, and Yuh-Jen Cheng1, * 1Research Center for Applied Science, Academia Sinica, Taipei 11529, Taiwan 2Nano-Electro-Mechanical-System (NEMS) Research Center, National Taiwan University, Taipei 10617, Taiwan *[email protected]
Abstract: A large UV LED output intensity enhancement was demonstrated by the introduction of an Ag/TiO2 multilayer hyperbolic metamaterial on a 385-nm light emitting device. Through the optimal design in thickness and pair number of the Ag/TiO2 multilayer, the metamaterial structure creates a steep hyperbolic dispersion curve along the in-plane direction in k space. A wide range of in-plane k vector corresponds to a narrow range of out- of-plane k vector on the isofrequency surface. When this hyperbolic metamaterial (HM) is fabricated on top of the UV quantum well (QW) LED, the photons emitted from QWs are injected to the HM and redirected and traveled perpendicularly within the HM. This results in a large LED output power enhancement.
Recently, UV-LEDs have received renewed attentions due to their potential for important applications, such as Hg-free UV lamps, water purification and biochemical detection. In general, for blue- and green- LEDs, the indium fluctuations in the InGaN/GaN QWs provide localized states. These states can enhance LED radiative efficiency. The indium-free QWs of UV-LEDs have less significant localized states to enhance radiative efficiency as compared with blue- and green-LEDs. To satisfy the power requirement, the internal quantum efficiency of the UV LEDs have been improved to a high level of 70% by the high crystal quality QW structure. However, they still suffer from relatively low external quantum efficiency due to the lack of better light extraction mechanism. In this study, we employ a metal/dielectric multilayer structure as a plasmonic cavity to demonstrate an enhancement in LED output. The multilayer structure is composed of Ag and TiO2 material. Through a proper design in thickness and pair number of the Ag/TiO2 multilayer, the dispersion relation of the multilayer changes from an ellipsoid to a hyperboloid. The sharp hyperbolic horn curve along the in-plane direction indicates that a wide range of in-plane k vectors corresponds to a narrow range of out-of-plane k vector. The large angle of incidence of photon can be effectively collected and transferred to vertical direction without the limit of total internal re ection. The HM multilayer was deposited on the surface of a 385-nm QW LED surface separated by a thin dielectric layer. A series of pattern area from 1 x 1, 0.5 x 0.5, 0.2 x 0.2, to 0.1 x 0.1 m2 were fabricated by focused ion beam. A significant multiple increases in light output power was observed under optical pumping for the UV-LED with a 0.5 x 0.5 m2 HM. This significant improvement was attributed to the enhanced light extraction via the HM array structure incorporation. The optimal design of the HM structure will be discussed.
262 P-03-01
Photonic Band Gaps Induced by Strong Acousto-Opticti Interaction in Hybrid Plasmonic-Photonic Slab Waveguides
Jheng-Hong Shih,1 Jin-Chen Hsu,2 Tzy-Rong Lin1,3* 1Department of Mechanical and Mechatronic Engineering, National Taiwan Ocean University, Taiwan 2Department of Mechanical Engineering, National Yunlin University of Science and Technology, Taiwan 3Institute of Optoelectronic Sciences, National Taiwan Ocean University, Taiwan E-mail address: [email protected]
Abstract: We propose dynamic modulation of acousto-optic (AO) interaction, originated from interface and bulk effects of a slab, in a hybrid plasmonic-photonic waveguide by acoustic waves to generate photonic band gaps (PBGs). The hybrid waveguide consists of a dielectric submicron slab separated from a metal surface by a nanoscale air gap. The coupling between the plasmonic and photonic modes across the gap enables strongly interaction with phononic modes through acoustic perturbation of the dielectric slab. Results show that multiple scatterings through the enhanced periodic AO interaction open Bragg PBGs; and further, tunable bandgap widths and optical transmittances are achieved at telecommunication wavelengths. This study provides opportunities for various applications in tunable optomechanical and AO devices, light modulation, and optical communication.
In recent years, the formation of allowed and forbidden bands of frequency of classical waves in periodic media has received great interests. Similar to crystalline solids, which exhibit electron gaps, periodic dielectric and elastic structures, which are known as the photonic and phononic crystals, can exhibit photonic and acoustic band gaps, respectively. Recent developments in photonic crystals have demonstrated the possibility of controlling optical energy in compact and highly integrated micro and nanoscale devices, which provide promising applications for the next-generation of photonics technology [1]. Conventional photonic crystals are constructed by two or more materials in which the periodical inclusions and the lattice constant are related to the photonic band gap (PBG) frequency. To attain PBGs in the optical range of the spectrum, the lattice constant of the photonic crystals has to be brought down to the submicron scale. Very pure semiconductors (as insulators) are commonly used for this purpose because of their large dielectric constants and minimal light absorption. Such structures with PBGs in the optical region are of interest in micro/nano lasers and optoelectronics. In photonic crystals, most studies were based on passive structures in which the PBGs were immutable. Some studies have demonstrated tunable PBGs by external fields (e.g., electric, deformation, or strain fields). Recently, nonlinear modulation of light using acoustic phonons through the called acousto-optic (AO) interaction has been proposed [2-5]. Acoustic waves with frequencies in the range from hundreds of megahertz to several gigahertz can be generated by piezoelectric thin film transducers or electrostatic forces in microstructures. Engineered optical modes in a simultaneous photonic and phononic band gap structure have been used to achieve an enhanced modulation for active control of the photonic structures by acoustic wave energy. Promising applications include the AO modulator, optical switch and the intensity and frequency modulation for micro/nano lasers and sensors. In this paper, we report the creation of PBGs in a hybrid plasmonic-photonic slab waveguide by strong AO interaction, including the modulation of interface and bulk effects of a dielectric slab through excitation of their acoustic eigenmodes, using the finite-element method (FEM). Specifically, we consider a submicron GaAs slab lying on an Ag metal surface separated by a nanoscale air gap. Plasmonic modes are coupled with photonic modes across the gap to form hybrid modes, which are highly confined in the low-loss air gap region. The hybrid modes enable strong interaction with the phononic modes through acoustic perturbation of the dielectric slab. The occurrence of the strong forbidden effect is due to the enhanced AO interaction, resulting in the modulation of bandgap widths and optical transmittances over a broad range at telecommunication wavelengths.
[1] M. Campbell, D. N. Sharp, M. T. Harrison, R. G. Denning, and A. J. Turberfield, Nature 404, 53 56 (2000). [2] T.-R. Lin, C.-H. Lin, and J.-C. Hsu, Journal of Applied Physics 113, 053508-1 053508-8 (2013). [3] J.-C. Hsu, C.-H. Lin, Y.-C. Ku, and T.-R. Lin, Optics Letters 38, 4050 4053 (2013). [4] T.-R. Lin, C.-H. Lin, and J.-C. Hsu, Scientific Reports 5, 13782-1–13782-11 (2015). [5] J.-C. Hsu, T.-Y. Lu, and T.-R. Lin, Optics Express 23, 25814–25826. (2015).
263 P-04-01
ModeMd controlled near-infrared laser action made with the composites of solution processed lead halide perovskite and dielectric nanospheres
Packiyaraj Perumal a, b, c, Min-Hsiung Shih d, and Yang-Fang Chen * a, c a Department of Physics, National Taiwan University, Taipei 106, Taiwan b Nano Science and Technology Program, Taiwan International Graduate Program, Academia Sinica and National Taiwan University c Center for Emerging Material and Advanced Devices, National Taiwan University, Taipei 106, Taiwan d Research Center for Applied Sciences, Academia Sinica, Taipei 115, Taiwan * E-mail address: [email protected]
Abstract: Mode controlled room-temperature near-infrared (NIR) laser action in inorganic- organic perovskite semiconductors coupled with SiO2 nanospheres has been demonstrated. The spherical nanocavities of SiO2 nanospheres serve as laser resonators, and the laser oscillation was achieved through the coupling of whispering gallery mode (WGM) with perovskite gain material. It is found that the lasing spectra can be well manipulated by the size of SiO2 nanospheres. Three-dimensional finite-element method simulation was performed to understand the lasing modes. The discovered laser action and inherent chemical stability of perovskites not only render them significant practical use in various optoelectronic devices, but also provide a potential extension towards highly efficient NIR emitting devices for laser photonics, solid-state lighting and display applications.
1. Introduction Inorganic-organic lead halide perovskite semiconductors, methyl ammonium lead iodide (MAPbI3), with a bandgap around 1.5-1.6 eV have been used extensively as a light harvester in solar cells over the past several years. Recently, it has also emerged as a highly-promising material for optoelectronic devices such as light emitting diodes (LEDs)[1], lasers[2,3] owing to the excellent light emission, high absorption coefficient, and low non-radiative recombination[4]. The optical processes associated with whispering gallery modes (WGMs) within very small spherical resonators are very attractive because of their highly promising performance in the realization of optoelectronic devices[5]. In this work, we focus on one-step spin coating process of mixed perovskite solution (CH3NH3I and PbI2) with different concentration for an attractive gain properties by examining the stimulated emission in SiO2 nanospheres coated glass substrate. To couple perovskite gain material into spherical resonator, SiO2 nanospheres was used as nanocavities with an average diameter from 500 nm to 170 nm. The underlying origin of the laser with large-scale, highly intensed, controllable wavelength, narrow-linewidth (<1.5 nm) mode resonances can be realized in terms of the waveguiding and scattering media within the nanosphere network. 2. Figures
“Fig. 1. (a)Schematic representation for coupling of MAPbI3 and SiO2 nano-sphere, (b) Corresponding emission spectra, (c) calculated WGM resonance mode”. 3. References [1] Z. K. Tan, R. S. Moghaddam, M. L. Lai, P. Docampo, H. J. Snaith and R. H. Friend, Nat Nanotechnol. 9, 687-692 (2014). [2] G. Xing, N. Mathews, S. S. Lim, N. Yantara, X. Liu, D. Sabba, S. Mhaisalkar and T. C. Sum, Nat. Mater. 13, 476-480 (2014). [3] B. R. Sutherland, S. Hoogland, M. M. Adachi, C. T. O.Wong, E. H. Sargent, ACS Nano 8, 10947 (2014). [4] G. Xing, N. Mathews, S. Sun, S. S. Lim, Y. M. Lam, M. Gratzel, S. Mhaisalkar and T. C. Sum, Science 342, 344-347 (2013). [5] T.-M. Weng, T.-H. Chang, C.-P. Lu, M.-L. Lu, J.-Y. Chen, C.-H. Nieh and Y.-F. Chen, ACS Photonics 1, 1258-1263 (2014).
264 P-04-02
High Efficiency Mid-infrared Acetylene Filled Fiber LLaser
Xiaosheng Huang,1 Feng Luan,2 Seongwoo Yoo,1,* and Ken-Tye Yong,1,* 1OPTIMUS, The Photonics Institute, School of Electrical and Electronics Engineering, Nanyang Technological University, Singapore 639798, SingaporeE-mail address: (8-point type, centered, italicized) 2College of Optoelectronics, Shenzhen University, Shenzhen 518060, China *[email protected] *[email protected]
Abstract: The setup to obtain high efficiency mid-infrared emission is designed and demonstrated. An improved design for hollow core anti-resonant fiber (HAF) is presented to achieve higher conversion efficiency.
1. Introduction Compact mid-infrared (mid-IR) fiber lasers have attracted great attention recently due to their potential applications in security, defense, atmosphere monitoring and medicine [1-3]. It is known that gas fiber lasers can be used as an effective mean to generate mid-IR emission [4, 5]. In the previous work of [4], the first mid-IR gas fiber laser was demonstrated by employing acetylene-filled Kagome structure hollow core fiber (KF). However, the conversion efficiency was only ~1% and this is due to the high transmission loss of Kagome fiber (20 dB/m) at the corresponding laser wavelength. In order to improve the Raman conversion efficiency, we have designed and fabricated a hollow core fiber with split cladding structure (HC-SCF) that benefits from lower transmission loss than KF. The fabricated fiber and its transmission spectrum are shown in fig. 1 (a). The fiber has high transmission at 1.55 m, and it can be estimated from Eq. (1). The fiber has a core wall thickness of t = 2.55+) ,")'2)& 1) )*-5)20 ,1+'11'-,)*-11) 2 3.27 +)ʚ,-0+ *'8#")$0#/3#,!7)8)Ɣ) STXUYʛT The HC-SCF is served as the laser cavity and it works together with the acetylene gas (gain medium) and a 1.55 m pulse laser to generate the laser emission at 3.27 m. The basic setup schematic is illustrated in fig. 1 (b). 2. Figures and tables
Fig. 1 (a) Blue line shows the transmission spectrum of 5.6 m fabricated fiber, red dash line corresponds to the theoretical resonant wavelength (high loss), fiber core wall thickness t is 2.55m, inset shows the cross section of the fiber. (b) Setup to demonstrate mid-IR laser emission. PL: pulse laser; /2: half-wave plate; /4: quarter-wave plate; PBS: polarizing beam splitter; M: mirror; CL: coupling lens; GC: gas cell; OSA: optical spectrum analyzer; BPF: band pass filter; PM: power meter. 3. Equations ǭ v ̀ƔͦƐ/Ɛ ) ͯͥ Z (1) Here, F is normalized frequency, t is core wall thickness, is wavelength F equal to integers correspond to resonant (high loss) wavelengths, n = 1.45 is the refractive index of cladding material. 4. References [1] C. Carbonnier, H. Tobben, and U. B. Unrau, “Room temperature CW fiber laser at 3.22 m,” Electron. Lett. 34, 893–894 (1998). [2] J. Li, D. D. Hudson, and S. D. Jackson, “High-power diode-pumped fiber laser operating at 3 m,” Opt. Lett. 36, 3642–3644 (2011). [3] S. D. Jackson, “Towards high-power mid-infrared emission from a fiber laser,” Nat. Photonics 6, 423–431 (2012). [4] A. M. Jones, A. V. Nampoothiri, A. Ratanavis, T. Fiedler, N. V. Wheeler, F.Couny, R. Kadel, F. Benabid, B. R. Washburn, K. L. Corwin, and W. Rudolph, “Mid-infrared gas filled photonic crystal fiber laser based on population inversion,” Opt. Express 19, 2309–2316 (2011). [5] Z.Wang, W. Belardi, F. Yu, W. J. Wadsworth, and J. C. Knight, “Efficient diode-pumped mid-infrared emission from acetylene-filled hollow-core fiber”, Opt. Express 22, 21872–21878 (2014).
265 P-04-03
Lasing in nano-grating with Fano resonance
Ya-Bin Chen1, Zi-Lan Deng2, and Jian-Wen Dong1,* 1. Sun Yat-Sen University, Guangzhou, 510275, China 2 Shenzhen University, Shenzhen, 518060, China E-mail: [email protected]
Abstract: We propose a kind of lasing scheme in a nano-grating that enables to independently control the dark and bright modes in Fano resonance by adjusting the widths of the wide and narrow metal stripes, respectively. In this way, the nano-grating is designed at will, in which the Fano lineshape can be almost perfectly consistent with the absorption and emission profiles of the gain medium. We give out an optimal example of metal nano-grating and Rhodamine dye molecules, and also illustrate the lasing dynamic process with minimum lasing threshold and maximum lasing slope efficiencies. Our findings may provide a new way on plasmon laser with low threshold and high efficiency.
Plasmon laser has been attracted great attention at length scales below diffraction limit. It has been demonstrated not only in single nanocavity systems, but also been observed in periodic nanoplasmonic structures [1, 2, 3]. Here, we propose a new kind of lasing scheme in nano-grating with compound 1D lattice. Figure 1 shows the schematic of the nano-grating structure with three slits in each supercell [4]. The slit width is w = 45 nm, and the grating thickness is h = 170 nm. The whole structure is immersed into the gain medium (e.g. Rhodamine dye molecules) with the thickness of 300 nm. There exist a bright mode and dark mode in the nano- grating, due to the inter-couples among the cavity modes in each slit. For the dark mode with strong near-field confinement, it is out-of-phase and exhibits sharp reflection peak; while the bright mode is in-phase radiation to far-fields and exhibits broad reflection valley. The most interesting issue is that such two modes can be independently controlled by tuning the widths of the fat and thin metal stripes. For example, when keeping the width of the fat metal strip unchanged at dG=315 nm while changing the width of the thin metal stripe dL from xx to xx nm, the resonant frequency of the bright mode is nearly fixed near the frequency of 660 nm, but the dark mode has a minimum frequency value at 693 nm. It inspires that one can fine tune the width of the thin metal strip dL to match the emission peak of different gain medium. Similarly, one can also delicately design the width of the fat metal strip dG to match the absorption peak of various gain medium. It enables the flexibility to choose the gain medium and the corresponding cavity surrounding in nanoscale. Based on such guideline, we investigate a lasing system consisting of nano-grating and sudanming by using self-consistent finite element method [3]. We show the lasing dynamic process with both the match and mismatch nano-grating. When it well matches, the dark mode will provide higher feedback and amplification than those of the mismatch system. Consequently, when the same optical pump power is applied, the match case will have shorter lasing onset time and higher output power than the mismatch structure, confirming by the time evolutions of the lasing field shown in Fig. 2. More calculations can conclude that the perfect-match nano-grating system will have minimum threshold and maximum lasing slope efficiencies, providing a new way on plasmon laser.
Fig. 1 (a) Schematic of the nano-grating superlattice structure. The unit-cell consists of two thin metal strip, one fat metal strip, and three air slits. dL and dG can independently control the frequency of the dark and bright modes in Fano resonance. (b) Time evolution of the lasing field calculated with the same pump-power for both well-match (red) and mismatch (blue and green) situations. Note that the match system will have shorter lasing onset time and higher output power than those of the mismatch case.
References [1] R. F. Oulton, V. J. Sorger, T. Zentgraf, R.-M. Ma, C.Gladden, L. Dai, G. Bartal, and X. Zhang, Plasmon lasers at deep subwavelength scale, Nature 461, 629 (2009). [2] Tim Pickering, Joachim M. Hamm, A. Freddie Page, Sebastian Wuestner & Ortwin Hess, Cavity-free plasmonic nanolasing enabled by dispersionless stopped light, Nat. Commun, 5972, 5:4972, (2014). [3] Zi-Lan Deng and Jian-Wen Dong, Lasing in plasmon-induced transparency nanocavity, Opt. Express 21, 020291 (2013). [4] Ya-Bin Chen, Zi-Lan Deng, and Jian-Wen Dong, to be submitted to Opt. Express.
266 P-04-04
High-Efficiency Broadband High-Harmonic Generationti from a Single Nonlinear Crystal
Chen-Yang Hu1, Bao-Qin Chen2, Zhi-Yuan Li1,2* 1Laboratory of Optical Physics, Institute of Physics, Chinese Academy of Sciences, P.O. Box 603, Beijing 100190, China 2School of Physics, South China University of Technology, Guangzhou 510640, China E-mail address: [email protected]
Abstract:Since the invention of the laser, nonlinear optics has become a popular and efficient routine for expanding the frequency window of lasers from ultraviolet to visible, infrared, and terahertz bands, and for generating broadband coherent light sources and ultrafast pulse lasers. However, it’s still difficult to realize high-harmonic generation (HHG) in a single crystal, because many nonlinear up-conversion processes must be simultaneously adopted with phase matching. Instead, a chain of two or more individual nonlinear crystals with cascaded second- harmonic generation (SHG) and sum-frequency generation (SFG) is used, but the experimental setup is complicated and the conversion efficiency is low. In recent years, our group makes many efforts to accomplish high-efficiency frequency conversion by quasi-phase-matching (QPM) technology. We have realized multi-direction high-efficiency second harmonic generation [1] and simultaneous broadband generation of second and third harmonics [2] by nonlinear photonic crystals. Very recently, our group realized simultaneous 5th–8th harmonic generation (HG) from a single chirped periodic poled lithium niobate (CPPLN) nonlinear crystal [3]. The CPPLN crystal offers a series of broad QPM bands with a considerably large effective nonlinear susceptibility eff and freely designated spectral position to support SHG and SFG in the different wavelength bands that are necessary for various-order HHG. Upon illumination of a mid-IR femtosecond pulse laser, we have observed the generation of an ultrabroadband visible white light beam corresponding to 5th–8th HG with a record high conversion efficiency of 18%. The CPPLN nonlinear crystal with HHG opens up a new avenue for greatly expanding the power to engineer high-order nonlinear interactions in solid state materials and can find application in supercontinuum generation, ultrafast lasers, frequency combs, large-scale laser displays, and short-wavelength laser sources.
Reference [1] Bao-Qin Chen, Chao Zhang, Rong-Juan Liu, and Zhi-Yuan Li, "Multi-direction high-efficiency second harmonic generation in ellipse structure nonlinear photonic crystals", Appl. Phys. Lett. 105, 151106 (2014). [2] Bao-Qin Chen, Ming-Liang Ren, Rong-Juan Liu, Yan Sheng, Bo-Qin Ma, Chao Zhang, and Zhi-Yuan Li*, "Simultaneous Broadband Second and Third Harmonic Generation in Chirped Nonlinear Photonic Crystal", Light: Science & Application 3, e189 (1-6) (2014) [3] Bao-Qin Chen, Chao Zhang, Chen-Yang Hu, Rong-Juan Liu, and Zhi-Yuan Li*, "High-Efficiency Broadband High-Harmonic Generation from a Single Quasi-Phase-Matching Nonlinear Crystal", Phys. Rev. Lett. 115, 083502 (2015)
267 P-05-01
EmissionE Enhancement of Quantum Rods by Self- assembled Plasmonic Nanoparticles
Ming-Xue Huanga, Fan-Cheng Linb , Chen-Hsien Huang b and Jer-Shing Huangb aDepartment of Biomedical engineering and environmental sciences, National Tsing Hua University, Hsinchu 30013, Taiwan bDepartment of Chemistry, National Tsing Hua University, Hsinchu 30013, Taiwan E-mail address: [email protected]
Abstract: The brightness of Quantum-rods (Q-rods) is usually much lower than that of quantum-dots (QDs) [1]. Its fluorescent emission can efficiently enhanced by linking to plasmonic nanoparticles that sever as optical antennas. To obtain the optimal conditions for brightness enhancement, the finite-difference time-domain (FDTD) method was used for numerical analysis. Here, we find out that the five-nanometer link with head-to-head between the Q-rod and a nanoparticle give the beat fluorescent enhancement of Q-rods.
Introduction Quantum rods (Q-rods) can emit linearly polarized fluorescence [2], which is promising for applications in modern electronic devices and orientation-sensitive bio-imaging [1]. However, the quantum yield of Q-rods is lower than 50%, rendering its real applications impractical., rendering its real applications impractical. Therefore, finding an efficient approach to enhance the brightness of Q-rods’ polarized emission becomes an important issue for Q-rods’ practical applications. Plasmonic metallic nanoparticles serve as optical nanoantennas to concentrate the near-field and strengthen the nanoscale light-matter interaction, which results in the excitation enhancement. In addition, it can provide additional optical states and increase the quantum yield of the illuminophore [3]. By the two enhancements, the linearly polarized fluorescence will be brightened. In this work, we will use self-assembled silver nanoparticles to link with Q-rods. For the achievement of optimal connections such as the relative position and distance between Ag NPs and Q-rods, the finite-difference time-domain (FDTD) method was used to numerically analyze. Here, the FDTD reveals that the linking of the Q-rod and the silver nanoparticle in head-to-head and 5 nm apart gives the most effective brightness enhancements of Q-rods.
[1] Aihua Fu; Gu, W.; Boussert, B.; Koski, K.; Gerion, D.; Manna, L.; Gros, M. L.; Larabe, C. A.; Alivisatos, A. P., Semiconductor Quantum Rods as Single Molecule Fluorescent Biological Labels. Nano letters. 1, 179-182 (2006). [2] Hu, J.; Li, L.-s.; Yang, W.; Manna, L.; Wang, L.-w.; Alivisatos, A. P., Linearly Polarized Emission from Colloidal Semiconductor Quantum Rods. Science. 292, 2060-2063 (2001). [3] Kinkhabwala, A.; Yu, Z.; Fan, S.; Avlasevich, Y.; Müllen, K.; Moerner, W. E., Large single-molecule fluorescence enhancements produced by a bowtie nanoantenna. Nature Photonics. 3, 654-657 (2009).
268 P-05-02
Plasmon-Mediated Self-Assembly of Gold Nanorodsd
Hsueh-Yu Chao1, Wu-Chun Lin1, Mao-Kuen Kuo1, Jiunn-Woei Liaw2,3,4* 1Institute of Applied Mechanics, National Taiwan University, Taiwan 2Department of Mechanical Engineering, Chang Gung University, Taiwan 3Center for Biomedical Engineering, Chang Gung University, Taiwan 4Medical Physics Research Center, Institute for Radiological Research, Chang Gung University/Chang Gung Memorial Hospital, Taiwan E-mail address: [email protected]
Abstract: The plasmon-mediated self-assembly of two or three gold nanorods (GNRs) driven by linearly polarized light was studied theoretically. We used the multiple multipole method to analyze the optical forces and torques exerted upon these coupled GNRs to estimate the self-assembly pattern. The results show that the end-to-end or side-by-side coalescence of these GNRs could be induced depending on the wavelength.
1. Introduction Recently, the light-matter interaction of gold or silver nanoparticles (NPs) has attracted a lot of attention [1]. Through the light manipulation, the self-assembly of NPs can be carried out [2]. If two nearby spherical gold or silver NPs with a distance less than 100 nm is irradiated by a linearly polarized (LP) light, the short- range interaction will make them attracted by each other, and the central line will be aligned parallel to the light’s polarization [1, 3]. On the other hand, although the manipulation on a single gold nanorod (GNR) or nanowire by LP light has been studied [1, 4-6], the interaction of multiple nearby GNRs is still unclear. In this paper, the self-assembly of two or three adjacent GNRs driven and aligned by the optical forces and torques as irradiated by a LP light is studied theoretically. 2. Method We used the multiple multipole (MMP) method to analyze the optical forces and torques exerted upon multiple coupled GNRs suspended in water. Through these optical forces and torque in terms of the surface integrals of Maxwell’s stress tensor, we estimated their self-assembly pattern. We studied several cases with different initial GNRs’ postures for a full wavelength range from visible light to near infrared to estimate the possible outcome. 3. Results and Discussion We studied the optical forces and torques versus wavelength upon two identical GNRs (r= 15 nm and L= 120 nm) irradiated by an x-polarized light. These GNRs lies on the xy plane with a gap of 20 nm between their ends and typical postures of 45o with respect to y axis. Our results show that the mechanical responses, particularly the optical torque, are wavelength-dependent. As the wavelength is longer than 865 nm, the two GNRs tend to be aligned parallel to the polarization of LP light by the z-component optical torques. In addition, the x-component optical forces exhibit the attraction. As a result, they could self-assembly with the end-to-end coalescence eventually. In contrast, as the wavelength is less than 865 nm, they will be aligned in perpendicular to the LP light by the z-component optical torques and attracted by each other due to the attractive forces in x-direction; they eventually contact with each other to achieve a side-by-side self-assembly. On the other hand, sometimes the two adjacent GNRs could repulse each other, so no coalescence occurs. For example, if they initially lie on the xy plane with special postures on the two sides of x axis, the repulsive forces are observed in full spectra of optical y-component forces. 4. Conclusion Our results show that the short-range light-matter interaction of two GNRs irradiated by LP light can perform attraction or repulsion, depending on their initial relative postures. For the attraction, the end-to-end or side-by-side coalescence could be induced, depending on the wavelength.
[1] L. Tong, V. D. Miljkovi , and M. Käll, Nano Lett. 10, 268-273 (2010). [2] Y. Bao, Z. Yan, and N. F. Scherer, J. Phys. Chem. C 118, 19315 19321 (2014). [3] J.-W. Liaw, T.-Y. Kuo, and M.-K. Kuo, J. Quant. Spectrosc. Radiat. Transfer 170, 150-158 (2016) . [4] J.-W. Liaw, W.-J. Lo, and M.-K. Kuo, Opt. Express 22(9), 10858-10867 (2014). [5] J.-W. Liaw, W.-J. Lo, W.-J. Lin, and M.-K. Kuo, J. Quant. Spectrosc. Radiat. Transfer 162, 133-142 (2015). [6] J.-W. Liaw, Y.-S. Chen, and M.-K. Kuo, Opt. Express 22, 26005-26015 (2014).
269 P-05-03
Light-DrivenL Self Assembly of Gold Nanoparticles
Shang-Yang Yu1, Hariyanto Gunawan1, Shiao-Wen Tsai2,3, Yun-Ju Chen1, Jiunn-Woei Liaw1,2,4* 1Department of Mechanical Engineering, Chang Gung University, Taiwan 2Center for Biomedical Engineering, Chang Gung University, Taiwan 3Institute of Biochemical and Biomedical Engineering, Chang Gung University, Taiwan 4Medical Physics Research Center, Institute for Radiological Research, Chang Gung University/Chang Gung Memorial Hospital, Taiwan Corresponding author: [email protected]
Abstract: A method of using linearly-polarized (LP) laser beam to manipulate gold nanoparticles (GNPs) for self-assembly into GNP-chains is proposed. We used LP 785-nm laser to irradiate a drop of gold colloid on a glass slide at room temperature, where the laser power is low. We found the formation of GNP-chains. This phenomenon could be caused by the optical forces and toques induced by LP light.
1. Introduction In the past decays, a variety of methods have been proposed and developed for the self-assembly of gold nanoparticles (GNPs) in water suspension, e.g. using ligand, polymer or DNA to link these nanoparticles [1,2]. Recently, using laser to induce self-assembly of GNPs was developed, in particular the femtosecond laser [3- 5]. Because the light-matter interaction (the plasmon effect) of GNPs is significantly strong in the regime of visible light to near infrared, the light-driven self-assembly of GNPs is worth exploring further. In this paper, we demonstrated the feasibility of using a linearly polarized (LP) continuous-wave (CW) laser to manipulate the self-assembly of GNPs. 2. Method A droplet of gold colloid on a glass was irradiated by a LP CW laser beam of 785 nm. The power of laser is around 10 mW. The average size of GNPs we is around 50 nm, and the surface plasmon resonance (SPR) is at 537 nm. The concentration of gold colloid is 10 ppm, and the volume of droplet is 3 L. We utilized field-emission scanning electron microscopy (FE-SEM) to observe the morphology of nanostructures. We varied the laser power, exposure time, volume of droplet, and concentration of GNPs to obtain the optimal conditions of fabricating GNP-chains. 3. Result and Discussion After ten-minute exposure of LP NIR laser beam with low power, we turned off the laser and dried the sample in air. After that, FE-SEM was used for observation. We found that a lot of aligned GNP-chains were formed on the glass, where GNPs were coalesced. We thought that the self-assembly of GNPs could be in relevance to the optical forces and torques induced by LP light. Moreover, the plasmonic heating at the junctions of adjacent GNPs might play a crucial role for sintering them. If the exposure time is longer, mesoscale structures could form. 4. Conclusion The feasibility of using LP CW laser for inducing the light-driven self-assembly and coalescence of GNPs in droplet to form linear GNP-chains has been demonstrated. We believed that this self-assembly is related to the optical forces and torques induced by LP light. This new approach might pave the way to the bottom-up assembly of GNPs for fabricating micro-sized nanowires.
[1] K. G. Thomas, S. Barazzouk, B. Ipe, S. T. S. Joseph, and P. V. Kamat, J. Phys. Chem. B 108(35), 13066– 13068 (2004). [2] D. Fava, Z. Nie, M. A. Winnik, and E. Kumacheva, Adv. Mater. 20, 4318–4322 (2008). [3] Y. Tanaka, H. Yoshikawa, T. Itoh, and M. Ishikawa, Opt. Express 17, 18760-18767 (2009). [4] M. Son, S. Jeong, and D.-J. Jang, J. Phys. Chem. C 118(11), 5961–5967 (2014). [5] L. O. Herrmann, V. K. Valev, C. Tserkezis, J. S. Barnard, S. Kasera, O. A. Scherman, J. Aizpurua, and J. J. Baumberg, Nat. Commun 5, 4568 (2014).
270 P-05-04
Octahedral anatase particles modified with plasmonici nanoparticles with enhanced photocatalytic activity
Zhishun Wei, Maya Endo, Bunsho Ohtani, Ewa Kowalska Institute for Catalysis, Hokkaido University, Sapporo, Japan E-mail address: [email protected]
Abstract: Octahedral anatase particles (OAPs) were modified by plasmonic metals to obtain photocatalytic activity under overall solar spectrum for decomposition of both chemical and microbiological pollutants.
1. Introduction Titania is one of the most frequently used semiconductor photocatalysts, due to its high photocatalytic activity, chemical stability, low price and non-toxicity [1]. However, inactivity under visible-light irradiation, which are typical for all wide-band semiconductors, and still low quantum efficiency should be improved for its higher acitivity. Therefore, various studies have been performed to enhance photocatalytic performance of titania, e.g., by morphology improvement using facetted titania [2], doping [3] and surface modification [4]. Recently, we have shown that octahedral anatase particles (OAPs) exhibit enhanced photocatalytic activity, due to possible preferential distribution of shallow than deep electron traps (as shown in Fig. 1, left), and therefore prolonged lifetime of photogenerated electrons without recombination has been observed [5,6]. Moreover, modification of titania with noble-metal nanoparticles (NMNPs) resulted in appearance of photocatalytic activity also under visible range of solar spectrum, owing to its activation by localized surface- plasmon resonance (LSPR) [7]. 2. Results To obtain highly active photocatalysts at overall solar spectrum, the plasmonic photocatalysts, composed of facetted anatase titania (OAPs) and plasmonic nanoparticles such as gold (Au), silver (Ag) and copper (Cu), have been prepared. OAPs were prepared by hydrothermal (HT) process [5,6] and NMNPs were deposited on the surface of OAPs by photodeposition method (Ag/OAPs shown in Fig. 1, center) [8]. Although bare OAPs exhibit high photocatalytic activity under UV irradiation [5,6], they are inactive under visible light irradiation. Modification with NMNPs resulted in significant enhancement of photocatalytic activity under both UV and visible light (Fig. 1, right), suggesting that NMNPs play dual function, i.e., retardation of charge-carrier recombination and photosensitization, respectively. However, ratio of enhancement by NMNP-loading varied depending on used NMNPs and tested systems, e.g., it was observed that deposition of Au resulted in the highest UV-activity for methanol dehydrogenation (H2 system) and visible-light activity for 2-propanol oxidation, while Cu deposits resulted in the highest activity for oxidative decomposition of acetic acid (CO2 system). On the contrary, modification with Ag resulted in the highest antibacterial and antifungal activities, due to both bactericidal properties of Ag and photocatalytic activity induced by NMNP loading.
Fig. 1. (left) Scheme of oxidative decomposition of acetic acid on OAPs, (center) STEM image of NMNP- modified OAPs and (right) Photocatalytic activity of bare and NMNP-modified OAPs under UV and/or visible-light irradiation.
References [1] B. Ohtani, J. Photochem. Photobiol. C-Photochem. Rev. 11, 157-178 (2010). [2] F. Amano, O.-O. Prieto-Mahaney, Y. Terada, T. Yasumoto, T. Shibaya, B. Ohtani, Chem. Mater. 21, 2601-2603 (2009). [3] J. Kuncewicz, B. Ohtani, Chem. Commun. 51, 298-301 (2015). [4] E. Kowalska, H. Remita, C. Justin- Colbeau, J. Hupka, J. Belloni, J. Phys. Chem. C. 112(4), 1124-1131 (2008). [5] Z. Wei, E. Kowalska, B. Ohtani, Chem. Lett. 43, 346-348 (2014). [6] Z. Wei, E. Kowalska, J. Verrett, C. Colbeau-Justin, H. Remita, B. Ohtani, Nanoscale 7, 12392-12404 (2015). [7] E. Kowalska, R. Abe, B. Ohtani, Chem. Commun. 2, 241-243 (2009). [8] E. Kowalska, Z. Wei, B. Karabiyik, M. Janczarek, A. Markowska-Szczupak, B. Ohtani, Adv. Sci. Technol. 93, 174-183 (2014).
271 P-05-05
InfluenceIfl of platinum-loading on photocatalytic activities of particles separated from an anatase-rutile mixed titania
Kunlei Wang,1 Bunsho Ohtani,1,2 Ewa Kowalska1,2 1Graduate School of Environmental Science and 2Institute for Catalysis, Hokkaido University E-mail address: [email protected]
Abstract: Isolated crystalline phases of anatase and rutile were successfully obtained from homogenized sample of Evonik (Degussa) P25. Action spectrum analyses for methanol dehydrogenation indicate that preferential platinization of rutile and aggregation of titania particles during thermal post-treatment are responsible for enhanced photocatalytic activities.
1. Introduction It is well known that Evonik P25 titania (P25), used widely as a highly efficient photocatalyst, contains both anatase and rutile crystallites [1]. In our previous studies, anatase and rutile particles were isolated from P25 by selective chemical dissolution procedures using ammonia-hydrogen peroxide and diluted hydrofluoric acid, respectively [1,2]. In the present study, post-treatment operations, such as thermal treatment and washing with an alkali solution have been applied for sample purification (ANA, RUT) [3]. To minimize heterogeneity of P25, an original sample was homogenized by suspending in water, centrifugation and freeze drying (Homo-P25). Photocatalytic activity was evaluated for methanol (50vol% in water) dehydrogenation under irradiation by a mercury lamp (> 290 nm) at 298 K in the presence of various concentrations of chloroplatinic acid for in-situ platinum (Pt) photodeposition (0.005–2.0wt%). 2. Results Modification of titania with Pt nanoparticles resulted in significant enhancement of photocatalytic activity, due to co-catalytic nature of Pt, on which proton reduction by photoexcited electrons occurs. It was found that the rate of hydrogen liberation increased with Pt-loading reaching plateau at different amount of deposited Pt, depending strongly on titania samples in UV–visible photoirradiation, as shown in Fig. 1a. Platinized RUT exhibited photocatalytic activity higher than the other platinized samples, i.e., ANA, Homo- P25, Homo-P25-200 (Homo-P25 heated at 473 K), even with lower amount of deposited Pt. This is possibly due to interparticle electron transfer in secondary particles (Fig. 1c) aggregated in the heat-treatment process of isolations to result in decrease in number of Pt deposits required for activation of Pt for hydrogen evolution. Comparison of action spectra (Fig. 1b) suggested that for a mixed titania photocatalysts (Homo-P25), Pt is deposited predominantly on rutile particles and its lower photocatalytic activity in the relatively low Pt loading (Fig. 1a) is attributable to the lower content (ca. 15%) of rutile in Homo-P25. Moreover, modification of titania with Pt resulted in appearance of photocatalytic activity under visible- light irradiation for oxidation of 2-propanol via surface-plasmon resonance absorption of Pt. Correlation between properties and photocatalytic activities under both UV and visible-light irradiation is discussed.
0.9 (a)ġ (b)ġ 100 100 (c) 0.8 HomoP25(0.2) ANA(0.2) RUT Homo-P25-200 0.7 80 RUT(0.2) 80 0.6 ANA ANA(A) RUT(R) 0.5 60 60 isolated-rutile R in (R+A)
0.4
(%) 40 40 liberation (mmol/h)
2 0.3 isolated-anatase
0.2 intensity 20 20
homo-P25 (%) 100-reflectance 0.1 Homo-P25 10 20 30 40 50 60 70 80 90 rate of H 0.0 2 (degree) 0 0 0.0 0.5 1.0 1.5 2.0 apparent quantum efficiency 340 360 380 400 420 440 amount of platinum-loading (wt%) wavelength (nm)
Fig. 1 (a) Influence of platinum amount on rate of H2 liberation (insert: XRD patterns of P25, isolated anatase and rutile); (b) Quantum yield of methanol dehydrogenation on samples. Absorption spectra of samples and subtraction of anatase from rutile; (c) Schematic view of aggregated Pt-loaded titania. References [1] B. Ohtani, O.-O. P.-Mahaney, D. Li, and R. Abe, J. Photochem. Photobiol. A Chem. 216, 179-182 (2010). [2] B. Ohtani, Y. Azuma, D. Li, T. Ihara, R. Abe, Trans. Mater. Res. Soc 32, 401-404 (2007). [3] A. Markowska-Szczupak, K. Wang, P. Rokicka, M. Endo, Z. Wei, B. Ohtani, A.W. Morawski, E. Kowalska, J. Photochem. Photobiol. B 151, 54-62 (2015).
272 P-06-01
Phase retrieval approach based on transport of theh intensity equation by using microscope coverslips
Hsin-Feng Hsu, Hou-Ren Chen, Chyong-Hua Chen, and Wen-Feng Hsieh Department of Photonics and Institute of Electro-Optical Engineering, National Chiao Tung University, Hsinchu 300, Taiwan wfhsieh@ mail.nctu.edu.tw
Abstract: We present a simple phase retrieval method based on the transport of the intensity equations by insertion different several glass coverslips in between the objects and the camera and obtaining several object field intensities without moving the camera or objects. The experimental results show that this approach provides a simple and inexpensive way to retrieve the phase image.
IJįġIntroduction Phase imaging is important in wide applications, such as biological studies of cells and electron microscopy because many samples are nearly invisible in their intensity distributions, but exhibit strong phase contrast. Besides, these phase images have better resolutions and some might reach their imaging resolution beyond the resolution of Rayleigh’s criterion. The transport of intensity equation (TIE) experimentally offers one of phase from intensity techniques for computing phase quantitatively from several intensity distributions. However, TIE requires at least two images at multiple axially displaced planes, and then physical moving parts are required. Recently, several schemes including volume holography [1], chromatic aberrations [2], spatial light modulator [3], flow cytometry [4] and electrically tuning lens [5] were presented to avoid the mechanical motion to acquire the intensity stack. However, these approaches either have complicated image systems or are available specifically for the non-adherent cells. In this paper, we present a simple imaging acquisition system by inserting several microscope coverslips in between the camera and objects and reconstruct the phase images by the TIE. 2. Experiment Figure 1 shows the experimental apparatus for the proposed imaging acquisition system. A red light LED is the light source, and a dragonfly wing is the test sample. Its optical image is displayed in Fig. 2 (a). An optical lens produces an image and the CCD camera is put at the image plane of the system. Firstly, one microscope coverslip is inserted behind the lens, and then the camera records the first intensity image. Then the 2nd microscope coverslip is put behind the first one, and then the camera captures the 2nd intensity image. We apply the TIE solver with these two intensity images and obtain the corresponding phase image, as shown in Fig. 2(b). The calculated phase image is in a close agreement with the captured optical image.
Fig. 1. Experimental system. Fig. 2. (a) Optical image of dragonfly wing and (b) recovered phase image by a TIE solver. 3. Summary Here, we proposed a new imaging acquisition system based on TIE by introducing microscope coverslips. This approach doesn’t need to move the camera or the object. By inserting several coverslips, we can obtain the intensity stack with different focus positions. Experimental results shows the calculated phase image agrees well with the object. 4. Acknowledgement This work was supported by Ministry of Science and Technology of Taiwan under contract MOST 102- 2221-E-009-178-MY3 and MOST 102-2221-M-009-016-MY3. 5. References [1] L. Waller, Y. Luo, S. Y. Yang, and G. Barbastathis, Opt. Lett. 35(17), 2961-2963 (2010). [2] L. Waller, S. S. Kou, C. J. R. Sheppard, and G. Barbastathis, Opt. Exp. 18(22), 22817-22825 (2010). [3] P. F. Almoro, L. Waller, M. Agour, C. Falldorf, G. Pedrini, W. Osten, and S. G. Hanson, Opt. Exp. 37(11), 2088-2090 (2012). [4] S. S. Gorthi and E. Schonbrun, Opt. Lett. 37(4), 707-709 (2012). [5] C. Zuo, Q. Chen, W. Qu, and A. Asundi, Opt. Exp. 21(20), 24060-24075 (2013).
273 P-07-01
SensitiveS Detection of Small Particles in Fluids Using Optical Fiber Tip with Dielectrophoresis
Yi-Hsin Tai and Pei-Kuen Wei Research Center for Applied Sciences, Academia Sinica, Taipei, 11529, Taiwan. [email protected]
Abstract: This work presents using a tapered fiber tip coated with thin metallic film to detect water quality with very high sensitivity. When an AC voltage applied to the Ti/Al coated fiber tip and ITO substrate, a gradient electric field at the fiber tip induced attractive/repulsive force to suspended small particles due to the frequency-dependent dielectrophoresis (DEP) effect. Such DEP force greatly enhanced the concentration of the small particles near the tip. The increase of the local concentration also increased the scattering of surface plasmon wave near the fiber tip. Combined both DEP effect and scattering optical near-field, we show the detection limit of the concentration for 1.36 m polystyrene beads can be down to 1 particles/mL. The detection limit of the Escherichia coli (E. coli) bacteria was 20 CFU/mL. The fiber tip sensor takes advantages of ultrasmall volume, label-free and simple detection system.
1. Introduction Polluted drinking water could contain numerous of submicron/micron particles even though it looks crystal clear. Some of these small particles, such as bacteria, could cause serious illnesses to human body such as gastrointestinal infective disease, fever, or dehydration [1-3]. Therefore, the fast and sensitive detection of small particles in fluids is important for monitoring the quality of drinking water. There are many methods for detecting small bacteria in water [4, 5]. Most of them are based on the immunoassay techniques. However the immunoassay method needs antibody, chemicals and labels. It needs many steps and takes hours for the detections. On the other hand, optically label-free technologies are simple, real-time and cost-effective. Some methods such as Bragg grating on periodic surface structure [6, 7], surface plasmon resonance on gold surface have been demonstrated for the label-free detection of bacteria [8, 9]. In this work, we present an ultrasensitive detection method for detecting small particles in water by using a tapered optical fiber tip coated with a thin metallic film. The tapered fiber tip has a low transmission background with strong evanescent wave near the tip region due to the generation of surface plasmon wave. The scattering of the surface plasmon wave by small particles produces significant scattering near-field photons. The metal coated fiber tip also acts as a tip electrode. Combining it with a transparent electrode substrate, such as ITO glass, a dielectrophoresis (DEP) force can be induced. By inputting a suitable alternating current (AC) frequency to the electrode, the DEP force helps concentrating the submicron/micron particles near the tip in a short time. The fiber tip can easily detect those particles because of the strong scattering of the surface plasmon wave. We show the detection limit by the DEP concentration can be down to 1 particles/mL for 1.36 m polystyrene beads and less than 20 CFU/mL for Escherichia coli (E. coli) bacteria. The detection time is less than 10 minutes.
Fig. 2.(a) The measured intensity as a function of time for different concentration of E. coli. Different concentration of E. coli bacteria can be clearly discriminated less than 10 minutes. (b) The measured intensity vs. Fig. 1 (a) The illustration of the detection principle. (b), The the E. coli concentration at the saturation condition. The inset shows the calculated optical fields without and with a micron sphere at measured noise level for low concentration of E. coli. the tip. The diameter of the sphere is 0.4 ͔m
274 P-07-02
Visualization of Pesticides Using Enhanced Surface Plasmon Resonances in Capped Silver Nanoslits
Meng-Lin You, Kuang-Li Lee and Pei-Kuen Wei Research Center for Applied Sciences, Academia Sinica, Taipei, 11529, Taiwan. [email protected]
Abstract: We combined an indirect competitive immunoassay, capped-nanoslit-based surface plasmon resonance biochip with a simple portable imaging setup for label-free detection of imidacloprid pesticides. The biochip consists of several capped nanoslit arrays with different periods. The qualitative and semi-quantitative analyses of the analyte can be conducted by observing the spot shift on the chip. The precise quantitative analysis can be further completed by using image processing in a smartphone. The experimental results show that the biochips simultaneously detected four different concentrations of imidacloprid pesticides and the visual detection limit is about 1 ppb, which is below the maximum residue concentration permitted by law (20 ppb). Such a portable sensing platform possesses several advantages, including high-throughput detection, quantitative and qualitative analysis, rapid determinations, user-friendliness and low cost.
1. Introduction to main text format and page layout In order to fulfill the requirement of rapid, simple, selective and sensitive detection, enzyme-linked immunosorbent assays (ELISAs) have been developed for detection of neonicotinoids in different matrices. However, repeated washing steps make the ELISA method difficult for one-step high-throughput assay. Different from the previous techniques requiring the assistance of labels, In this study, we combined an indirect competitive immunoassay, capped-nanoslit-based SPR biochip and simple portable spectral imaging system for label-free detection of imidacloprid pesticides. The sensing chip, similar to a tiny spectral analyzer, consists of several capped nanoslit arrays with different periods. The distribution of the transmitted light from these arrays comprises a spectral image on the chip. The detection system is a smartphone with a light-emitting diode (LED) light source and laser-line filter. When biomolecules adsorb on the surface of the chip, the brightest spot of the spectral image is shifted. The qualitative and semi-quantitative analyses of the analyte can be conducted by observing the spot shift on the chip. The experimental results show that the biochips can simultaneously detect four different concentrations of imidacloprid pesticides and 1 ppb and 10 ppm imidacloprid pesticides result in 80% and 20% wavelength shifts, respectively. The visual detection limit is about 1 ppb, which is below the maximum residue concentration permitted by law (20 ppb). The lowest detectable concentration for the imidacloprid pesticide can be further improved by using image processing in the smartphone. Such a portable sensing platform possesses advantages of high-throughput detection, quantitative and qualitative analysis, rapid determinations, user-friendliness and low cost. It can be utilized for on-site screening of pesticides and considered as a cost-effective complement technique to the chromatography methods.
Fig. 1. An indirect competitive immunoassay for label-free detection of imidacloprid pesticides using plasmonic chips and the imaging system. (a) Schematic representation of a competitive immunoassay for label-free detection of imidacloprid pesticides using plasmonic biochips and the spectral imaging system. (b) The spectral images of the chip for different surface conditions. The chose period of the capped nanostructure ranged from 471 to 525 nm. The period difference was 3 nm. (c) The intensity distributions of the spectral images in panel (b) for different surface conditions. (d) The position of the brightest zone of the spectral image against the surface condition. The brightest spot shifted to right with the decrease of the concentration of the imidacloprid pesticide. 2. References [1] K.L. Lee, M-L You, C-H Tsai, E-H Lin, S-Y Hsieh, M-H Ho, J-C Hsu, P-K Wei, ”Nanoplasmonic biochips for rapid label-free detection of imidacloprid pesticides with a smartphone” Biosensors and Bioelectronics, 75, 88-95 (2016) [2] K. L. Lee, J. B. Huang, J. W. Chang, S. H. Wu, P. K. Wei, "Ultrasensitive Biosensors Using Enhanced Fano Resonances in Capped Gold Nanoslit Arrays", Sci. Rep. 2015, 5, 8547.
275 P-07-03
NovelN Photothermal Spectroscopy using Plasmonic Metamaterials for Detection in Nanofluidics
Thu H. H. Le1), Yukie Yokota2), Tanaka Takuo1,2) Innovative Photon Manipulation Research Team, RIKEN Center of Advanced Photonics, Japan Metamaterials Laboratory, RIKEN, Japan E-mail address: [email protected]
Abstract: This study reports a novel photothermal spectroscopy for ultra-sensitive and label- free detection of molecules using plasmonic metamaterials. Its principle is based on the detection of subtile local change in the temperature as molecules absorbs light, while plasmonic nanotrustures are introduced for efficient absorption enhancement. This method has important implications on detection in ultra-small spaces of micro/nanofluidic devices.
1. Introduction Recently micro and nanofluidic systems have attracted much attention as ideal platforms for breakthrough bioanalytical tools. The interest in micro/nanofluidics has resulted in a high demand of non-label detection techniques in ultra-small volume (aL-fL).[1] Among existing optical detection methods in micro/nanofluidics, photothermal spectroscopy (PTS) is an important approach as it allows the detection of non-fluorescent molecules in a non-label fashion. Its principle is based on the detection of refractive index change following the thermal relaxation when molecules absorb light. Many types of PTS has been developed for microfluidics that show prominent detectability in microscale spaces[2]. However, sensitivity of PTS becomes an issue in sub-micrometer spaces where thermal diffusion is dominant. In this study, we propose an idea of exploiting the field enhancement effect in plasmonic metamaterials to improve the sensitivity of PTS, and realize the PTS detection in sub-micrometer spaces. The principle is shown in figure 1(a). Metal nanostructures whose plasmonic resonance is matched with the absorption of target molecules are designed and integrated inside fluidic channels. As the device is irradiated with excitation light, the absorption of light results in Figure 1 (a) Principle and (b) PTS signal generation the generation of thermal, following the subtle change of refractive index in the surroundings, which is sensitively probed by the probe beam. The quantitative measurement of thermal allows us to determine the exact number of excited molecules. 2. Experimental results Channels with depth of ~800 nm was fabricated on BK7 glass substrate. Aluminium nanodot structures were fabricated inside the channels by top-down fabrication. Diameter of nanodots were designed to be ~150 nm to achieve the plasmonic resonance at 532 nm. This substrate was then bonded with another cover glass substrate to obtain a sealed fluidic device. 532 nm laser (0.83 mW) and 633 nm laser were used as excitation and probe beams respectively and they were collimated into a microscope through a 20x objective lens. Acid Red I with the absorption peak at the excitation wavelength was introduced into the fluidic device as analyte solution. The excitation beam is intensity modulation at 1.0 kHz, and the change in probe beam intensity during the excitation is probed through a lock-in amplifier. Figure 1(b) shows the detected photothermal signal when water (dashed line) and 2.5mM solution of Acid Red I (solid line) were introduced into the channels. The clear difference between two signals verify the photothermal signals from the absorption of analyte itself, while the signal in case of water only can be attributed to the absorption of aluminum nanodots. The detection volume is 1.3 fL, therefore the number of detected molecules can be estimated to be attomole level. 3. Conclusion We have demonstrated an ultra-senstive detection of non-fluorescent molecules in sub-micrometer spaces by utilizing the plasmonic nanostructures. Although the strong absorption of plasmon itself is still an obstacle (high background) in this detection, the manipulation of optical properties of nanostructures to suppress this background is expected to improve the detection limit. From the practical viewpoint, our result promises an important impact in label-free bioanalysis, especially single cell analysis using nanofluidic devices.
[1] T. Kitamori et al., Chem. Soc. Rev. 39, 1000-1013 (2010) [2] T. Kitamori et al., Ana. Chem. 82, 9802-9806 (2010)
276 P-07-04
Rapid nanoimprinting method for manufacturing highi h sensitivity surface plasmon resonance sensor
Huai-Yi Chena,b,c,Pei-Kuen Weia,d,e and Ji-Yen Chenga,d,f a Research Center for Applied Sciences, Academia Sinica, Taiwan b Department of Engineering and System Science, National Tsing Hua University,Taiwan c Nano Science and Technology Program, Taiwan International Graduate Program, Academia Sinica and National Tsing Hua University, Taiwan. d Institute of Biophotonic, National Yang-Ming University, Taiwan e Department of Optoelectronics, National Taiwan Ocean University, Taiwan f Department of Mechanical and Mechantronic Engineering, National Taiwan Ocean University, Taiwan Corresponding author’s E-mail: [email protected]
Abstract: Plasmonic sensors such as surface plasmon resonance (SPR) sensor are widely used for study real-time biomolecular interactions. Nanostructure-based SPR sensors made by nanoimprinting provide high sensitive and label-free detection with low cost [1]. These nano-plasmonic sensors can also be applied for clinical samples [2]. However, conventional nanoimprinting is a time consuming process and not suitable for mass production. Here, we proposed a rapid method for fabricating nanostructure array. By re-designing the nanoimprinting procedure and building a new imprinting machine with a non-contact infrared heater, we can significantly reduce the nanoimprinting time and obtain high sensitive SPR sensor.
Fig. 1. SEM image of imprinted nanoslit structure on plastic film
References [1] Kuang-Li Lee, Jhih-Bin Huang, Jhih-Wei Chang, Shu-Han Wu and Pei-Kuen Wei. Scientific Reports. 5,8547 (2015). A Mater. Sci. Process. 107, 23-30 (2012). [2] Mansoureh Z. Mousavi, Huai-Yi Chen, Kuang-Li Lee, Heng Lin, Hsi-Hsien Chen, Yuh-Feng Lin, Chung- Shun Wong, Hsiao Fen Li, Pei-Kuen Weia and Ji-Yen Cheng. ANALYST, 140, 4097-4104 (2015).
277 P-07-05
HighHi Sensitivity Oval-Shape Localized Surface Plasmon Resonance Biosensor for A549 Cancer Cell Label-Free Detection
Shih-Wei Huang, 1 Wei-Chun Hung,1 Hsiang-Yu Chou,1 Yi-Chun Yang,1 Chien-Chung Peng1, Hsiang- Ming Yu,1,2 Cheng-Wen Chen,1 Mohammed Nadhim Abbas,1 Min-Hsiung Shih1,2,3*, Yi-Chung Tung1, and Yia-Chung Chang1,2 1Research Center for Applied Sciences, Academia Sinica, Taipei 11529, Taiwan 2Department of Photonics, National Chiao-Tung University, Hsinchu 30010, Taiwan 3Department of Photonics, National Sun Yat-sen University, Kaohsiung 804, Taiwan [email protected]
Abstract: Cell detection usually requires the extensive sample labeling process, therefore recently the label-free detection with localized surface plasmon resonance (LSPR) devices receive huge attention recently. And circular nanodisk also have specifi characteristic of wide angle detection. However, due to the small index contract, it is difficult to distinguish the cells from the buffered liquid medium with the LSPR devices with a low sensitivity. In this study, a bilayer oval nanodisk localized surface plasmon resonance (LSPR) index sensor was designed and demonstrated for label- free A549 cancer cell detection. By optimizing the spatial overlap of the resonant mode and the sensing environment, a high sensitivity of 1460 nm/RIU and a high figure of merit of 14.6 were achieved. The absorptivity of the index sensor is sensitive to small local refractive index changes that occur after A549 human lung cancer cells are seeded in the phosphate-buffered saline solvent. This high-sensitivity optical biosensor platform realizes a real-time, noninvasive cell detection method.
The optical fields of SPPs/LSPPs are highly sensitive to local changes in the refractive index, miniaturized surface-plasmon-resonance-based devices have been used in environmental detection [1], biomedical diagnostics [2], and food safety monitoring. In this study, we present an oval disk (OD) LSPR structure as a sensitive plasmonic refractive index sensor. A metal–dielectric–metal structure is applied to render the device a wide-angle perfect absorber [3] that acquires stronger signals. Thus, this plasmonic OD is a highly feasible biosensing candidate for monitoring the refractive index change caused by surrounding cells.
Fig1. (j
(k
Figure 1. Schemata of CD (a), OD (d), and BOD (g). Top (b) and side views (c) of the simulated |Hy|2 field of a CD. (e) TM mode of the simulated |Hy|2 field of an OD. (f) Cross section along the short axis of the OD |Hy|2 field. (h) TM mode of the simulated |Hy|2 field of a BOD. (i) Side view of the simulated |Hy|2 field of a BOD. (j) Wavelength shift versus RI of the three index sensors s simulated using COMSOL. (k) OM images of the sample dipped in PBS+ (bottom) and the biosensor array capped with A549 cells. Absorptivity of the biosensor in PBS+ (blue) and after being capped with A549 cells (red).
[1] J. Ji, J. A. Schanzle, and M. B. Tabacco, "Real-Time Detection of Bacterial Contamination in Dynamic Aqueous Environments Using Optical Sensors," Analytical chemistry 76, 1411-1418 (2004). [2] C. R. Yonzon, C. L. Haynes, X. Zhang, J. T. Walsh, and R. P. Van Duyne, "A Glucose Biosensor Based on Surface-Enhanced Raman Scattering: Improved Partition Layer, Temporal Stability, Reversibility, and Resistance to Serum Protein Interference," Analytical chemistry 76, 78-85 (2003). [3] N. Liu, M. Mesch, T. Weiss, M. Hentschel, and H. Giessen, "Infrared perfect absorber and its application as plasmonic sensor," Nano letters 10, 2342-2348 (2010).
278 P-07-06
Comparison of Si photodetectors with dense graphene oxide of different oxidation levels
Ching-Kuei Shih, Yu-Tang Ciou, Chun-Wei Chiu, Yen-Chun Chen, and Chu-Hsuan Lin* Department of Opto-Electronic Engineering, National Dong Hwa University E-mail address: [email protected]
Abstract: We have tuned the oxidation levels of graphene oxide via modifying the usage of H2O2. Graphene oxide can be applied to demonstrate Si photodetectors. The influence of oxidation levels is comprehensively compared for p-type and n-type Si photodetectors.
1. Introduction Graphene and graphene oxide (or called graphite oxide) have been utilized to demonstrate field effect transistors [1]. Some study has also shown that GO can be used in the nonvolatile memory as the insulation film [2]. Whatever for field effect transistors or memories, the high resistance of GO is needed to lower the leakage of these devices. The increase on the thickness of GO via multi-layer deposition may increase the resistance, but it would not be two-dimensional structure anymore. We try to broke bonds as much as possible via the higher level of oxidation and expect the resistance can be increased and the band gap of graphene oxide can be increased. We would like to compare their influence on p-type and n-type Si photodetectors. 2. Experiment We prepared the powder of graphite oxide by the modified Hummers method [3]. The key point to tune the oxidation levels is via changing the usage amount of hydrogen peroxide (H2O2). H2O2 (35%) was added with volumes of approximately 1 % and 4 % of solutions. The corresponding solutions were used to prepare samples named as GO1 and GO4, respectively. In order to uniformly deposit these hydrophilic GO flakes on Si substrates, Si substrates were immersed in the SC1 solution [4]. The GO suspension was then dropped both on p-type and n-type Si substrates to form the GO insulator films. The small circular Al gate was evaporated on the top of the Si substrate, and large-area Al was also evaporated on the back side of Si to form ohmic contacts. 3. Results and discussion X-ray photoelectron spectroscopy (XPS) could provide direct evidence to prove that the difference in H2O2 treatment indeed results in difference in oxygen content, and the content of oxygen in GO4 is indeed higher (Fig. 1). We find that the inversion photocurrent of p-Si photodetectors with higher oxidation levels is larger, but the dark inversion current is less sensitive to the oxidation levels. The accumulation dark currents of p-Si photodetectors also significantly decrease with oxidation levels. On the other hand, the cases for n-Si photodetectors are different. The corresponding band diagrams will be compared to explain the detailed mechanism in this conference. 4. Conclusion The implementation of GO with different oxidation levels in Si photodetectors proves that the modulation for both the photocurrents and dark currents can be demonstrated. Its impact on p-type and n-type photodetectors is different.
GO1 GO4 fitting peaks fitting peaks C-C C-C C-O C-O
O=C-OH O=C-OH Intensity (a.u.) Intensity (a.u.)
280 282 284 286 288 290 292 280 282 284 286 288 290 292 Binging Energy (eV) Binging Energy (eV) Fig. 1. The C1s XPS results of (a) GO1 and (b) GO4. The ratio of XPS intensity of C-O (at 286.5 eV) to C-C (at 284.5 eV) of GO4 is larger than that of GO1.
[1] B. Standley, A. Mendez, E. Schmidgall, and M. Bockrath, Nano Lett. 12, pp. 1165-1169 (2012). [2] H.Y. Jeong et al., Nano Lett.10, pp. 4381-4386 (2010). [3] C.-H. Lin, W.-T. Yeh, C.-H. Chan, and C.-C. Lin, Nanoscale Res. Lett. 7, p. 343(2012). [4] Chu-Hsuan Lin, Wei-Ting Yeh, Mei-Hsin Chen IEEE J. Sel. Top. Quantum Electron. 20, p. 3800105 (2014).
279 P-07-07
Surface-enhancedSf Raman scattering detection of amyloid- peptides using an electrode nanogap enabled device
Katrin Vu1,2,3, Leonardo Lesser-Rojas4,5, Chun-Yu Chen6, Yun-Ru Chen6 and Chia-Fu Chou3,7* 1Nanoscience and Technology Program, Taiwan International Graduate Program, Academia Sinica, Taipei, Taiwan 2Department of Engineering and System Science, National Tsing Hua University, Hsinchu, Taiwan 3Institute of Physics, Academia Sinica, Taipei, Taiwan 4Research Center for Atomic, Nuclear and Molecular Sciences, San Pedro de Montes de Oca, San Jose, Costa Rica 5School of Physics, University of Costa Rica, San Pedro de Montes de Oca, San Jose, Costa Rica 6Genomics Research Center, Academia Sinica, Taipei 11529, Taiwan 7Research Center for Applied Sciences, Academia Sinica, Taipei, Taiwan *E-mail: [email protected]
Abstract: Although the peptide Amyloid- (A ) is found to be directly involved in the Alzheimer’s disease (AD) and its aggregative ability being closely related to its neurotoxicity, the precise mechanism of the neurotoxic effects of amyloid- remains unclear. It is believed in recent studies that the key determinant for the neurotoxicity of A is the specific conformation of the oligomeric species, therefore the structural analysis of A is one of the most promising ways of revealing the mechanism of AD. In this work, A peptides were trapped using an electrode nanogap enabled dielectrophoretic device (5-15 nm gap between Au/Ti electrodes on a 7mm x 7mm silicon chip) and detected with surface-enhanced Raman spectroscopy at the hotspot in the interelectrode space. Fluorescence observation of the accumulation of thioflavinT-labelled A oligomers at the nanogap between electrodes provided evidence of the trapping. In addition, the trapping event was monitored with nanoelectronic current measurements confirming the presence of the molecules in the vicinity of the gap. SERS spectra of A monomers, oligomers and fibrils show the structural conformation of different stages of protein aggregation. Here, we demonstrate how our platform, which combines dielectrophoretic trapping of molecules with simultaneous electronic and spectroscopic measurements of a low- copy number of peptides, is able to observe A in different conformational states, showing the transition of random coil/ -helical structured monomers to -sheet rich fibrils. Our device can probe peptides in solution without further modification, preserving their natural state and bioactivity. Therefore, it represents a valuable tool for detection and structure determination of A associated with the progression of Alzheimer’s disease.
280 P-07-08
Determination of the effective index and thickness off biomolecular layer using gold nanogrid array
Ming-Yang Pan and Pei-Kuen Wei Research Center for Applied Sciences, Academia Sinica, Taipei, 11529, Taiwan. [email protected]
Abstract: We present an accurate method to determine the effectiverefractive index and thickness of biomolecular layer by using Fano resonance modes in dual-period gold nanogrid arrays. The effective refractive index changes along the x and y directions are simultaneously measured and obtained by using a modified dispersion relation. The thickness of the surface layer is calculated by a three-layer waveguide equation without any fitting parameters. The accuracy of the proposed method is verified by comparing the results with the known coated dielectric layer and self-assembly layers. The applications of this method and nanogrid chips for determining the thickness and surface concentration of antigen/antibody interactions are demonstrated.
1. Introduction to main text format and page layout Surface plasmon resonance (SPR) has been widely used in applications of biomedical sensors, food safety and environmental pollution monitoring. The label-free, real-time detection and high surface sensitivity make SPR become more popular in measuring biomolecular and chemistry interactions. The signal of SPR wavevector comes from the change of surface molecular density and thickness due to biomolecular binding, protein dissociation, and cell metabolism. However, the commonly used SPR methods can only measure the refractive index change, which is the average contribution of the molecular density and its corresponding thickness. Because most of biomolecular layer is much smaller than the evanescent length of SPR wave, there is no direct information of the film thickness. In comparison to refractive index, the surface thickness is an important parameter that represents the coverage of molecular, adsorption processes or concentration of analyte. There were several works demonstrating the thickness determination based on conventional prism- based SPR techniques. However, these methods are complicated in optical configuration and have a limited linear response range of SPR signals. In this paper, we present a dual-mode SPR methods based on gold nanogrid arrays with two different periods. The non-polarized transmission light from the two-period nanogrids shows two distinct Fano resonant modes. Both modes have different responses to the surface density and thickness. We developed a guiding mode equation with a modified dispersion relation to analyze the two Fano resonance signals. The proposed nanostructures and calculations match quite well with the known surface coating materials and ellipsometric measurements. Finally, the determination of thickness and surface concentration of the antibody-antigen interaction as a function of concentration is demonstrated.
Fig. 1. (a) A schematic configuration of transmission spectrum measurement. (b) The measuredtransmission spectrum of 680 × 810nm nanogrid structure for unpolarized light. (c) PEI/PAA films. White arrows indicate the red shifted resonance peaks of x and y-resonances. (d) The calculated thicknesses by previous BSM method (blue-squares) and our WEM method (red-cycles) for different bilayer numbers. References [1] Ming-Yang Pan, Kuang-Li Lee, T Wan-Shao Tsai, Likarn Wang, Pei-Kuen Wei, “Determination of the effective index and thickness of biomolecular layer by Fano resonances in gold nanogrid array”, Optics Express 23(17) 21596-21606 (2015)-21606 (2015) [2] K. L. Lee, J. B. Huang, J. W. Chang, S. H. Wu, P. K. Wei, "Ultrasensitive Biosensors Using Enhanced Fano Resonances in Capped Gold Nanoslit Arrays", Sci. Rep. 2015, 5, 8547.
281 P-07-09
AgA Nanowire Immobilized on Gold Substrate by SAM for Surface Enhanced Raman Spectroscopy
Shao-Chieh Chen and Kotaro Kajikawa Interdisciplinary Graduate School of Science and Engineering, Tokyo Institute of Technology, Yokohama 226-8502, Japan E-mail address: [email protected]
Abstract: A simple and inexpensive way for making surface enhanced Raman spectroscopy substrate has been reported. Ag nanowires are immobilized on a gold substrate using 11- aminoundecanethiol self-assembled monolayers.
1. Introduction Ag nanowires (AgNWs) are promising plasmonic materials. We successfully immobilized the AgNWs on a gold substrate to enhance the plasmonic resonance for surface-enhanced Raman spectroscopy (SERS). The immobilization was made by use of 11-aminoundecanethiol (AUT) self-assembled monolayers (SAMs). The AgNW-immobilized substrate can be used for highly sensitive SERS measurements. 2. Experiments A 50nm-thick gold thin film has been vacuum-evaporated by on a cleaned glass substrate. The AUT was dissolved in ethanol at 0.1 mM. The substrate was immersed in the AUT solution for 120 min. After forming an AUT SAM, the gold substrate was rinsed by ethanol to remove excess AUT molecules, and dried it in air. To immobilize the AgNWs on the substrates, the substrate was immersed in the AgNWs solution for about 90 min and rinsed by ultra pure water. The AgNW solution was diluted by 1/10 by ultra pure water. We call this as an AgNWs-Au substrate. 3. Results and Discussion The AgNWs-Au substrate has silver color, as shown in Fig. 1(a). We measured absorption spectra using a U-2180 spectrometer (Hitachi). The reference was a 50nm-thick Au substrate. The sample has a peak at 380nm, which is consistent with the literature [3]. In the SERS experiments, Rhodamine 6G (R6G, 20uM) was adsorbed on the AgNWs-Au substrate. The Raman spectra of both Au and AgNWs-Au substrates are shown in Fig. 1(b). Clear Raman peaks are observed in the AgNWs-Au substrate. In contrast, there is no SERS signal from the Au substrate without AgNWs, instead of existence of R6G molecules. The result revealed the sample could be used as highly sensitive SERS substrate. 4. Conclusion We have shown a simple and inexpensive method for depositing AgNWs using AUT SAMs. The AgNWs-Au substrate can be used for highly sensitive SERS. (a) (b)
Fig.1 (a) AgNWs-Au substrate (b) Raman spectrum of R6G on Au and AgNWs-Au substrates.
[1] L. Pan, Y. Huang, Y. Young, W. Xiong, G. Chen, X. Su, H. Wei, S. Wang, and W. Wen, Sci. Rep. 5, 17223(2015). [2] C. Chen, J. Hao, L. Zhu, Y. Yao, X. Meng, W. Weimer and QK. Wang, J. Mater. Chem. A, 1, 13496- 13501(2013) [3] Y.Bi, H. Hu and G. Lu, Chem. Commun., 46, 598-600(2010)
282 P-07-10
Plasmonic Crystal Cavities on Single-Mode Optical FFiberib End-Facets for Label-Free Biosensing
Xiaolong He1, Jie Yang1, Xin Zhou1, Yalin Wang2 and Tian Yang1 1State Key Laboratory of Advanced Optical Communication Systems and Networks, Key Laboratory for Thin Film and Microfabrication of the Ministry of Education, UM-SJTU Joint Institute, Shanghai Jiao Tong University, Shanghai 200240, China. 2Xu Yuan Biotechnology Company, 1883 South Huicheng Road, Shanghai 201821, China E-mail address: [email protected]
Abstract: Plasmonic crystal cavities on bare single-mode fiber end-facets show a steep resonance near the bandedge, a greatly improved figure-of-merit for label-free sensing, and high performance monitoring of biomolecules’ kinetic processes.
Integrating surface plasmon resonance (SPR) structures onto the end-facets of optical fibers to achieve low cost, flexible, in vivo and high throughput label-free biosensing devices has a great potential to open up a variety of new applications [1,2]. However, such devices have been severely limited by spectral broadening due to fiber guided mode diffraction, and have been more applicable to surface enhanced Raman spectroscopy applications [3,4]. Here we report a plasmonic crystal cavity on a single-mode fiber’s (SMF) end-facet [5]. This device shows a steep resonance near the plasmonic bandedge, a refractive index sensitivity over SPR bandwidth figure-of-merit (FOM) that is around twenty times improvement compared with previous reports, and a detection limit (DL) that is nearly as good as planewave coupled SPR. The plasmonic crystal cavity consists of two square arrays of 50 nm wide nanoslits in a 55nm thin gold film, as in Fig. 1(a). The array in the center has a period of 645nm, which couples the SMF guided mode to surface plasmon polaritons (SPP). Its 2nd order spatial Fourier component produces a bandgap for the coupled SPPs, where near the bandedge there is a higher density of SPP states (not shown). The surrounding array has a period of 315 nm, which confines the SPPs within the cavity by Bragg reflection. The interference between the central and surrounding arrays has been optimized. Device fabrication was done by transferring the nanostructured gold film from a quartz substrate onto the fiber end-facet by a “glue-and-strip” method [6]. By immersing the fiber end-facet sensor into different liquids, as in Fig. 1(b), the device shows a quality factor around 100, a sensitivity of 571 nm/RIU with a good linearity (not shown), and a FOM of 68 RIU-1. We have also demonstrated real-time monitoring of the immobilization of Human Immunoglobulin G (hIgG) molecules onto the fiber sensor, and the association and dissociation processes between hIgG and its binding partner anti-hIgG, as in Fig. 1(c). The refractive index DL is 3.5h10-6 RIU at 1 s integration time (not shown), which is over an order of magnitude better than reported modified-end multimode fiber SPR devices, while there are no reports on previous SMF end-facet devices’ DL which have very low FOM values. In conclusion, we have demonstrated an efficiently fabricated plasmonic crystal cavity device on a SMF end-facet. It shows high performance for refractive index detection and can be readily applied to common fiber-based label-free biosensing experiments [7-9].
Fig. 1. (a) An optical micrograph and an SEM image of a plasmonic crystal cavity on the end facet of a 125 m diameter bare SMF. (b) Normalized reflection spectra when a sensor is immersed in different liquids. (c) SPR wavelength shift versus time elapse during biomolecule interactions. A slow baseline drift has been corrected.
[1] G. Kostovski, P. R. Stoddart and A. Mitchell, Adv. Mater. 26, 3798 (2014). [2] G. F. S. Andrade and A. G. Brolo, Nanoplasmonic Structures in Optical Fibers, A. Dmitriev, eds. (Springer, 2012). [3] Y. Lin, Y. Zou and R. G. Lindquist, Biomed. Opt. Express 2, 478-484 (2011). [4] H. Nguyen, F. Sidiroglou, S. F. Collins, T. J. Davis, A. Roberts and G. W. Baxter, Appl. Phys. Lett. 103, 193116 (2013). [5] X. He, H. Yi, J. Long, X. Zhou, J. Yang and T. Yang, arXiv:1512.02022 [physics.optics] (2015). [6] X. He, J. Long, H. Yi and T. Yang, in Frontiers in Optics Technical Digest (Optical Society of America, 2013), FTu1B. 1. [7] A. M. Shrivastav, S. K. Mishra and B. D. Gupta, Sensor Actuat. B: Chem. 212, 404-410 (2015). [8] D. Li, J. Wu, P. Wu, Y. Lin, Y. Sun, R. Zhu, J. Yang and K. Xu, Sensor Actuat. B: Chem. 213, 295-304 (2015). [9] S. Shi, L. Wang, R. Su, B. Liu, R. Huang, W. Qi and Z. He, Biosens. Bioelectron. 74, 454-460 (2015).
283 P-10-01
Local Refrigeration by Evanescent Anti-Stokes Luminescence
Ryotaro Togawa and Kotaro Kajikawa Interdisciplinary Graduate School of Science and Engineering, Tokyo Institute of Technology, Yokohama 226-8502, Japan E-mail address: [email protected]
Abstract: Local refrigeration by evanescent AS luminescence is reported. The observed decrease in temperature was approximately 3.4ºC using a 4.4 mW HeNe laser at 633 nm. This refrigeration method is useful for thermal study in nanometer region.
1. Introduction Ant-Stokes (AS) luminescence is the phenomenon that luminescence is observed at wavelengths shorter than the excited. The energy conversation is hold by thermal vibration and/or rotation energies, resulting in refrigeration. The optical refrigeration is based on AS luminescence has been mainly observed in a solid [1]. One group has reported on the optical refrigeration in liquid [2]. Their report is relatively large scale and no local refrigeration has been reported. Here we report local refrigeration by evanescent anti-Stokes luminescence. 2. Experiments The optical setup for local refrigeration is depicted in Fig. 1(a). A HeNe laser at O=633 nm (4.4 mW) was used for both refrigeration and temperature measurements. Since AS luminescence is sensitive for temperature, the temperature of the medium can be probed. The laser is focused at the bottom of the high index prism (SF-11, n=1.78) at total reflection geometry at 67.9º, which is larger than the critical angle of 53.6º. The evanescent AS luminescence is probed at the observation angle (55.0º) also larger than the critical angle. The AS luminescence spectra are recorded with a cooled-CCD-equipped spectrometer. The dye for AS luminescence is Rhodamine 101 in ethanol at a concentration of 1mM. 3. Results and Discussion Figure 1(b) shows the AS luminescence intensity as a function of illumination time. After 3h, the cooling and thermal dispersion seem to be in the equilibrium state and temperature stays constant. The corresponding decrease in temperature is approximately 3.4ºC. When we stop illumination, the temperature start to rise. The refrigeration occurs in the spatial region of near field, so it is limited to approximately 100 nm from the prism surface. Therefore this refrigeration method is useful for thermal study in nanometer region. 4. Conclusion Local refrigeration by evanescent AS luminescence is reported. This refrigeration method is useful for thermal study in nanometer region.
Fig. 1 (a) Optical Setup (b) AS luminescence as a function of illumination time.
[1] R. I. Epstein, M. I. Buchwald, B. C. Edwards, T. R. Gosnell and C. E. Mungan, Nature 377, 500-503 (1995). [2] J. L. Clark and G. Rumbles, Phys. Rev. Lett. 76, 2037-2039 (1996).
284 P-10-02
A photoconductor intrinsically has no gain
Yaping Dan1*, Xingyan Zhao1, Abdelmadjid Mesli2 1University of Michigan – Shanghai Jiao Tong University Joint Institute, Shanghai Jiao Tong University, Shanghai, China 2Institut Matériaux Microélectronique Nanosciences de Provence, UMR 6242 CNRS, Université Aix-Marseille, 13397 Marseille Cedex 20, France *Correspondence should be addressed to: [email protected]
Abstract: Semiconducting photoconductors have been widely reported to have an extraordinarily high gain (up to 108). In the past 50 years, the high gain is often explained by a widely accepted theory that the gain is equal to ܩൌ߬Ȁ߬௧ where ߬ is the minority recombination lifetime and ߬௧ the carrier transit time. The theory is derived on the assumption that the photogenerated excess carriers (ο݊ ൌ ݃ ή ߬ሻ are spatially uniform and independent of external voltage bias. In this Letter, we find that this assumption is not valid for a photoconductive semiconductor in contact with two metal electrodes. By solving the continuity equation and performing numerical simulations using commercial device simulators, we conclude that a photoconductor intrinsically has no gain, meaning that the gain will be no more than 1 no matter how short the transit time is. The high gain observed in experiments must come from other extrinsic effects on which we have offered a brief perspective.
285 P-10-03
A SNOM investigation of InGaN/GaN micropillars
Wai Yuen Fu, Jian-An Huang, Hoi Wai Choi* Department of Electrical and Electronic Engineering, the University of Hong Kong *E-mail address: [email protected]
Abstract: We present experimental observations of InGaN/GaN micropillars using a SNOM PL setup. A comparison of the spatial variations of the PL spectra has been made between two different Indium compositions of micropillars. The difference implies that the strain relaxation mechanism would change with the indium composition of the InGaN layers.
1. Introduction Micro-/nano- sized InGaN/GaN light-emitting diode (LED) has higher internal quantum efficiency (IQE) and light extraction efficiency than its bulk planar counterpart. Typically, a blue-shift of photoluminescence (PL) is also observed when the dimension is reduced. Previous theoretical studies claim that the phenomenon can be attributed to strain, polarization and quantum-confined Stark effect (QCSE) [1,2], despite a lack of experimental evidence in microscopic scale. Only Zhuang et al. [3] reported SEM-CL measurements on a low Indium composition single quantum well (QW) nanorod, showing a red-shift at the edge. Here we present an experimental investigation of the optical emissions from InGaN/GaN micropillars using scanning near-field optical microscopy (SNOM) PL. A SNOM tip can excite and collect PL locally so that the interaction volume is smaller. The observations of the spatial variations of PL on micropillars with different Indium composition would give more insight into the underlying mechanisms of the optical transitions. 2. Experiment InGaN/GaN LED samples with different Indium compositions are first patterned by nanosphere lithography with 2 μm silica microspheres, followed by inductively coupled plasma (ICP) etch for 120 s. The resultant micropillars are then observed using a SNOM PL setup (based on a NT-MDT NTEGRA NSOM microscope) under illumination collection mode with a 405 nm continuous-wave diode laser source. (a) (b)
2 μm
2 μm
Fig. 1: SNOM measurements of 2 μm InGaN/GaN micropillars with (a) blue and (b) yellow PL emissions, showing the amplitude (red) and wavelength (blue) of the PL peaks versus the distance from the center of the micropillars. Insets are the plan-view SNOM PL images. Note that there is still PL intensity outside the micropillar due to the finite size of the aperture and a small slope of the micropillars.
SNOM results in Fig. 1 show that even though the overall PL emissions from both the blue and green samples exhibit a blue-shift as reported by Bai et al. [4], the edge of the blue sample has a higher wavelength than that at the center (Fig. 1(a)), implying that the blue-shift is actually originating from a blue-shift at the center. The theories of Wu et al. [1] and Böcklin et al. [2] seem only to apply to samples with high indium composition, when the InGaN layer is highly strained. The blue-shift at the edge due to strain relaxation of the InGaN layers can only be observed when the probe is slightly outside of the micropillar, i.e., on the sidewall, such that the effect of the blue-shift can be isolated from the main PL emission, as shown in Fig. 1(b). 3. Summary We have investigated the PL characteristics of InGaN/GaN micropillars with different Indium compositions using a SNOM PL setup. The results show that the PL emission of the micropillars goes from blue-shift at the center to blue-shift at the edge when the indium composition increases. We will present our proposed strain relaxation mechanisms responsible for the change in PL spatial variations at the conference. 4. References [1] Y. R. Wu, C. Chiu, C. Y. Chang, P. Yu, and H. C. Kuo, IEEE JSTQE 15, 1226 (2009). [2] C. Böcklin, R. G. Veprek, S. Steiger, and B. Witzigmann, Phys. Rev. B 81, 155306 (2010). [3] Y. D. Zhuang, J. Bruckbauer, P. A. Shields, P. R. Edwards, R. W. Martin, and D. W. E. Allsopp, J. Appl. Phys. 116 , 174305 (2014). [4] J. Bai, Q. Wang, and T. Wang, J. Appl. Phys. 111, 113103 (2012).
286 P-10-04
Amorphous silicon based p-i-n photodiode structure for enhanced optically induced dielectrophoresis (ODEP) performance of micro-beads and cell manipulation
Anirban Das1, Song-Bin Huang3, Min-Hsien Wu3, Yen-Heng Lin2,4, Chao-Sung Lai 2,3* 1Department of Electrical Engineering, Indian Institute of Technology, Madras, Tamil Nadu, India 2Chang Gung University, Department of Electronic Engineering, 259 Wen-Hwa 1st Road, Taoyuan, Taiwan, 333 3Chang Gung University, Institute of Biochemical and Biomedical Engineering, 259 Wen-Hwa 1st Road, Taoyuan, Taiwan, 333 4Chang Gung University, Institute of Medical Mechatronics, 259 Wen-Hwa 1st Road, Taoyuan, Taiwan, 333 E-mail address: [email protected]
Abstract: Modulation of the impedance of the light-addressable photoconductive layer in ODEP chip is one of the key issues for its manipulating performance. In this study, the amorphous silicon (a-Si) based p-i-n photodiode structure as a photoconductive light-addressing layer in the ODEP chip is introduced to enhance its manipulation efficiency. A comparative study of the manipulation performance for micro-particle and OEC-M1 cell was evaluated quantitatively between the p-i-n photodiode and the conventional a-Si based ODEP chip. It was observed that under the same operating condition, p-i-n photodiode based ODEP chip gains about 2-fold higher manipulation efficiency over the conventional one. The development of this promising platform may provide a higher efficient ODEP.
1. Introduction In ODEP scheme, optical patterns on the photoconductive surface are utilized as virtual electrode to address flexible and reconfigurable DEP traps. It has wide range of application in cell, micro-particle and nanowire manipulation [1-3]. The ratio of photo to dark conductivity of the photoconductive layer plays a key role in ODEP activation. In this study, a- Si: besed p-i-n photodiode structure is proposed as a light-activated layer. 2. Results and discussion The schematic illustration of the experimental setup is shown Fig. 1. To make a comparative study, three different bottom electrodes as a photoconductive layer in the ODEP chip were designed and their corresponding cross-sectional schematics are shown in Fig. 2. To figure out the manipulation performance of different structures, both micro-beads and OEC-M1 cell were experimentally manipulated under different operating conditions and the condition details are summarized in table 1. Fig. 3 represents the terminal velocities for beads manipulation and were measured to be 541.3 r 50.6 Pm s-1, 360.6 r 36.8 Pm s-1 and 269r17.6 Pm s-1 for type III, II and I structure respectively. Fig. 4 shows results for OEC-M1 cell manipulation, the terminal velocities for type III, II and I structure were measured to be 420.5 r 76.1 Pms-1, 302 r 44.3 Pm s-1 and 189 r 49.2 Pm s-1 respectively. About 2-fold (541/269 = 2.01 for beads and 420/189 = 2.22 for OEC-M1 cell) enhancement of the manipulation efficiency was observed in type III structure relative to type I structure.
3. Conclusion This work revealed the enhancement of the manipulation performance of ODEP chip by replacing conventional a-Si layer with a p-i-n photodiode layer. It has great potential to manipulate cell in physiological buffer solution. 4. References [1] PY Chiou, AT Ohta and MC Wu. Nature. 436, 370-372 (2005). [2] JA Rogers. Nat Photonics. 2, 69-70 (2008). [3] AT Ohta, M Garcia, JK Valley, L Banie, HY Hsu, A Jamshidi, SL Neale, T Lue, MC Wu. Lab Chip 10, 3213-3217 (2010).
287 P-10-05
Thermally Stable Paper Photodetectors Based on BN Nanosheets
Chun-Ho Lin, Meng-Lin Tsai, Hui-Chun Fu and Jr-Hau He King Abdullah University of Science and Technology, Thuwal 23955-6900, Saudi Arabia E-mail address: [email protected]
Abstract: Paper-based electronics shows great potential to meet the increasing demand of internet of things due to its popularity, flexibility, low cost, mass productivity, disposability, and ease of processing. However, conventional flexible devices made of paper and plastic substrates are expected to have thermal issues due to their poor thermal conductivity. In this work, we demonstrated flexible solar-blind deep-ultraviolet sensors based on 2D boron nitride nanosheets composited paper with fast recovery time (down to 0.393 s), great thermal stability (146 W/m K, 3-order-of-magnitude larger than conventional flexible substrates), excellent flexibility and bending durability (showing repeatable ON/OFF switching during 200-time bending cycles). This shows great potential to be a key component to solve thermal problems and fully activate flexible electronics for meeting the demand of internet of things.
1. Structure of BN paper 3. Thermal stability and Flexibility Table 1. (a) Comparison of the thermal conductivity between typical flexible substrates and BN paper in this work.
Figure 1. (a) Photograph of BN paper. (b) Schematic to show the structure of cellulose nanofiber with layered boron nitride nanosheets. (c) SEM surface morphology image of nanocomposite BN paper. (d) TEM image and (e) diffraction pattern of BN nanosheets to illustrate its crystalline property. (f) High-resolution TEM image showing the edge of BN nanosheets. Figure 3. (a) Dark current and photocurrent as a 2. Characteristics of BN paper photodetector function of temperature under 10 V bias and 185- nm light illumination with the light density of 15.28 mW/cm2. (b) Temperature dependent responsivity of BN paper PD under a bias of 10 V.
Figure 2. (a) I–V curves of BN paper PD Figure 4. (a) Optical images and (b) corresponding measured in the dark and under 185-nm DUV ON/OFF distribution of photosensors as a illumination (b) The time-resolved photoresponse function of bending radius of curvature (R). (c) of the device at 10 V bias. (c) Photoswitching ON/OFF distribution as a function of bending speed of the photodetector at 10 V bias. (d) time with a bending radius of 1 cm Schematic of the BNNS–BNNS junction barrier for the carrier transport in the BN paper PD.
288 P-11-01
A Novel Method for Fabrication of the Semiconductor Nanomaterials
Meng Xiangdong 1,2 , Yu Zhaoliang1,2 , Hu Yue1, Qu Xiaohui 1, Sun Meng1, Zhao Jialong1, Li Haibo1,2 1. Key Laboratory of Functional Materials Physics and Chemistry of the Ministry of Education, Jilin Normal University, Changchun 130023, Chinaǹ2. State Key Laboratory of Inorganic Synthesis and Preparative Chemistry, Jilin University, Changchun 130023, China E-mail address: ([email protected])
Abstract: We use a novel method to fabricate special nanostructures semiconductor (Ge, Si, SiGe and Ga) with laser irradiation on the ionic liquid 1-ethyl-3-methylimidazolium bis(trifluor-omethylsulfonyl) amide ([EMIm]Tf2N) containing different electrolyte at room temperature. The effect of laser during electrodeposition has been investigated by Cyclic voltammetry, SEM, HTEM, X-ray diffraction, Raman spectra and X-ray photoelectron spectroscopy. Laser has an impact on the electrodeposition process of all four materials, make the reaction more easily and deposition rate becomes faster. Laser has also affected the microscopic morphology and crystalline state of the semiconductor materials. We explain the special nanostructure growth mechanism under laser irradiation. The significant effect of laser on the ionic liquids electrodeposition process might open up new avenues for the naofabrication of nanostructures semiconductor materials.
ġġ Fig.1 Ge nanostructures obtained after applying a constant potential of −1.68 V for 1200s in the presence of 532 nm laser.
References: [1] A. Ispas, A., Bund, A. Electrodeposition in Ionic Liquids. Electrochemical Society Interface, 47-51 (2014). [2] E. G. Gebresilassie , M. Armand, B. Scrosati, S. Passerini, Energy storage materials synthesized from ionic liquids. Angewandte Chemie, 53(49):13342–13359 (2014). [3] A. Lahiri, A. Willert, S. ZE. Abedin, A simple and fast technique to grow free-standing germanium nanotubes and core-shell structures from room temperature ionic liquids. Electrochimica Acta, 121(3):154–158 (2014). [4] N. Qiong, L. C. Richard, C. Gary. J, Laser assisted electro-deposition of earth abundant Cu2ZnSnS4 photovoltaic thin film. Manufacturing Letters, 1(1):54–58 (2013)
289 P-11-03
Template-Stripped Pyramid Nanostructures as Plasmonic Perfect Absorber fabricated using Nanosphere Lithography
Chen-Chung Yen1, Chi-Ching Liu2, Yang-Fang Chen1,2, and Yun-Chorng Chang*1,2 1. Department of Physics, National Taiwan University, Taipei, Taiwan 2. Research Center for Applied Sciences, Academia Sinica, Taipei, Taiwan E-mail address: [email protected]
Abstract: In this study, we demonstrate an economic fabrication method to fabricate pyramid nanostructure on flexible substrates. First, Nanosphere Lithography is used to define the periodic circular nanohole arrays made from silicon oxide. The diameter of the hole ranges from 300 to 500 nm. The periodicity can be tuned by varying the diameter of the nanospheres. Silicon hard mold with inverted pyramid holes can be fabricated following silicon anisotropic wet etch. After depositing Au film on the of the silicon mold, precursor of PDMS is spread on the sample surface and cured at high temperature. Arrays of Au pyramid can be obtained following regular template-stripping method. The optical reflection and absorption spectroscopy of the fabricated nanostructures are investigated. The results indicate that these nanostructures might leads to possible applications for tunable perfect absorbers.
290 P-11-04
Mathematical analysis of femtosecond laser nanoscale ablation for PMMA and ABS/PVC
B. C. Chen a, C. Y. Ho b,*, M. Y. Wenc , J. W. Yu b, and Y. H. Tsai b aDepartment of Chinese medicine, Buddhist Dalin Tzu Chi General Hospital, Chiayi 622, Taiwan bDepartment of Mechanical Engineering, Hwa-Hsia University of Technology, New Taipei City 235, Taiwan cDepartment of Mechanical Engineering, Cheng Shiu University, Kaohsiung 833, Taiwan
Abstract: This paper analytically investigates the femtosecond laser nanoscale ablation of PMMA and ABS/PVC. Pulsed laser ablation is a well-established tool for polymer. However the ablation mechanism of laser processing for polymer has not been thoroughly understood yet. This study utilized a thermal transport model to analyze the relationship between the ablation rate and laser fluence. This model considered the energy balance at the decomposition interface. The calculated variation of the ablation rate with the logarithm of the laser fluence agrees with the measured data. It is also validated in this work that the variation of the ablation rate with the logarithm of the laser fluence obeys Beer’s law.
Keywords: PMMA; Ablation; Femtosecond laser; ABS/PVC.
*Author to whom all correspondence should be addressed. Email: [email protected] (C. Y. Ho).
291 P-11-05
Formation of uniform high-density and small-size Ge/Si quantum dots by pulsed laser annealing of pre-deposited Ge/Si film
Hamza Qayyum1,2,3, Chie-Hsun Lu1,2, Ying-Hung Chuang1,4, Jiunn-Yuan Lin4, Szu-yuan Chen1,2,3,* 1Institute of Atomic and Molecular Sciences, Academia Sinica, Taipei 106, Taiwan 2Department of Physics, National Central University, Chungli 320, Taiwan 3Molecular Science and Technology Program, Taiwan International Graduate Program, Academia Sinica, Taipei 115, Taiwan 4Department of Physics, National Chung Cheng University, Chia-Yi 621, Taiwan E-mail address: ( *[email protected])
Abstract: The capability to fabricate Ge/Si quantum dots with small dot size and high dot density uniformly over a large area is crucial for many applications. In this work, we demonstrate that this can be achieved by moving a line-focused pulsed laser beam across pre-deposited Ge thin film on Si substrate to induce formation of quantum dots. With suitable setting Ge/Si quantum dots with a diameter of |25 nm and a dot density of 6u1010 cm-2 could be formed over an area larger than 12 mm2. The technique could be applicable to other materials besides Ge/Si.
Due to the confinement of carriers in three dimensions, semiconductor quantum dots (QDs) are endowed with many interesting physical properties that have made QDs a promising candidate for developing novel electronic and optoelectronic devices [1]. However, the optoelectronic applications of QDs are hindered by the necessity to achieve the small dot size and high dot density required. The Stranski–Krastanow (S–K) growth mode is the most commonly adopted method for fabricating quantum dots [2], in which QDs form by a spontaneous self-assembly process and thus the dot characteristics could not be controlled. Although it has been reported that the size of Ge QDs could be reduced and the dot density could be raised by pre-depositing submonolayer carbon [3] or ultrathin SiO2 layer on the Si substrate before depositing Ge [4], such methods inevitably introduce interfacial species which may modify the electronic structure of Ge QDs. Here we report the fabrication of Ge/Si quantum dots with a diameter of 25 ± 6 nm and a dot density of 6u1010 cm-2 by pulsed laser annealing of pre-deposited flat Ge film on Si (100) substrate. The average size of the QDs is smaller while the dot density is larger than that of the QDs formed by the Stranski–Krastanov growth mode occurring spontaneously during deposition. In addition, the region of uniform dot size and density distribution can be larger than 12 mm2. This is accomplished by using a scanned, line-focused, 532- nm laser beam to induce formation of QDs. Based on the dependence of the QD size and density on the peak fluence of the laser pulse, the scan speed of the laser beam, and the thickness of the pre-deposited Ge film, a model based on laser-induced strain, surface diffusion, and Oswald ripening is proposed for the mechanism underlying the formation of the Ge QDs.
Fig.1. AFM images (1 μm x1 μm) of Ge thin film on Si substrate before and after pulsed laser annealing.
References [1] K. L. Wang, D. Cha, J. Liu, and C. Chen, Proceedings of the IEEE 95, 1855-1883 (2007). [2] D. J. Eaglesham and M. Cerullo, Phys. Rev. Lett. 64, 1943-1946 (2000). [3] A. Beyer, E. Müller, H. Sigg, S. Stutz, D. Grützmacher, O. Leifeld, and K. Ensslin, Appl. Phys. Lett. 77, 3218-3220 (2000). [4] A .A. Shklyaev, M. Shibata, and M. Ichikawa, Phys. Rev. B 62, 1540-1545 (2000).
292 P-11-06
Sub-wavelength Patterning of 2D and 3D Nanostructures using Femto-second Laser Lithography without Two- photon Dye
Raghvendra P Chaudhary, Arun Jaiswal, Suyog R Hawal, Sumit Saxena and Shobha Shukla* Nanostructures Engineering and Modeling Laboratory, Department of Metallurgical Engineering and Materials Science, Indian Institute of Technology Bombay, Mumbai, MH, India 400076 *[email protected]
Abstract: Two-photon absorption enables direct 2D & 3D lithography of micro/nano structures inside both negative-tone and positive-tone oligomers with high spatial resolution. Nonlinear interactions of short pulse laser with materials enables the absorption to be confined in a small volume of the order of λ3 (λ= laser wavelength) at the focus and hence the polymerization volume gets reduced below the diffraction limit. This nonlinear interaction is facilitated using 2-photon absorbing dyes, which transfer the energy to curing agent or photo initiator present in photo-polymer matrix. Unfortunately most of these 2- photon dyes are extremely expensive thereby limiting the scope of this useful technique. Here we present a simple, one-step technique for direct-writing of 2D & 3D micro/nano structures, with sub-wavelength line widths, utilizing two-photon absorbing property of photocuring agent mixed in oligomer without using any two-photon absorbing dye. Complex 2D and 3D patterns were fabricated with sub-micron resolution, in commercially available liquid resin. The technique presented here offers a cost-effective approach for the fabrication of high resolution 2D and 3D engineered devices and find vast applications in optoelectronic devices.
Keywords: Nanofabrication, Nonlinearity, Sub-wavelength lithography.
293 P-11-07
Growth behavior of InN in pits with different size on GaN substrate
Chien-Ting Kuo,1,4 Lung-Hsing Hsu,1,4 Yung-Yu Lai,2 Hao-Chung Kuo,3 Chien-Chung Lin,4 and Yuh-Jen Cheng5,* 1Institute of of Lighting and Energy Photonics, College of Photonics, National Chiao-Tung University, No.301, Gaofa 3rd. Road, Guiren Township, Tainan County 71150, Taiwan. 2Department of material science and engineering, National Chiao Tung University, 1001 Ta Hsueh Rd, Hsinchu, Taiwan. 3Department of Photonics and Institute of Electro-Optical Engineering, National Chiao Tung University, 1001 Ta Hsueh Rd, Hsinchu 30010, Taiwan. 4Institute of Photonic System, College of Photonics, National Chiao-Tung University, No.301, Gaofa 3rd. Road, Guiren Township, Tainan County 71150, Taiwan. 5Research Center for Applied Sciences, Academia Sinica, 128 Sec. 2, Academia Rd, Nankang, Taipei 115, Taiwan. *[email protected]
Abstract: InN is important in the III-nitride semiconductor family for light emitting device applications. It is still challenging to grow InN due to the low dissociation temperature and lack of suitable substrates. We report the crystal growth behavior of InN in pits with different size on a GaN substrate. Hexagonal inverted pyramidal pits were fabricated by selective area growth on a GaN substrate. Crystalline InN can grow from the bottom of V- pits with ~1 Pm size while grows from the edges of hexagonal pits when the pit size is larger than 2 Pm. The growths of InN at specific locations were attributed to the changing surface angles at the junctions of crystal planes. The junction corners provided nucleation sites to start the InN crystal growth.
III-nitride semiconductor is an important material for light emitting devices in the visible spectral range. The bandgap of this semiconductor compound can potentially cover from 6.2 eV (AlN), to 3.4 eV (GaN), and all the way down to 0.7 eV (InN). The material growth and device development have made great progress for GaN and GaN with small Al or In incorporation. Extending the development to longer wavelength with high In contect have attracted high interests. Development of InN growth plays a key role for extending the wavelength range to red and infrared range. InN is hard to grow due to its low dissociation temperature and lack of suitable substrates. Here, we report the study of InN growth from pits with different size on a GaN substrate. We first fabricated pits on a GaN substrate by selective area growth. SiOx disks of 5 Pm diameter were first fabricated on a sapphire substrate by standard micro fabrication process. GaN was grown from the sapphire surface and laterally over the SiOx disk surface. Inclined crystal facets were formed during the lateral growth over SiOx. These crystal facets created inverted pyramidal pits as they coalesced. A growth temperature gradient on the substrate was created during growth to generate V-Pits with different size, as shown in Fig. 1. InN was then grown by MOCVD on the surbstrate. The growth started from the bottom of the V-pits with ~1Pm size (Fig. (a-1) and (b-1)), while the growth started from the edges of V-pits with size larger than 2 Pm (Fig. (c-1)-(g-1)). The change of surface angle at the junction of different crystal facets created nucleation sites to promote InN crystal growth. The precise nucleation control from the V-pits with ~1Pm size is useful to grow crystalline InN at designed locations.
Fig. 1 (a)-(g). Pits with different size Fig. 2 (a1)-(g1). Pits with different size fabricated by selective area growth. The fabricated by selective area growth with a lateral over growth on SiOx disk to form temperature gradient applied from (a1) to pits are shown in the lower right. (g1) location.
[1] L.-H. Hsu, C.-T. Kuo, J.-K. Huang, S.-C. Hsu, H.-Y. Lee, H.-C. Kuo, C.-C. Lin et al., "InN-based heterojunction photodetector with extended infrared response," Optics Express, vol. 23, pp. 31150-31162, 2015.
294 P-12-01
Two photon absorption and fluorescence of gold nanoclusters
Joanna Olesiak-Banska, Magdalena Waszkielewicz, Marek Samoc Advanced Materials Engineering and Modelling Group, Faculty of Chemistry, Wroclaw University of Technology, Wroclaw 50-370, Poland E-mail address: [email protected]
Abstract: Optical properties of gold nanoclusters differ significantly from those for the plasmonic gold nanoparticles, in both linear and nonlinear regime. Although the linear optical properties have been systematically studied both experimentally and theoretically, nonlinear optical properties (NLO) were usually investigated at a single wavelength and the results provided fragmentary information only. Moreover, large differences in the values of two-photon absorption (TPA) cross-sections have been reported in the literature, from several hundred GM to several hundred thousand GM. Here, we present a study of third- order nonlinear optical properties of captopril-protected gold clusters in a wide range of wavelengths. We apply the z-scan technique to obtain a full TPA spectrum of the nanoclusters in water, this information being particularly important for application of the nanoclusters in multiphoton imaging. We discuss the results with reference to TPA of plasmonic gold nanoparticles and literature data on NLO properties of gold nanoclusters.
Nanoclusters are a new class of metallic nanomaterials, which consist of the central metal atoms surrounded by different types of ligands. Because of their size (1-2 nm), nanoclusters give distinct quantum- size effect, which leads to a discrete electronic structure in the core. The spectra exhibit molecular-like one- electron transitions rather than collective excitation like in metallic gold nanocrystals. The unique electronic and geometric structure of nanoclusters gives rise to interesting combination of properties like chirality, magnetism, redox chemistry, etc [1, 2]. Thus, nanoclusters have gained great interest and applications in catalysis, photonics, biosensing and molecular electronics [1, 2].
Fig. 1. Transmission electron microscopy image of gold nanoclusters (scalebar 5 nm).
In this contribution we report on the investigation of nonlinear optical properties of thiolate-protected gold nanoclusters (Au25Capt18). The nanoclusters were synthesized from Au(I)Capt polymers by reductive decomposition [3, 4]. We identified the nanoparticles morphology and dimensions with transmission electron microscopy (TEM) as well as performed a full characterisation of their optical properties (absorption, fluorescence, CD spectra). Both structural and optical properties confirmed the fabrication of monodisperse nanoclusters with the core composed of 25 Au atoms (Fig.1.). Then, we investigated the third-order nonlinear optical properties of the clusters with the z-scan technique, in a broad range of wavelengths. This allowed us to observe a wavelength-dependent interplay between two-photon absorption and saturable absorption phenomena. We discuss the results in detail and compare them to third-order nonlinear optical properties of plasmonic gold nanoparticles [5]. Finally, we imaged the nanoclusters under a multiphoton microscope and performed the analysis of two-photon excited luminescence to determine the feasibilty of applying these nanomaterials as optical markers for microscopy. References [1] R. Jin, Nanoscale 2, 343-362 (2010). [2] Y. Lu and W. Chen, Chem. Soc. Rev. 41, 3594- 3623 (2012). [3] S. Kumar and R. Jin, Nanoscale 4, 4222-4227 (2012). [4] J. Olesiak-Banska, M. Waszkielewicz, M. Wojtas, M. Rozycka, A. Bansal, K. Matczyszyn, A. Ozyhar, I. Samuel and M. Samoc, submitted [5] J. Olesiak-Banska, M. Gordel, R. Kolkowski, K. Matczyszyn and M. Samoc J. Phys. Chem. C 116, 13731−13737 (2012).
295 P-12-02
pH-dependent luminescence enhancement and size- transformations of gold nanoclusters
M. Waszkielewicz1, J. Olesiak-Banska1, A. Bansal2, K. Matczyszyn1, I.D.W. Samuel2, M. Samoc1 1Advanced Materials Engineering and Modelling Group, Wroclaw University of Technology, Wybrzeze Wyspianskiego 27, 50-370 Wroclaw, Poland 2Organic Semiconductor Centre, SUPA, School of Physics & Astronomy, University of St Andrews, North Haugh, St Andrews KY16 9SS, Scotland, UK E-mail address: [email protected]
Abstract: Thiolate gold nanoclusters have recently attracted considerable attention due to their new physicochemical properties such as chirality, size-dependent luminescence and magnetism. With advantages of long lifetime, large Stokes shift, excellent photostability and biocompatibility, they seem to be an interesting material for bioimaging. On the other hand, the application is limited by low luminescent quantum yield and inhomogeneity of sample after synthesis. Hereby, we report the luminescence enhancement by nanoclusters treatment with low pH and chloride ions. We characterized the new-created particles with spectroscopic techniques like absorption and circular dichroism. The size transition was observed and preparation of only one enantiomer was confirmed, which is particularly important for applications in biology. The impact of ion’s type was also examined.
Nanoclusters are noble metal structures with diameter below 2 nm, which possess discrete energy levels and do not display a typical surface plasmon resonance (SPR), which is characteristic for nanocrystals [1, 2]. The luminescence of this molecular-like structures is often attributed to particle size effect, but it also depends on other structural parameters such as the type of surface ligands [3]. The particular influence of these structural factors on emission properties and mechanisms is still discussed. Due to their high efficiency in one- and two-photon excited fluorescence, high two – photon absorption cross sections, low toxicity, excellent chemical and photostability for long periods of time nanoclusters offer great opportunities for multiphoton fluorescence bio-imaging. This contribution is focused on the pH-dependent changes of structure and optical properties of gold- captopril nanoclusters (Au25Capt18). The well-defined nanoclusters were obtained in the one-pot synthesis by reductive decomposition of Au(I)Capt polymers with sodium borohydride [4]. We investigated the optical properties of nanoparticles in wide range of pH (from 2 to 10) and we observed the crucial spectra changes in pH 2. To trace the origin of the changes and explain the ion impact on the optical properties, we followed additional measurements of samples with different acids and we described chloride ion significance. - We also determined the transformation development of Au25Capt18 to Au28Capt20 in time in presence of Cl . Finally, the luminescence lifetimes of the samples were recorded. pH2 200 pH3 pH7 180
160 1,0 pH2 pH3 140 pH7 120
100
0,5 80 Absorption
norm PL intensity norm PL intensity 60
40
20
0,0 0 400 500 600 700 800 900 1000 600 650 700 750 800 wavelength [nm] wavelength [nm]
Fig. 1. Absorption and emission spectra of AuCapt in a range of pH.
[1] R. Philip, P. Chantharasupawong, H. Qian, R. Jin J. Thomas, Nano Lett., 12, 4661 (2012) [2] E. Oh, F. Fatemi, M. Currie, J. Delehanty, T. Pons, A. Fragola, S. Lévêque-Fort, R. Goswami, K. Susumu, A. Huston, I. Medintz, Part. Part. Syst. Charact., 30, 453 (2013) [3] J. Zheng, C. Zhou, M. Yu, J. Liu, Nanoscale, 4, 4073 (2012) [4] S. Kumar, R. Jin, Nanoscale 2012, 4, 4222
296 P-12-03
Enhanced Photoacoustic Signal Intensity of Gold Nano- colloidal Suspensions Irradiated by Femtosecond Laser
Frances Camille P. Masim,1 Hao-Li Liu,2 Wei-Hung Hsu,1 and Koji Hatanaka1,2* 1Research Center for Applied Sciences, Academia Sinica, 2Department of Electrical Engineering, Chang Gung University E-mail address: [email protected]
Abstract: Enhanced photoacoustic (PA) signal intensity from gold nano-sphere and nano-rod colloidal suspensions under the condition of tightly-focused femtosecond pulsed laser irradiation was systematically investigated. PA signal amplitudes were measured by ultrasound transducers at frequencies of 5, 10, and 25 MHz. The experimental results revealed a linear-dependence of the relative photoacoustic amplitude to laser power and the mechanism was attributed to non- radiative conversion of absorbed light energy into heat and its accompanying acoustic effects. Gold nano-rod with longitudinal absorption peak at 800 nm which coincides with the wavelength of femtosecond laser leads to higher PA signal intensity generation. No shape deformation and thermal stability of gold nanoparticles were demonstrated.
In recent studies, photoacoustic (PA) wave emission from gold nano-particles induced by nanosecond laser irradiation was reported and the mechanism was attributed to non-radiative relaxation dynamics of surface plasmon resonance [1-4]. However, thermal instability and shape deformation of gold nano-particles which result in decay of PA signal intensity were reported [1-3]. In this presentation, an enhanced PA signal intensity from gold nano-colloidal suspensions with different particle shapes under the condition of tightly- focused femtosecond-pulsed laser (800 nm, 1 kHz, 35 fs) irradiation was investigated. PA signal intensity from gold nano-colloidal suspensions in a glass tube was measured by ultrasound transducers at frequencies of 5, 10, and 25 MHz. Sample suspensions were with gold nano-spheres with diameter of 20 nm and gold nano-rods with dimensions of 35 x 12 nm. Fig. 1 (a) shows a representative PA signal in time domain; the first peak represents the fundamental ultrasound signal and the second peak corresponds to the internal reflection of ultrasound waves from the inner surface of the glass tube with diameter of 5 mm. The time interval between the two peaks is 4.22 μs which can be ascribed to the sound velocity in bulk gold (v = 3,240 m/s), not in water (v = 1,482 m/s). Fig. 1 (b) shows a linear-dependence of the relative PA amplitude to laser power at 5 MHz. The longitudinal absorption band of gold nano-rods at the wavelength of 800 nm, which coincides with the wavelength of the femtosecond laser, leads to higher PA signal generation. On the other hand, gold nano-spheres without effective absorption at the laser wavelength generate lower PA signal intensity. The similar tendency was also observed at 10 and 25 MHz, while PA intensity decreases as frequency increases. No significant shape deformation of gold nano-rods and nano-spheres was observed before and after the experiments under our experimental conditions. Hence, thermal stability and increase in acoustic wave emission from femtosecond laser-irradiated gold nano-particles was demonstrated.
Fig. 1 Representative PA signal in time domain (a) and PA amplitude dependence with laser power at 5 MHz (b), inset shows PA amplitudes at 5, 10 and 25 MHz under 100 mW laser power irradiation
[1] S. Link and M. A. El-Sayed, J. Phys. Chem. B. 103, 8410-8426 (1999). [2] H. Petrova, J. P. Juste, I. Pastoriza-Santos, G. Hartland, L. M. Liza-Marzan and P. Mulvaney, Phys. ġ Chem. 8, 814-821 (2006). [3] T. A. El-Brossy, T. Abdallah, M. B. Mohamed, S. Abdallah, K. Esawi and H. Talaat, Eur. Phys. J. Special Topics. 153, 361-364 (2008). [4] T. Fukusawa, H. Shinto, H. Aoki, S. Ito and M. Ohshima. Adv. Pow. Tech. 25, 733-738 (2014).
297 P-12-04
Intensified photocatalytic efficiency by plasmonic field confinement with nano Bowtie and Diabolo structure under LED
Chia-Hua Lee1, Shih-Chieh Liao1, Tzy-Rong Lin1, Shing-Hoa Wang1, Dong-Yan Lai2, Po-Kay Chiu3 Jyh-Wei Lee4, Wen-Fa Wu2 1Department of Mechanical Engineering, National Taiwan Ocean University, Keelung 20224, Taiwan 2 National Nano Device Laboratories, National Applied Research Laboratories, Hsinchu 300, Taiwan 3 Instrument Technology Research Center, National Applied Research Laboratories, Hsinchu 30076, Taiwan 4Department of Materials Engineering, Ming Chi University, Xinbei 24301, Taiwan E-mail address: [email protected], [email protected], [email protected]
Abstract: The motivation of this study is to use LSPR enhancing the visible light absorbance for promoting a high functional photocatalyst by making the nano silver bowties and diabolos with varied tip angles embedded on the anatase TiO2 film as a new device. The influence and the mechanism of different tip angles caused various surface plasmon resonance and the electric field enhancement was investigated for exploring the most effectual photocatalyst being applicable to visible light irradiation. The experimental and simulated results in both nano bowtie and nano diabolo structure show that not only the localized surface plasmon resonance (LSPR) enhances, but also the Raman intensity amplifies as the tip angle reduces.
1. Introduction A strong photocatalytic activity and chemical stability of non-toxic titanium dioxide (TiO2) has applied to the environmental treatments, such as the water and air purification, disinfection and sterilization by decomposing the toxic organic and inorganic contaminants [1-2]. The most widely accepted photocatalytic mechanism is the electrons transit from valence band to conduction band to form many electron-hole pairs. These hole-electron pairs react with adsorbed oxygen and water on the photocatalyst surface, and produce free radicals to decompose organics into water and carbon dioxide, resulting in degradation of the adsorbates [3]. For promoting the photocatalytic efficiency under visible light, the surface plasmon resonance be confined in the vicinity of this small metal defect, often called localized surface plasma resonance (LSPR) [4]. Thus the induced high intensity of local electric fields by LSPR can create many hole-electron pairs by the strong light absorbance in this new device of photocatalyst with nano silver bowtie and diabolo structures [5]. 2. Method Photoresist and electron beam lithography technique were used to fabricate the embedded nano silver bowtie and diabolo structure with the various tip angles on the surface of titanium dioxide film. In the meantime, the finite-element method (FEM) was utilized to confirm the experimental results and the shift trend of plasmon resonant peak wavelengths as the tip angle change. 3. Result and Discussion In the long wavelength region as tip angle reduces, the resonant peak wavelength of the standing wave matches the lengthened length of prism edges at the bowtie and diabolo to make a blueshift. On the other hand, in the short wavelength region as the tip angle reduces, the redshift of resonant peak wavelength presumably attributes to the increase in the effective index of the local surface plasmon polariton (SPP) standing wave mainly resided along the both bowtie axis and diabolo axis. The fastest photocatalytic rate by placing bowtie Ag/TiO2 with tip angle 30° in methylene blue solution reveals the best degradation efficiency resulting from the strongest light absorption intensity. Because a great amount of light absorbance can stimulate a lot of valid radicals by surface plasmon resonance intensified photocatalytic interaction under light-emitting diode (LED) irradiation. 4. Conclusion Surface plasmon resonance enhanced Raman peak intensity is very significant by bowtie Ag/TiO2 and diabolo Ag/TiO2 nano structure rather than bare TiO2 to verify this successful design and fabrication. The simulation results of redshift and blueshift trend in the resonant peak wavelength agree well with that of the experimental results. Two of the strongest light absorbance at around 400 nm and 750 nm within visible light region for nano bowtie Ag/TiO2 photocatalyst with a 30° tip angle is attributed to the reinforced localized surface plasmon resonance at the tip gap of nano bowtie and the corners of nano diabolo. 5. References [1] M.R. Hoffmann, S.T. Martin, W. Choi and D.W. Bahnemann, Chem. Rev., 1995, 95, 69–96. [2] A. Fujishima, T.N. Rao and D.A. Tryk, Photochem. Rev., 2000, 1, 1–21. [3] P.V. Kamat and D. Meisel, Curr. Opin. Colloid&Interface Sci., 2002, 7, 282–287. [4] J. Zhao, X. Zhang, C. R. Yonzon, A. J. Haes and R. P. V. Duyne, Nanomedicine, 2006, 1(2), 219-228. [5] Z. Zhang, A. W. Bargioni, S. W. Wu, S. Dhuey, S. Cabrini and P. J. Schuck, Nano Lett, 2009, 9, 12, 4505-4509
298 P-12-05
The Structural and Optical Properties of ZnO Thin Film Nanostructures Based on Different Crystallographic Orientation of the Al2O3 Substrate
Ching-Hsiang Chan1, Shang-Hsuan Wu1, Ching-Hang Chien1,2,3, Yia-Chung Chang1,4* 1Research Center for Applied Sciences, Academia Sinica, Taipei 115, Taiwan 2Nano Science and Technology Program, TIGP, Academia Sinica, Taipei 115, Taiwan 3Department of Engineering and System Science, National Tsing Hua University, Hsinchu 300, Taiwan 4Department of Physics, National Cheng Kung University, Tainan 701, Taiwan E-mail address: [email protected]
Abstract: We provide a comprehensive study of ZnO thin film nanostructures based on different crystallographic orientation of the Al2O3 substrate. Several optical characterization techniques were performed to characterize the optical properties, anisotropy and surface structures. By comparing theoretical calculations with experimental measurements, the anisotropic properties of near-band-edge transitions can be determined.
Nowadays thin films have been widely used in various applications. This is due to the unique optical and electric properties of thin film structures. However, imperfections such as small crackers, isolated islands, and layer unevenness are inevitable in practical fabrication process of thin films [1]. Although the size of the imperfections is in nano-scale level [2], yet they do degrade the performance of thin film structure. Hence, characterization of thin film with high spatial resolution becomes critical to ensuring the performance of designed thin film devices [3]. In this work, we propose several optical methods, such as spectroscopic ellipsometry (SE), photoluminescence (PL), Raman and absorption spectroscopy for thin film characterization due to their advantage of non-destructiveness. The structure of ZnO thin film nanostructure grown on (0001) C-plane, (10ഥ0) M-plane, and (1ഥ02) R-plane sapphire substrates by using pulsed laser deposition (PLD) were investigated using X-ray diffraction (XRD), scanning electron microscopy (SEM) and field emission transmission electron microscopy (FE-TEM) analysis techniques. We also perform near-field microscopic image ellipsometry experiment to observe the surface of the nanostructures in order to verify their morphology. The ZnO film grown on the C-plane sapphire substrate has the smallest full width at half maximum (FWHM) values for both the X-ray (0002) diffraction peak and the PL peak for near-band-edge emission whereas that grown on the R-plane sapphire substrate has the largest FWHM values. On the other hand, the ZnO film grown on the C-plane sapphire substrate has the roughest surface. The low-temperature PL spectra show a series ultraviolet excitonic emission and weak deep-level emission, which indicate low structural defects in the films. The Raman spectra obtained with UV resonant excitation at room temperature show multi-phonon LO modes up to third order. Anisotropic optical properties of ZnO thin film nanostructures have been studied by means of SE and polarized optical transmittance spectra. Fig. 1. (a, b and c) shows low-temperature Ψ, Δ spectrum measured at three different angles (61, 67 and 73) of incidence for the ZnO film nanostructures on various substrate. Comparison with theoretical analysis will also be presented.
30 30 30 angle 61 angle 61 angle 61 angle 67 angle 67 25 angle 67 25 25 angle 73 angle 73 angle 73 20 20 20
15 15 15
in degrees in 10 degrees in 10 degrees in 10 < < <
5 5 5
1800 1800 1800 angle 61 angle 61 angle 61 150 angle 67 150 angle 67 150 angle 67 angle 73 angle 73 angle 73 120 120 120
90 90 90 in degrees degrees in degrees in
' 60 ' 60 ' 60
30 30 30
0 0 0 300 400 500 600 700 800 300 400 500 600 700 800 300 400 500 600 700 800 Wavelength (nm) Wavelength (nm) Wavelength (nm) (a) (b) (c) Fig. 1. Experimental Ellipsometric spectra of (a)ZnO/c-Al2O3 (b) ZnO/m-Al2O3 (c) ZnO/r-Al2O3 at 77K.
[1] G. Lang and G. Inzelt, Electrochimica Acta 36, 847-854 (1991). [2] S. B. Wang, Y. Xiao, H. K. Jia, and L. A. Li, Proc. SPIE 7375, 73755L (2008). [3] A. Karbassi, D. Ruf, A. D. Bettermann, C. A. Paulson, D. W. Van Der Weide, H. Tanbakuchi, and R. Stancliff, Rev. Sci. Instrum. 79, 094706 (2008).
299 P-12-06
Optical Characterization of Nanostructured In2O3 Thin Films
Ching-Hsiang Chan1, Li-Chia Tien2, Ching-Hwa Ho3* 1Research Center for Applied Sciences, Academia Sinica, Taipei 115, Taiwan 2Department of Materials Science and Engineering, National Dong Hwa University, Hualien 974, Taiwan 3Graduate Institute of Applied Science and Technology, National Taiwan University of Science and Technology, Taipei 106, Taiwan *E-mail address: [email protected]
Abstract: A detailed characterization focusing on the surface morphology, stoichiometry, structural, orientations and vibration modes of the metal-oxide thin film nanostructures of cubic-phase In2O3 (c-In2O3) with one-dimensional morphology have been carried out by means of field emission scanning electron microscopy (FESEM), field emission transmission electron microscopy (FETEM), and micro-Raman scattering. Several optical characterization techniques, such as thermoreflectance (TR) and photoluminescence (PL) were performed to characterize the optical properties of these samples. The near-band-edge and above-band-edge transitions, such as excitonic transitions, direct band gap and direct band gap with Burstein- Moss shift (BMS) effect of degenerate semiconductor have been determined by TR. PL measurements revealed the near-band-edge emissions and defect emissions.
To investigate the band character of In2O3, various experimental studies on electronic structure of c-In2O3 had ever been reported. Some experimental results showed this high-conductivity nanomaterial is a degenerate semiconductor with its Femi level (EF) higher above conduction-band edge (EC) to form BMS. [1,2] The BMS effect on the surface of In2O3 nanorod needs to be considered but the value of BMS (i.e. EF-EC) is difficult to measure directly by only transmittance or absorption measurements. In this study, there are two kinds of c-In2O3 thin film nanostructures have been grown by vapor transport method driven with vapor-liquid-solid mechanism on Si(100) substrate. The FESEM image indicated that different growth temperature and catalytic condition lead to different size and crystal and morphology of nanostructured In2O3 thin film. One dominated by nanowire aggregation, and the other one have tiny nanowires dispersed on continuous In2O3 film. The analyses of TEM image revealed that the samples have similar crystallized nanostractures of c-In2O3. The tapered tips and tower edges are usually the easily forming structures for the c-In2O3 nanorods with an axial direction grown along <100>. We successfully observed the band-edge excitonic transitions for the TR spectra from the In2O3 nanostructures which have better crystallization conditions. A comprehensive study for whole below- and above- band-edge transitions in c-In2O3 thin-film nanowires has been explored. For sample A, the energy of band-edge exciton E1 is 3.298 eV at room temperature. Excitonic binding energies of 40 meV for E1 and 10 meV for E2 for an exciton series can be observed by temperature-dependent TR measurements of sample A. The threshold energy for the Rydberg series is 3.338 eV at 300 K. For sample B, the direct gap is 3.434 eV with a BMS of 96 meV to render an electron density approaching 3.4u1019 cm-3 at room temperature. Which is comparable with the value (2.2u1019 cm-3) from Hall measurement. Power-dependent and temperature-dependent PL measurements verify and identify the properties of below-band-edge transitions including free exciton (FX), surface exciton (SX), bound exciton complexes (BECs), donor-acceptor pair (DAP), longitudinal optical (LO) phonon replicas of the BECs, and defect emissions. On the basis of the experimental analyses, physical- chemistry behaviors of the indium oxide nanowires are realized, and their potential applications are manifested.
Fig. 1. FESEM image of (a) cross-section view of sample A, (b) cross-section view of sample B, (c) top view of sample A and (d) top view of sample B for as-grown In2O3 thin-film nanowires. (e) Experimental TR and PL spectra of c-In2O3 thin-film nanorods at 20K. The inset depicted the possible band-edge scheme for the c- In2O3 thin-film nanowires by taking into account band-edge excitons, defects, and Burstein-Moss shift. (f) High-resolution PL spectra of c-In2O3 thin-film nanorods at 10 K. The six PL spectra were excited by different laser powers of 325nm-1%, 325nm-10%, 325nm-100%, 266nm-5%, 266nm-10%, and 266nm-100%. The inset used to verify that the near-band-edge emission features are well match between two samples.
[1] E. Burstein, Phys. Rev. 93, 632-633 (1954). [2] T. S. Moss, Phy. Soc. London Sect. B 67, 775-782 (1954).
300 P-12-07
Optical properties of pure and metabolically manipulated diatom frustules
Ankur Gogoi1,*, Lakhi Chetia2, Nirmal Mazumder3, Ratan Boruah2 and Gazi A Ahmed2 1Department of Physics, Jagannath Barooah College, Jorhat 785001, Assam, India 2Department of Physics, Tezpur University, Tezpur 784028, Assam, India 3Nanophysics, Italian Institute of Technology, Genoa, Italy *E-mail address: ([email protected])
Abstract: Optical properties of pure and metabolically manipulated tropical fresh water diatoms and their siliceous frustules have been studied. Scanning electron microscopy revealed the highly ordered nanoporous structure of the diatom frustules. It was observed that 97-98 % of the frustules were Si in the form of SiO2. The Fourier Transform Infrared spectroscopy analysis indicated the presence of “silaffin”, a class of silica precipitation proteins imbedded within diatom biosilica. The sample frustules emitted strong blue photoluminescence centered at 430 nm when samples were excited at UV wavelengths.
1. Introduction Diatoms are unicellular, microscopic, eukaryotic, photosynthetic algae that are found in both fresh water and marine environment and also in moist habitats. There are over 200000 species of these type of photosynthetic algae with world wide distribution and are responsible for 20-25% of global oxygen production by photosynthesis process. The morphogenesis of the peculiar cell wall (called frustule) architecture of diatom involves biomineralization of silica forming an array of patterns that ranges from submicrometric to nanometric scales. Such diatom frustules with their nanoporous structures exhibit peculiar optical properties which can be further enhanced by metabolic insertion of arsenic (As), germanium (Ge), titania (TiO2), etc. In this paper we report the change in optical properties of pure and metabolically manipulated diatom frustules with an attempt to find novel applications in optical nanobiotechnology. 2. Results and discussions Fresh water diatoms were grown in the laboratory using alternate sources of silicon (Ge, As, etc.). A cleaning procedure [1] was adopted to remove the external organic matrix covering the frustules. The morphology and elemental composition of the diatom frustules were analyzed respectively SEM, energy dispersive X-ray spectroscopy and X-ray diffraction analysis. Photoluminescence (PL) measurements of frustules were performed at room temperature. The PL intensity was taken at different excitation wavelengths. It was observed that the frustules emitted strong blue photoluminescence having a broad peak at around 430 nm when samples were excited UV wavelengths. Enhanced PL activity was observed in case of metabolically manipulated diatom frustules. The FTIR analysis indicated the presence of H-O-H bending of adsorbed water, Si-OH stretching or carboxyl (-CO) stretching for primary amides of residual proteins associated with diatom biosilica that might include “silaffin”, a class of silica precipitation proteins imbedded within diatom biosilica.
Figure 1. (a) SEM image of centric diatom frustules (Stephanodiscus hantzschii sp.) 3. Conclusion It is very important to know the way in which the diatom frustules and their nano-patterned structures interact with light for potential applications in next generation photonic and optoelectronic devices. The results obtained here may be useful for understanding the still unexplained extraordinary photosynthesis ability of diatoms. 4. References [1] A. Gogoi, et al. JQSRT 110, 1566–1578 (2009).
301 P-12-08
Enhanced Photoluminescence Emission in Hydrohalic Acid Treated MoSe2 Monolayers
Tsung Sheng Kao1, Hau-Vei Han1, Ang-Yu Lu2, Li-Syuan Lu3, Jing-Kai Huang2, Hao-Chung Kuo1,*, Wen-Hao Chang3, Lain-Jong Li2, and Yumeng Shi2 1Department of Photonics & Institute of Electro-Optical Engineering, National Chiao Tung University, Hsinchu 300, Taiwan 2Physical Sciences and Engineering Division, King Abdullah University of Science and Technology, Thuwal 23955-6900, Saudi Arabia 3Department of Electrophysics, National Chiao Tung University, Hsinchu 300, Taiwan E-mail address: [email protected]
Abstract: We demonstrate that the photoluminescence emission intensity of the CVD- grown MoSe2 monolayers can be effectively enhanced more than 30 times after a simple exposure process within hydrohalic acid vapors, providing the further insights of cost-effect manufacturing of atomically thin two-dimensional semiconductor materials.
Introduction Atomically thin semiconductor two-dimensional transition metal dichalcogenides (TMDCs) have attracted much attention recently due to their unique electronic and optical properties for future optoelectronic devices. To achieve the cost-effective and size-scalable TMDCs manufacturing, the chemical vapor deposition (CVD) is one of the most promising methods and can be readily applied in conventional semiconductor processes. However, the CVD-grown TMDC monolayers grown may produce unwanted structural defects, hindering the further practical applications. In this paper, we report that via a simple hydrohalic acid treatment (such as HBr), the trap-state emission in defect MoSe2 monolayers can be efficiently suppressed.[1] Meanwhile the neutral exciton and trion emission can be promoted during this p-doping process. The overall room-temperature photoluminescence (PL) emission intensity can be enhanced by a factor of 30. According to the results presented in this work, the HBr acid treatment employed in CVD-grown MoSe2 monolayers not only mends the point defects (Se vacancies) and oxidized Se defects, but also activate the distinctive trion and free exciton emissions, providing further insights of tailoring the exciton emission from TMDC monolayers. œesults and Discussions Monolayer MoSe2 was grown via the CVD process using the selenium and MoO2 powders as precursors. Figure 1(a) illustrates the optical microscope image of the fabricated MoSe2 on sapphire substrates. Monolayer MoSe2 exhibits a triangular shape with a lateral size up to 10 μm. The PL emission properties of the pristine and acid-treated MoSe2 monolayers at room temperature were characterized with an excitation laser beam of 532 nm, while the results are displayed in Fig. 1(b). From the spectral comparison, the main PL intensity peak of the HBr-treated MoSe2 monolayers occurs at around the photon energy of 1.53 eV which is similar to the one in the as-grown samples but with a great intensity enhancement more than 30 times. Such an improvement may result from the structural repairing of the defects generated in the MoSe2 monolayers after the acid treatment. The PL spatial intensity mappings shown in Fig. 1(c) and (d) give the light emission comparison between the pristine and treated MoSe2 respectively. As shown in Fig. 1(c), the PL signals are distinguished at the edge and weak or even absent toward the center of the as-grown MoSe2 monolayer, attributed to the charge defect-induced doping. Remarkably, after the HBr acid treatment, the light emission from the MoSe2 islands exhibits strong intensity increases and homogenous distributions as the results demonstrated in Fig. 1(d). The optical property modulations with the HBr treatment can be attributed to various reasons, including removing impurities, reducing the structural defects, and increasinggp the p-dopingpg to the MoSe2.[1]
Fig. 1. (a) Optical image of the as-prepared monolayer MoSe2 on sapphire substrates. (b) PL emission spectra of the pristine and HBr-treated MoSe2 samples at room temperature. (c) and (d) display the PL intensity mapping of the MoSe2 before and after acid treatment, respectively. References [1] H. -V. Han, A. -Y. Lu, L. -S. Lu, J. -K. Huang, H. Li, C. -L. Hsu, Y. -C. Lin, M. -H. Chiu, K. Suenaga, C. -W. Chu, H. -C. Kuo, W. -H. Chang, L. -J. Li and Y. Shi, “Photoluminescence enhancement and structure repairing of monolayer MoSe2 by hydrohalic acid treatment” ACS Nano, (Articles ASAP) DOI: 10.1021/acsnano.5b06960 (2015).
302 P-13-01
Plasmonic Photocatalyst for High Efficiency Photodecomposition with Spinning Optical Disk Reactor
Wen Ting Hsieh1*, I Da Chiang1, Yu Lim Chen1, Li Chung Kuo1, Min Lun Tseng1, Hao Ming Chen1,2, Chih Kai Chen2, Hung Ji Huang3, Ru Shi Liu2, and Din Ping Tsai1,4 1Department of Physics, National Taiwan University, No. 1, Sec. 4, Roosevelt Rd., Taipei 10617 Taiwan 2Department of Chemistry, National Taiwan University, No. 1, Sec. 4, Roosevelt Rd., Taipei 10617, Taiwan 3Instrument Technology Research Center, National Applied Research Laboratories, No. 20, R&D Rd. VI, Hsinchu 30076, Taiwan 4Research Center for Applied Sciences, Academia Sinica, No. 128, Sec. 2, Academia Rd., Taipei 11529, Taiwan *Author e-mail address: [email protected]
Abstract: Solar energy is a renewable energy source with great potential, furthermore, the rising issue of environmental pollution can be addressed by delicately designing a reactor utilizing visible and ultraviolet light energy to achieve high decomposition efficiency. An efficient and novel photocatalytic reactor for environmental treatment was fabricated with zinc oxide nanorods growing on the optical disk substrate as the photocatalyst. Plasmonic photocatalysis was also demonstrated to enhance the photodegradation efficiency.
1. Introduction Concern has been raised over the environmental contamination issue, environmental remediation and green energy has become one of the most high-profile topics in recent years. In this work, we developed an environmental benign process to decompose organic pollutants in aqueous solution with ZnO photocatalyst and silver nanopartics. We grew large-area ZnO nanorods on optical disk substrate by hydrothermal process, which can easily accompany with the spinning optical disk driver to significantly accelerate the surface photocatalytic degradation reaction[1]. In order to promote photocatalytic efficiency and make use of visible light, we deposit silver nanoparticles on the ZnO nanorods surface, see Fig. 1. (a, b). Noble metal nanoparticles dispersed onto semiconductor photocatalysts was considered as plasmonic photocatalysis possesses two prominent features—a Schottky junction and localized surface plasmonic resonance (LSPR), provided better charge separation and strong absorption of visible light, respectively[2]. UV and visible light source were fixed inside the reactor and employed during the reaction process for excitation of ZnO and LSPR, respectively. The photocatalytic activity was evaluated by the degradation of methyl orange (MO for short) as a model compound in aqueous solution.
Fig. 1. (a, b) The SEM images of silver-sputtered ZnO nanorods. The sizes of the silver nanoparticles range from 10 to 45 nm. (c) The relative concentration at different time of reaction with and without visible light source. C is the concentration of MO molecules at time t, and C0 is the initial concentration. 2. Results In the MO decomposition experiment, the variation of MO concentration directly displayed the photocatalytic ability of the ZnO nanorods. More than 13.9% MO was decomposed after a 20 minute treatment with visible light turned on, and the calculated chemical reaction rate constant was almost 50% larger than the one from experiment without any plasmonic effect, see Fig. 1. (c). These results indicated that the plasmonic effect is well demonstrated through the apparent enhancement of photocatalytic reaction rate. In this work we had combined the intelligent spinning optical disk reactor with the plasmonic photocatalytic nanostructure, both of which promote the reaction efficiency and the latter also accomplish to make further use of visible light region, which composed a major part of sunlight. As the optical disk is widely used and quite available material in our daily life, this work is very promised for the environmental treatment. 3. References [1] Y. L. Chen; L.C. Kuo; M. L. Tseng; H. M. Chen; C.K. Chen; H. J. Huang; R.S. Liu; D. P. Tsai, ZnO nanorod optical disk photocatalytic reactor for photodegradation of methyl orange,Opt. Express 21, 7240.(2013) [2] X.M. Zhang; Y. L. Chen; R.S. Lius; D. P. Tsai, Plasmonic photocatalysis Rep. Prog. Phys. 76, 046401.(2013)
303 P-13-02
GaAsSb Spacer Effect in Quasi Ttype-II InAs Coupled- QDs for IBSC Design
Yen-Ju Lin,1 Yun-Cheng Ku,1 David Jui-Yang Feng,2ġTzy-Rong Lin,3,4 Mao-Kuen Kuo1,* 1Institute of Applied Mechanics, National Taiwan University, Taipei, Taiwan 2Department of Electrical Engineering, National University of Kaohsiung, Kaohsiung, Taiwan 3Institute of Optoelectronic Sciences, National Taiwan Ocean University, Keelung, Taiwan 4Department of Mechanical and Mechatronic Engineering, National Taiwan Ocean University, Keelung, Taiwan E-mail address: [email protected]
Abstract: We designed a coupled quantum-dot (QD) structure with GaAsSb as spacer to form an intermediate band (IB) and calculated the electron and hole states by k.p method. Numerical results showed that the band alignment changes to be quasi type-II with 16% Sb. The AlAs electron blocking layer around the QD will help in strengthening the intraband transition in high energy range. The coupling QD structure with 8.5 nm GaAsSb spacer and 16% Sb concentration has best efficiency in the simulation.
1. Introduction A. Luque [1] provided a thought about intermediate band solar cell (IBSC), to insert an extra band inside the gap of the single gap solar cell. Quantum dots (QDs) has provoked intense interesting of research for past decades because of their atomic like density of states and three dimensions carrier confinement. Recently, the InAs QDs that are covered by a thin GaAsSb layer have attracted interests. InAs/GaAs quantum dot system with GaAsSb as strain reducing layer can change the band structure to be type-II [2]. In this paper, a coupled QD structure with GaAsSb as interlayer is investigated. 2. Method To estimate the performance of a QD solar cell with an IB, the electron states must be realized in the designed structure. The electron states are calculated using the Schrodinger equation. The energy states in the CB were calculated by the effective-mass method, and those in the VB were calculated by the 6 × 6 k.p method [3]. In the structural design, the strain profile is important; thus, the strain field was calculated using the elasticity. The piezoelectric effect of the QD material was also considered. The designed structure was treated as a unit cell to consider the formation of IB. Thus, periodic boundary conditions were used in our simulation. 3. Results and Discussion In the study, the structure of coupling QDs with GaAsSb as interlayer is designed. Electron-blocking AlAs layers are inserted below and above the coupled QD structure. The entire structure is considered as a unit cell to analyze the optical properties of the QD lattice and the IB. For Sb concentration of 16%, the top of the VB appears flat, which helps the hole wave function spread into the GaAsSb with a small part of the band inside the QD. For 2 nm-high QDs the maximum bandwidth of IB happens at GaAsSb thickness of 2.5 nm. It is because the stronger coupling effect between QDs. The efficiency simulation method is self-consistent drift-diffusion method for IBSC as Yoshida [4] but recombination terms are neglected for simplified. Designing of the device PIN junction is also the same as Yoshida. To make sure the intermediate band solar cell work, the quantum dot was pre-doped to achieve carrier balance via the intermediate band. The absorption strength for imtermediate band to conduction band is so weak that the araisement is not apparent. Then the increasment of efficiency is from the decrement of the effective bandgap. With lower bandgap, the structure can use more solar spectrum. If the effective bandgap is greater than GaAs, because of the weak intraband transition, it can’t compensate the loss in valenct band to conduction band transition then result the efficiency decrement. 4. Conclusion We designed a coupled QD structure with GaAsSb as spacer to form an IBSC. Using GaAsSb, the designed band structure was adjusted to have quasi-type-II alignment, helping to extend the absorption to infrared range and reducing the strength of absorption spectrum for transition between VB and IB. Because of the weak absorption coefficient for transition from intermediate band to conduction band, the main part of efficiency increase is from narrowing of the effective bandgap.
[1] A. Luque and A. Marti, Phys. Rev. Lett. 78(26), 5014-5017 (1997). [2] W. H. Chang, Y. A. Liao, W. T. Hsu, M. C. Lee, P. C. Chiu and J. I. Chyi, Appl. Phys. Lett. 93(3), 033107 (2008). [3] G. Liu and S. L. Chuang, Phys. Rev. B 65(16), 165220 (2002). [4] K. Yoshida, Y. Okada and N. Sano, J. Appl. Phys. 112, 084510 (2012).
304 P-13-03
Electrical and Optical Performances of MOS-Structure Si Solar Cells Based on Biasing and Plasmonics Effects
Ruei-Siang Sue, Wen-Jeng Ho*, Su-Han Weng, Chien-Wu Yeh, Jian-Cheng Lin Department of Electro-Optical Engineering, National Taipei University of Technology, No. 1, Sec. 3, Zhongxial E. Rd., Taipei (10608), Taiwan, R.O.C. *E-mail address: [email protected]
Abstract: Electrical and optical performances of the MOS-structure Si solar cells enhanced by applying voltage biasing on ITO-electrode and using plasmonics scattering of indium nanoparticles (In-NPs) were demonstrated. The plain ITO-electrode consisted of periodic holes with a diameter of 10 micrometer. The In-NPs were formed upon the surface of Si solar cells. Optical reflectance and external quantum efficiency (EQE) of the cells with and without the holes on the ITO-electrode, and with and without coated In-NPs are characterized. Furthermore, the efficiency enhancement of the MOS-structure Si solar cell with the voltage biasing of 2.5 V and In-NPs was obtained by 31.3%.
1. Introduction Solar energy is one of the most promising forms of renewable energy. Si-based solar cells with a variety of nanostructures have been developed for light trapping. Plasmonic effects have recently been applied to the problem of light trapping in silicon solar cells. MOS c-Si solar cells are a promising candidate for cost- effective photovoltaic devices because of the low temperature device process [1]. However, only a few studies have been conducted on the use of voltage biasing effects in MOS solar cells to enhance conversion efficiency [2], particularly with regard to the use of both biasing and plasmonic scattering effects with MOS solar cells. In this study, we experimentally demonstrated high conversion efficiency for a MOS structure Si solar cell by applying an external biasing voltage on the ITO-electrode and combined with indium nanoparticles (In-NPs) plasmonic scattering effects. The ITO-electrode was a plain-type or with periodic-holes-type. The improvements in photovoltaic performance derived from the applied biasing voltage and plasmonic scattering effect were exhibited by the increases in short-circuit current density (Jsc) and conversion efficiency (K). To examine the photovoltaic performance of the MOS-structure solar cell depending on with and without the biasing and plasmonic scattering effects, respectively, the photovoltaic J-V curves were measured and compared. The photovoltaic J-V curves of the MOS-structure solar cell with and without In-NPs as a function of the ITO biasing voltage are displayed in Fig. 1 and summarized in Table I. Under 0 V biasing, the MOS- 2 structure solar cell with periodic-holes-type ITO-electrode had a Jsc of 33.92 mA/cm , an open-circuit voltage 2 (Voc) of 545 mV, and an K of 13.55%, and had a Jsc of 36.39 mA/cm , a Voc of 545.6 mV, and an K of 12.95% for the cell with plain-type ITO. With In-NPs, an additional efficiency gain of 0.3-0.4% was obtained due to plasmonic scattering of In-NPs. However, under 2.5 V biasing, the enhancements of K of 26.8% without In- NPs and 31.3% with In-NPs were obtained for the MOS-structure solar cell with periodic-holes-type ITO- electrode. Thus, impressive photovoltaic performance enhanced by applying a biasing on the MOS-structure solar cells with periodic-holes-type an ITO-electrode and using plasmonics scattering of indium nanoparticles (In-NPs) can be achieved an more higher efficiency.. 2. References [1] R.B. Godfrey and M.A. Green, Appl. Phys. Lett., 34(11), 790-793 (1979). [2] V.Yu. Yerokhov, I.I. Melnyk, A.V. Korovin, Sol. Energy Material. Sol. Cells, 58, 225-236 (1999).
Table I Fig. 1 Photovoltaic J-V curves
305 P-13-04
Improved electroluminescence in a n-ZnO microrod/p- GaN-based light-emitting diodes with SiO2 inserting nanolayer
Sheng-Ming Hsu1, Kai-Hsiang Lin1, Zen-Jia Jiang1, Hsu-Cheng Hsu 1,2* 1Department of Photonics, National Cheng Kung University, 701 Tainan, Taiwan 2Advanced Optoelectronic Technology Center, National Cheng Kung University, 701 Tainan, Taiwan E-mail᧶[email protected]
Abstract: Zinc oxide (ZnO) has a wide band-gap (3.37eV) and also a large binding energy (60meV) which makes it valuable for short wavelength UV light emitting diodes (LED) and laser device. As a construction material, GaN are often chosen due to its little lattice mismatch and crystallographic similarity with ZnO. A ZnO microrod has an advantage in its hexagonal microcavity which provides a superior resonant cavity for the light confinement.[1] To enhance emitting intensity, an intermedium layer between the ZnO microrod and p-GaN thin film was employed. [2] Here, we demonstrate an intense UV polarized single horizontal n-ZnO microrod/p-GaN heterojunction light-emitting diodes with a sandwiched SiO2 layer as shown in Fig. 1. Rectifying diode-like behavior was demonstrated in the inset of Fig. 2. The LED with SiO2 layer shows a lower current at the same forward voltage. The electroluminescence intensity of the device with SiO2 layer is ten times stronger than that of the device without SiO2 layer as shown in Fig. 2. The optical field distributions were also simulated to confirm the effect of the optical confinement by inserting SiO2 layer. Three main peaks of EL emissions were observed under forward bias. The polarization-resolved EL was carried out to identify the origins of the carrier recombination.
without SiO 0.2 2 with SiO2
0.1
Current (mA) 0.0 -10 0 10 20 ITO Glass Voltage (V)
with SiO2 Ni/Au epoxy epoxy without SiO2 Current at 1.0 mA p-GaN Intensity (a.u.) u-GaN 40 nm SiO2 layer Sapphire 330 360 390 420 450 480 510 Wavelength (nm)
Fig. 1. The schematic diagram of n-ZnO microrod/p-GaN-based Fig. 2. The EL spectra of the LEDs with and without SiO2 layer. light-emitting diodes with SiO2 layer. The insets show The I-V characteristic of the LEDs in dark at RT
[1] C. X. Xu, J. Dai, G. P. Zhu, G. Y. Zhu, Y. Lin, J. T. Li, and Z. L. Shi, ȾWhispering-gallery mode lasing in ZnO microcavities炱 Laser Photonics Reviews. 8, 469 (2014). [2] H.Long, S. Li, X. Mo, H. Wang, Z. Chen, Z. C. Feng, and G. Fang. “Enhanced electroluminescence using Ta2O5/ZnO/HfO2 asymmetric double heterostructure in ZnO/GaN-based light emitting diodes” Optical Express 22, A883 (2014).
306 P-13-05
Numerical analysis of optical absorption effect in inverted small molecule solar cell
Ming-Yi Lin1*, Shang-Hsuan Wu2, Yia-Chung Chang2 and Chih-Wei Chu2 1Department of Electronic Engineering, Chung Yuan Christian University, Taoyuan 32023, Taiwan, R.O.C. 2Research Center of Applied Science, Academia Sinica, Taiwan 115, R.O.C. E-mail address: [email protected]
Abstract: The performances of inverted SMPV1:PC71BM solar cells are studied experimentally and theoretically. The absorption spectra for those with different thicknesses are simulated by RCWA method and compared with the experimental results. The power conversion efficiency of the inverted small molecule solar cell can reach 5.07%.
1. Introduction Organic photovoltaic (OPV) devices have great potentials for energy-generation applications in recent years due to its advantages such as low cost, flexibility, light weight, large area, etc. Among them, small molecule organic semiconductors have attracted increasing interest for preparing OPVs due to the advantages of its well-defined structures, facile synthesis and purification, and generally high Voc [1]. So far, conventional small molecule solar cells (SM-OPVs) based on a two-dimensional conjugated small molecule material SMPV1 blended with PC71BM have achieved 8.0% conversion efficiencies using a single bulk hetero- junction structure [1]. However, SM-OPVs based on inverted structure with high conversion efficiencies are rarely reported. It’s notice that inverted solar cells are generally relatively stable in air compared to conventional cells [2]. Therefore, the inverted SMPV1:PC71BM solar cells are studied experimentally and theoretically in this study. 2. Experiment and Method The layer structures of the devices consisted of glass substrate/ ITO/ ZnO / SMPV1:PC71BM /MoO3 /Ag (150 nm). The active layer (SMPV1:PC71BM (1:0.8 by weight)) was coated at various spinning rate, and annealed at 80oC for 10 minutes. The experimental results were further compared with the simulation data. Figure 1 shows the simulated optical absorption spectrum of the devices with various thicknesses (various spinning rate), calculating by rigorous coupled wave analysis (RCWA) method. The thicknesses of 210 nm and 80 nm both result in a strong absorption in active layer, implying that either the device with 210 nm or 80 nm should exhibit the best performance.
Fig. 1. Simulated absorption spectra of the devices with various thicknesses. 3. Results and Discussion In order to optimize the performance of inverted SM-OPVs, devices with various thicknesses (various spinning rate) were fabricated. Table I lists the device performance of inverted SM-OPVs. Although the device with the thickness of 210 nm (Sample A) shows stronger absorption than the device with the thickness of 80 nm (Sample D), the Sample D exhibits the better performance. Unlike polymer solar cells, SM-OPVs generally have shorter diffusion length which will greatly limit the thickness of the active layer. As a result, the efficiencies of the SM-OPVs with large thickness are usually poor.
Table I The device performance of inverted SM-OPVs Sample A Sample B Sample C Sample D Thickness (nm) 220 180 130 80
Voc (V) 0.85 0.83 0.83 0.88 2 Jsc (mA/cm ) 7.91 8.67 8.90 10.18 FF 0.41 0.41 0.40 0.56 PCE η (%) 2.76 2.96 2.94 5.07 4. References [1] H. Zhou, et al., “Conductive Conjugated Polyelectrolyte as Hole-Transporting Layer for Organic Bulk Heterojunction Solar Cells,” Adv. Mater. 26, 780–785 (2014). [2] Y. Liu, et al., “Solution-processed small-molecule solar cells: breaking the 10% power conversion efficiency, ” Sci. Rep. 3, 3356(2013).
307 P-13-06
Construction of graphene-based hybrid materials as the top electrodes of Si solar cells via spin coating process
Wei-Chen Tu*, Chang-Wen Fang, Wen-Chieh Lee, and Wu-Yih Uen Department of Electronic Engineering, Chung Yuan Christian University, Taoyuan, Taiwan (R.O.C.) E-mail address: [email protected]
Abstract: Developing highly efficient and cost-effective electrodes have been an important objective for textured and large-area applications of optoelectronic devices. Here, we propose the fabrication of graphene-based hybrid materials composed of graphene, Au nanoparticles and Ag nanowires as low-cost and indium tin oxide free top electrode of Si solar cell via spin coating process. Due to the uniformly spin-coated graphene along with the incorporation of Ag nanowires frameworks and plasmonic Au nanoparticles, the Si solar cell exhibits an improved efficiency of 9.51 % compared with cell using pure graphene as top electrode. Therefore, our results have great potential for integration into the next-generation industrial production of large-area, transparent and textured optoelectronic devices.
Introduction Graphene exhibits unique electrical and optical properties because of its 2D structure and energy dispersion, making it a promising candidate for future nanomaterial applications[1,2]. A single layer graphene is usually grown on transition metal substrates or SiC substrates via chemical vapor deposition (CVD)[3,4]. After the growth of graphene, it can be transferred to other substrates, providing a way toward future materials such as the replacement of indium tin oxide as the high transparent conductive electrode. However, graphene may be broken during transferred process especially on large area or textured surface. As a result, much effort has been focused on depositing graphene by graphene suspension via spin coating process to improve the uniformity of graphene on rough surface[5-7]. Unfortunately, the high resistance of graphene film as conductive electrode still limits the performance of optoelectronic devices. In this work, we fabricated pyramid Si solar cells with top conductive electrode using the combination of graphene flake, Au nanoparticles (AuNPs) and Ag nanowires (AgNWs) suspension via spin coating process. As shown in Figure 1, the SEM image reveals that the graphene, AuNPs and AgNWs hybrid materials were uniformly spin-coated on pyramid Si solar cell. With appropriate portion of graphene/AuNPs/AgNWs as top electrode of solar cell, an efficiency of 9.51 % was achieved which was obviously increased compared with 4.6 % bare Si solar cell using pure graphene as electrode. The characteristics of solar cells with different portion of graphene/AuNPs/AgNWs as top electrode are shown in Table I. Therefore, the graphene/ġ AuNPs/AgNWs hybrid material exhibits great potential as a low-cost and high transparent electrode for structured devices, such as solar cells and sensors.
Table I Characteristics of solar cells with different portion of graphene/AuNPs/AgNWs
Figure 1 Cross-sectional view of graphene-based material as top electrode of pyramid solar cell
References [1] K. S. Novoselov, A. K. Geim, S. V. Morozov, D. Jiang, Y. Zhang, S. V. Dubonos, I. V. Grigorieva and A. A. Firsov, Science, 306, 666 (2004). [2] A. K. Geim, and K. S. Novoselov, Nature Materials, 6, 183 (2007). [3] P. R. Kidambi, C. Ducati, B. Dlubak, D. Gardiner, R. S. Weatherup, M. Martin, P. Seneor, H. Coles, and S. Hofmann, Journal of Physical Chemistry C, 116, 22492 (2012). [4] P. R. Kidambi, B. C. Bayer, R. Blume, Z.-J. Wang, C. Baehtz, R. S.Weatherup, M.-G. Willinger, R. Schloegl, and S. Hofmann, Nano Lett. 13, 4769–4778 (2013) [5] D. S. Hecht, L. B. Hu, G. Irvin, Advanced Materials, 23, 1482 (2011). [6] Z. K. Liu, J. H. Li, Z. H. Sun, G. A. Tai, S. P. Lau, F. Yan, ACS Nano, 6, 810 (2012). [7] J. H. Li, L. Y. Niu, Z. J. Zheng, F. Yan, Advanced Materials, 26, 5239(2014).
308 P-13-07
Inexpensive Nano-textured Surfaces for Minimizing Top- surface Reflection in Optoelectronic Devices
Arpita Haldar1, M.Srinivas Reddy2 and R.Vijaya1,2 1Department of Physics, Indian Institute of Technology Kanpur, Kanpur 208016, INDIA 2Centre for Lasers and Photonics, Indian Institute of Technology Kanpur, Kanpur 208016, INDIA [email protected], [email protected], [email protected]
Abstract: A very effective lowering of top-surface reflection from a silicon (Si) wafer is demonstrated along with an increase in Si-solar cell efficiency by using patterned films of poly- dimethylsiloxane. These films are prepared by an inexpensive route of soft imprint lithography from a self-assembled photonic crystal as master. The measured trends in reflection for different patterning depths are supported by a rigorous coupled wave analysis.
1. Introduction The high refractive index (n = 3.4) of silicon (Si) leads to more than 30% of incident light being reflected or scattered from its surface, limiting the efficiency of Si-based optoelectronic devices. The large discontinuity in the refractive index at the air-Si interface can be bridged using efficient antireflection coatings on the top of devices so that the unwanted Fresnel reflection loss is avoided. Bio-inspired micro- or nano-architectures are widely studied as antireflective coatings because their effective refractive index varies gradually from air to the device material [1]. Here, we use an inexpensive and innovative method of patterning poly-dimethylsiloxane (PDMS) films to various values of patterning depth, and study the effect on top-surface reflection when these films are placed on a Si wafer. The lowering of top-surface reflection leads to an increase in efficiency of a Si-based solar cell. These effects are modeled using rigorous coupled wave analysis [2] of graded-index surfaces. 2. Description of work and Results and discussion The master mould for the soft imprint lithography is a self-assembled photonic crystal grown from polymer colloids with a mean diameter of 290 nm [3]. A thin layer of PDMS solution is poured on the mould, the film is cured and finally separated from the master mold. In Fig.1(a), the negative replica of the master mould obtained on a PDMS film is shown in an atomic force microcopy (AFM) image. By preparing the PDMS solution from three different (15:1, 10:1 and 7:1) ratios by weight of the base and curing agent of silicone elastomer (Sylgard 184, Dow Corning, USA), a steady decrease in viscosity of the PDMS solution is obtained. This has enabled an increase in patterning depth when the solution is poured and cured on the mould. Fig.1(b) depicts the reduction in reflectance (R) as a function of wavelength after patterning the PDMS film with three different patterning depths, while Fig.1(c) shows the effect at different incident angles for a patterning depth of 25 nm. Using a fully vectorial solution to the Maxwell’s equations for the structure in Fourier domain, the rigorous coupled wave analysis of the graded-index surfaces yields an excellent insight. The calculated contour plot in Fig.1(d) shows that by increasing the pattern depth, the reflectance can be lowered and can be reduced to less than 1% throughout the visible range by patterning the sample to a depth of ~ 100 nm. At larger depths, sharper are the edges of the pattern and thus one can expect an increase in the diffraction-induced transmission. This is seen by placing the patterned films on a Si solar cell and measuring its efficiency. The bare cell efficiency of 7.85% improves to 8.33% when a flat PDMS is placed on it and further increases very satisfactorily to 8.93%, 9.35% and 9.76% for patterning depths of 10 nm, 18 nm and 25 nm respectively.
(a) (b) (c) (d)
Fig.1 (a) AFM image of the patterned PDMS film showing the negative replica of the master mould. (b) Reflection measured at an incident angle of 100 from PDMS films of different patterning depths as well as for the unpatterned film. (c) Decrease in reflection at increasing angles of incidence after patterning the PDMS film to a depth of 25 nm. (d) Calculated variation of reflection at different patterning depths. The scale of R is shown on the right. Acknowledgements: The work was partially supported by IRDE, Dehradun, India under the DRDO Nanophotonics program (ST-12/IRD-124) and by DST, India under the India-Taiwan S&T co-operation project (GITA/DST/TWN/P-61/2014). References [1] H. K. Raut, V. A. Ganesh, A. S. Nair and S.Ramakrishna, Energy Environ. Sci. 4, 3779–3804 (2011). [2] M. G. Moharam and T. K. Gaylord, J. Opt. Soc. Am. 71, 811-818 (1981). [3] A.Haldar, M.S.Reddy and R.Vijaya, J. Phys. D: Appl. Phys. 48, 265103 (2015).
309 P-13-08
Photocatalytic hydrogen evolution efficiency of Si up to 13% by employing the cascading energy band structure and novel electrode design.
Hui-Chun Fu, Meng-Lin Tsai and Jr-Hau He* King Abdullah University of Science and Technology, Thuwal 23955-6900, Saudi Arabia E-mail address: [email protected]
Abstract: Renewable energy is one of the most important technologies in the world. Currently, photoelectrochemical (PEC) water splitting devices under the irradiation of sunlight have received much attention for the production of renewable hydrogen from water. In particular, Si- based solar cells are the most popular ones in the water splitting due to its abundancy, low cost, high efficiency, high stability, and well integration with the mature Si semiconductor fabrication technology. We design the cascading energy band structure in Si via doping for facilitating carrier separation and novel electrode structures for 360° light harvesting for hydrogen generation. Accordingly, a hydrogen evolution efficiency over 13% under AM 1.5 G light illumination has been achieved. Under acidic environment, the device can be operated up to 10 hours without significant deterioration. This multifunctional design provides the potential for the future development in energy market.
1. Bifacial photoelectrochemical cells (BPECCs)
3. Stabilityy Figure 1. (a) Band structure of BPECCs. (b)-(d) Photograph and SEM image on light harvesting (LH) side of BPECCs. (e)-(g) SEM image on Pt side of BPECCs with different thickness of Pt-coated. (h)-(j) AFM image with various thickness of Pt show the roughness of all condition. 2. PEC performancep
Figure 3. (a) J−E curves of the BPEC photocathodes with 5 nm Pt used as the HER catalyst for acidic (black line), neutral (red line), and basic (blue line) electrolytes. (b) Stability test results performed on a BPEC photocathodes. 4. 360° Omnidirectional Hydrogen Evolution
Figure 2. PEC performance of the BPECC photocathode in 1.0 M H2SO4 (aq) under simulated AM 1.5 G. (a) J-E curves of BPEC photocathode with different thickness of Pt-coated. The thickness of Pt deposited on n+ side has been optimized to 5 nm (b) bifacial illumination by 5 nm Pt coated.
Table 1. Characteristics of BPECC photocathodes with different thicknesses of Pt used as HER catalysts in a 1 M H2SO4 electrolyte.
Figure 4. (a) The angle-dependent measurement of (b) BPEC photocathodes as compared with (c) conventional PEC cells.
310 P-14-01
Nonlocal effects on the excitation of Core-shell type nearfield nano-laser
Y. Huang and L. Gao College of Physics, Optoelectronics and Energy of Soochow University, & Collaborative Innovation Center of Suzhou Nano Science and Technology, Soochow University, Suzhou 215006, China Jiangsu key Laboratory of Thin Films, Soochow University, Suzhou 215006, China Corresponding address: [email protected]
AbstractĻ We establish the spaser generation conditions for nonlocal core-shell compact plasmonic nanolasers in the long-wavelength limit. Dielectric/metal and metal/dielectric core-shell type nanoparticle laser are both considered. We show that different laser modes can be found due to the different plasmonic properties of core-shell nanoparticle structures. The required gain threshold and the gain refractive index become large generally when the nonlocality or spatial dispersion is taken into account. It may be of great important in the design of such kind of ultrasmall nanoparticle lases.
311 P-14-02
Dynamic Modulation of Surface Plasmon Nanolasers with Surface Acoustic Waves
Jheng-Hong Shih,1 Heng-Wei Kuo,1 Cong-Yuan Shih,2 Shu-Yu Chang,1 Chieh-Chun Chang,1 Keng-Yen Lee,1 Sin-An Lai,1 Pi-Ju Cheng,3 Jin-Chen Hsu,4 Tzy-Rong Lin1,2* 1Department of Mechanical and Mechatronic Engineering, National Taiwan Ocean University, Taiwan 2Institute of Optoelectronic Sciences, National Taiwan Ocean University, Taiwan 3Research Center for Applied Sciences, Academia Sinica, Taiwan 4Department of Mechanical Engineering, National Yunlin University of Science and Technology, Taiwan E-mail address: [email protected]
AbstractĻġWe present a scheme for the dynamic modulation of surface plasmon nanolasers [1-3] based on dynamic grating in a hybrid plasmonic-photonic cavity, consisting of a GaAs nanowire lying on an Ag substrate by a nanoscale SiO2 gap, with surface acoustic waves (SAWs), as shown in Figure 1. The dynamic grating is built up through the acousto-optic (AO) interaction [4-6] is developed theoretically by considering the interface deformation and refractive index change using the finite-element method. Because the hybrid cavity confines photonic and phononic excitations coupling optical to acoustic frequencies to enhance the AO interaction, the dynamic modulations of semiconductor plasmonic nanolasers through SAWs are achieved at telecommunication wavelengths. This study provides opportunities for various applications in tunable nanolasers, optical communication, and optomechanical devices.
Figure 1 Schematic diagram of surface plasmon nanolasers with surface acoustic waves
Keywords: Nanolasers; Surface Plasmon; Light-Matter Interaction; Acousto-Optic Coupling
[1] P.-J. Cheng, C.-Y. Weng, S.-W. Chang, T.-R. Lin, and C.-H. Tien, Optics Express 21, 13479–13491 (2013). [2] Y.-H. Chou et al, ACS Nano 9, 3978–3983 (2014). [3] B.-T. Chou et al, Scientific Reports, dio:10.1038/srep19887, accepted (2015). [4] J.-C. Hsu, C.-H. Lin, Y.-C. Ku, and T.-R. Lin, Optics Letters 38, 4050−4053 (2013). [5] T.-R. Lin, C.-H. Lin, and J.-C. Hsu, Scientific Reports 5, 13782-1–13782-11 (2015). [6] J.-C. Hsu, T.-Y. Lu, and T.-R. Lin, Optics Express 23, 25814–25826. (2015).
312 P-14-03
Room temperature lasing characteristics in GaN spiral and grating metal cavity
Yu-Hao Hsiao 1,Shu-Wei Liao 1, Wei-Chun Liao 1, Kuo-Ju Chen1, Min-Hsiung Shih1,2*, Hao-Chung Kuo1 1 Department of Photonics & Institute of Electro-Optical Engineering, National Chiao Tung University, Hsinchu 30010, 2 Research Center for Applied Sciences, Academia Sinica, Taipei 11529, Taiwan *E-mail address: [email protected]
Abstract: We demonstrated a metal-coated GaN spiral structure lasing at room temperature with the threshold power density of 0.017 kW/cm2 under circularly polarized pumping condition. The emission wavelength is approximately 363 nm. This phenomenon could be at-tributed to the surface plasmon polaritons.
1. Introduction In recent years, there are some researches about metamaterials or metasurfaces such as negative refraction [1], extraordinary transmission [2], cloaking [3], and quarter-wave plates [4]. The novel electromagnetic phenomena and the special optical properties of these metallic nanostructures could be attributed to the surface plasmonic effect. One of the most significant phenomena is the plasmonic chirality which can control the right- (R-) and left- (L-) handedness for different applications. 2. Results and Discussion The schematic diagram is shown in Fig.1(a). The gain medium of the GaN spiral structure laser was a 2 μm thick undoped GaN layer. Fig.1 (b) showed the SEM image of the GaN spiral structure after the deposition of metal. The diameter of the spiral structure is about 20μm. The period, width and the height of the spiral structure is about 1000 nm, 400 nm and 500 nm respectively. (a) (b)
ġ Fig. 1 (a) Schematic diagram of the metal-coated GaN spiral and grating structure. (b) The SEM image of the GaN spiral and grating structure after the deposition of metal.
Fig. 2(a) shows the measured spectra from a metal-coated GaN spiral structure above (red) and below (black) threshold under room temperature. A lasing peak wavelength around 363 nm is observed in the experiment. Fig. 2(b) shows the light-in and light-out curve of spiral structure under different polarized pumping condition. The metal-coated GaN spiral structure has a lower threshold pump power density about 0.017kW/cm2 when the pumping polarization is circular polarized. Furthermore, as shown in Fig. 2(c), we can find that the metal coated grating structure has a lower threshold pump power density about 0.016kW/cm2 when we use linear polarized pumping laser. On one hand, this phenomenon indicates that the threshold of the metal-coated GaN nanolaser depends on the type of structure if we use different polarized pumping source. On the other, Fig. 2(b),(c) also indirectly prove the metal-coated spiral structure exist a plasmonic circular polarized mode while the grating structure is easy to lase with linear polarized mode. 1.0 1.0 (a) 1.0 (b) (c) Circularly Polarized Pumping 2 Circularly Polarized Pumping 17.5W/cm Linearly Polarized Pumping Linearly Polarized Pumping 0.8 2 0.8 0.8 32.5W/cm
0.6 0.6 0.6
0.4 0.4 0.4 Intensity (a.u.) Intensity (a.u.) Intensity (a.u.) 0.2 0.2 0.2
0.0 0.0 0.0 360 365 370 375 380 0 5 10 15 20 25 0 5 10 15 20 25 30 35 40 45 Wavelength (nm) 2 2 Pump Power Density (W/cm ) Pump Power Density (W/cm ) Fig. 2 (a) Measured spectra from a metal-coated GaN laser by spiral structure below (black) and above (red) threshold; The Light-in and Light-out curve (L-L curve) under different polarized pumping condition of (b)metal-coated GaN spiral structure; (c)metal-coated GaN grating structure. In the conclusion, we successfully demonstrate met-al-coated GaN spiral laser with the lasing wavelength around 363nm at room temperature. The period, width and height of the metal-coated GaN spiral structure are 1000nm, 400nm and 500nm respectively. Compared with the met-al-coated grating laser, the spiral type structure has a lower threshold under circular polarized condition. This phenom-enon implies that the spiral type metal-coated nano laser exist a circular polarized mode. We believe that the met-al-coated GaN spiral laser would be a small volume and more practical circularly polarized laser in the future. 3. References [1] D. R. Smith, J. B. Pendry, M. C. K. Wiltshire, “Metamaterials and negative refractive index,” Science, 305 (2004) no. 5685 pp. 788-792. [2] W. L. Barnes, A. Dereux, and T. W. Ebbesen, “Surface plas-mon subwavelength optics,” Nature (London), 424 (2003) pp. 824-830. [3] D. Schurig, J. J. Mock, B. J. Justice, S. A. Cummer, J. B. Pendry, A. F. Starr, D. R. Smith, “Metamaterial Electromag-netic Cloak at Microwave Frequencies,” Science, 314 (2006) no. 5801 pp. 977-980. [4] N. Yu, F. Aieta, P. Genevet, M. A.Kats, Z. Gaburro, and F. Capasso, “A Broadband, Background-Free Quarter-Wave Plate Based on Plasmonic Metasurfaces,” Nano Lett., 12 (2012) 6328−6333.
313 P-15-01
Plasmon-Enhanced Local Field of Coupled Silver Islands
Hao-Ting Hung1, Mao-Kuen Kuo1, and Jiunn-Woei Liaw2,3,4* 1Institute of Applied Mechanics, National Taiwan University, Taiwan 2Department of Mechanical Engineering, Chang Gung University, Taiwan 3Center for Biomedical Engineering, Chang Gung University, Taiwan 4Medical Physics Research Center, Institute for Radiological Research, Chang Gung University/Chang Gung Memorial Hospital, Taiwan E-mail address: [email protected]
Abstract: The plasmon-enhanced local field around multiple adjacent silver islands (SIs) is studied. We use the multiple multipole (MMP) method to analyze the electric field of two or three nearby SIs. Results show that the enhancement factor of the coupled nanostructures on the local electric field is larger than that of a single SI, particularly in the gap zone. Additionally, the performance is broadband. It implies that a denser SI film is more useful for the metal enhanced fluorescence (MEF) or surface enhanced Raman scattering (SERS).
1. Introduction Recently, a silver island (SI) film has attracted a lot of attention for the applications of metal enhanced fluorescence (MEF) and surface enhanced Raman scattering (SERS) [1-3]. The previous study has shown that the local-electric-field enhancement of SI film is significantly strong and broadband. In particular, the merit of SI film lies in the local-electric-field enhancement in the gap zone between two or three adjacent SIs; the former forms a coupled dimer and the latter a trimer [3]. In the paper, we theoretically investigate the coupling performances of dimers or trimers with different gap sizes on the local-electric-field enhancement. 2. Method In the simulation, SI is modeled as an oblate spheroid. First, we used the multiple multipole (MMP) method to analyze the scattering and absorption cross-section spectra of a single, two or three adjacent SIs irradiated by an obliquely incident plane wave [4-6]. Subsequently, the near field of these coupled nanostructures in relevance to the gap size was investigated at the plasmon band. Moreover, the radiative and nonradiative powers of an electric dipole, modelling an emitting molecule, were calculated to analyze the apparent quantum yield of an excited molecule’s emission affected by the coupled nanostructure. Finally, we analyzed the overall enhancement factors of the coupled nanostructure on MEF at different emission wavelengths. 3. Result and Discussion Compared to a single SI, our numerical results show that the spectra of scattering and absorption of multiple coupled oblate spheroids are broadband. Moreover, the local-electric-field enhancement of the coupled SIs is more pronounced than that of a single SI. As the gap size decreases, the enhancement of a dimer or trimer increases and the bandwidth increases due to the coupling effect. The results imply that a denser SI film can enhance the local-electric-field more as irradiated by a light and that its MEF performance is available for a variety of molecules with different excitation and emission spectra. 4. Conclusion The wavelength-dependent local-electric-field enhancement of coupled nanostructure (a dimer or trimer) was studied theoretically by using MMP method. The numerical results show that the enhancement in the gap zone of a dimer or trimer is pronounced and broadband. Within the gaps in between adjacent SIs, which are hot spots, the local electric field can be enhanced significantly. As the gap size decreases, the enhancement of a dimer or trimer increases and the bandwidth increases. Because of the merit, a denser SI film can be applied to the MEF and SERS.
[1] K. Aslan, S. N. Malyn, and C. D. Geddes, Chem. Phys. Lett. 453, 222–228 (2008). [2] Y. Fu, J. Zhang, and J. R. Lakowicz, Langmuir 29, 2731-2738 (2013). [3] M. L. Tseng, B. H. Leu, P. Y. Li, K. S. Chung, and H. P. Chiang, Plasmonics 10, 1301-1305 (2015). [4] J.-W. Liaw, H.-Y. Wu, C.-C. Huang, and M.-K. Kuo, Nanoscale Res. Lett. 11, 26 (2016). [5] J.-W. Liaw, C.-S. Chen, J.-H. Chen, and M.-K. Kuo, Optics Express 17(16), 13532-13540 (2009). [6] J.-W. Liaw, C.-S. Chen, and J.-H. Chen, J. Quant. Spectrosc. Radiat. Transfer 111, 454–465 (2010).
314 P-15-02
Optimization of the Gain curve of the InGaN Blue Laser Diode
Yen Chang Chen,† Te-Jen Kung†, Yun-Chorng Chang‡ and Yuh-Renn Wu, *† † Institute of Photonics and Optoelectronics and Department of Electrical Engineering, National Taiwan University, Taipei 10617, Taiwan ‡1 Research Center for Applied Sciences, Academia Sinica, Taipei 11529, Taiwan Email address: [email protected]
Abstract: The gain curve of InGaN laser diode is simulated and optimized by solving the Poisson and drift diffusion equation and Helmholtz Equation for the cavity mode. The optimized quantum well number of laser diodes is limited to be less than 4 due to imbalance of carrier injection. In addition, the composition of the Indium composition in the quantum well should be different because of the band bending effect.
315 P-15-03
Spectral Switches with Fibers and Wide Band Source
Tsung-Han Hsieh, Hsun-Ching Hsu and Pin Han* Graduate Institute of Precision Engineering, National Chung Hsing University, Taichung 402, Taiwan * Corresponding author email: [email protected]
Abstract: A novel and simple configuration using single mode fiber and glass interference is used to realize the spectral switch. The results agree well with the theoretic calculations and it has the potential to be used as ranger tool by measuring the interference spectrum.
1. Introduction Spectral switch (SSW) is now a well-known effect, which discusses the discontinuous spectral shift for a broad band light source (BBS). There are many mechanisms to produce SSW, including aperture diffraction [1], nonlinearity [2] and surface plasmons [3] etc. SSW also has many potential applications, such as the data transmission, spectra manipulations. In this work, a novel and simpler scheme, utilizing the single mode fiber (SMF) and the Fresnel reflection, is employed to produce SSW. And its application to measure the distance is verified by the experimental results. 2. Theory and Experimental Setup Figure 1 illustrates the setup, where a piece of glass is placed in front of a SMF and the distance between them is d. A BBS with bandwidth about 100 nm, as shown in Fig. 2, is coupled into the fibber, part of the light is reflected back into the fiber and some of them, after transmitting to air, will be reflected back to fiber by the air- glass interface. These two reflected beam will interfere and the interfered spectrum can be obtained through the coupler and shown on the optical spectrum analyzer (OSA), as in Fig. (3). Using the spectral interference law [4] S1c OOvSd 0 ^`os 4 SO , (1)
where S()O is the detected spectrum, S(0)()O is the original spectrum, and O is the wavelength. Figure 4(a)-(c) show the normalized interference spectrum for d = 10.66, 10.69, 10.74 um respectively. First, we find that the experimental curve (solid line, E) is very closed to the theoretical one (dashed line, T), and S(0)( O ) is denoted as dotted line, L. Second, as shown in the top of the figures, the maximum of interference spectrum S( O ) is red shifted in (a), with respected to S(0)()O ; then the two peaks of S()O almost have the same heights in (b); in (c) the spectral shift is a blue shift. This is the famous SSW effect and here we use a simple configuration to realize it.
Fig. 1. Two reflected beams from Fig. 2. The broad-band light source.! Fig. 3. The Experimental setup.! the interface.!
()a ()b ()c
Fig. 4(a). Spectrum for d = 10.66 um. Fig. 4(b). Spectrum for d = 10.69 um. Fig. 4(c). Spectrum for d = 10.74 um 3. Conclusions A simple configuration is used to produce SSW and the interference spectrum can be controlled by adjusting the air gap. Since the detected spectrum is very sensitive to the gap distance, it has the potential to be used as a real time distance measurement tool, without counting the accumulated fringes as in Michelson interferometer. 4. References [1] Pin Han, “Spectral shifts with polarization control” JOURNAL OF OPTICS, 15, p. 105710 (2013). [2] Pin Han “All optical spectral switches” Optics Letters Vol. 37 No. 12 pp. 2319-2321 (2012). [3] Pin Han, “Near-field surface plasmon effects on Au-double-slit diffraction for polychromatic light” Nano. Res. Lett., Vol. 9-561 (2014) [4] M. Born, and E. Wolf, “Principles of optics”, Cambridge University Press, New York. p. 587 (1999).
316 P-15-04
Avoided Resonance Crossings in Plasomonic Nanodisks with Near-field and Far-field couplings
Shih-Hui Gilbert Chang*, Chia-Yi Sun Department of Photonics, National Cheng Kung University, Tainan, Taiwan [email protected]
Abstract: Avoided resonance crossings in plasmonic nanodisk structures due to near field and far field couplings were numerically studied. Near field coupling in disk dimmer leads to both energy and linewidth anti-crossing by varying the top disk diameter. Far field coupling in double layered disk array with gap size close to Fabry Perot resonant condition leads to linewidth anti-crossing but energy crossing by varying the gap size and the diameter of one disk. Asymmetric transmission spectrum from different side of the double layered disk arrays shows the disappearing of Fabry-Perot resonant mode and perfect absorption properties.
Avoided resonance crossing is a general physical phenomenon describing the splitting behavior in a coupled system. For example, in dielectric hexagonal dielectric resonators, the degenerated triangular resonant modes exhibit energy level and linewidth anti-crossing by varying the height of one hexagonal edge. One of the modes leads to longer life time with higher quality factor. In this paper, we show that similar anti-resonance crossing behavior can be observed in plasmonic nanostructures due to either near field or far field coupling. Near field coupling in disk dimmer leads to both energy and linewidth anti-crossing by varying the diameter of top disk as shown in Fig. 1. Far field coupling in double layered disk array with gap size close to Fabry-Perot resonant condition leads to linewidth anti- crossing but energy crossing by varying the gap size and the diameter of one disk. Asymmetric transmission /reflection /absorption spectra from different side of the double layered disk arrays with r1 z r2 show the disappearing of Fabry-Perot resonant mode and perfect absorption properties in Fig. 2. Its linewidth also shows the anti-crossing behavior by varying the gap size. The observed avoided resonance crossings in plasmonic nanostructure would lead to higher Q factor for future sensing applications.
Fig.1 Avoided Resonance Crossing in disk dimmer by varing the radius of top disk r1.
Fig. 2 Asymmetric absorption spectrum for double layered disk arrays with r1 z r2 by varying the gap size
[1] Q. Song, L. Ge, J. Wiersig, and H. Cao Phys. Rev. A. 88, 023834 (2013).
317 P-15-05
High-Resolution Study of Dielectric-Substrate Supported Surface Plasmon Waveguides
Hsuan-Hao Liu, Hsiang-Peng Chen, and Hung-chun Chang Graduate Institute of Photonics and Optoelectronics, Graduate Institute of Communication Engineering, and Department of Electrical Engineering, National Taiwan University, Taipei 10617, Taiwan E-mail address: [email protected]
Abstract: Surface plasmon waveguiding on metal stripes and nanowires supported by dielectric substrate is analyzed by a finite element method with high mesh resolution to reveal peculiar modal characteristics. Leaky modes are in particular studied.
1. Introduction Various structures for surface plasmon (SP) waveguides or plasmonic waveguides have been proposed and studied with the goal of achieving mode-field confinement beyond the diffraction limit [1]. Two simple but basic structures are considered in this paper: the metal stripe on top of a dielectric substrate and the circular metal nanowire having a similar substrate. The former has been analyzed in detail using a finite difference method [2], showing its leaky modes possess longer propagation distances than the bound modes. The leaky modes are with mode-field profiles mainly on top of the stripe, while those of the bound modes are below the stripe and mainly in the substrate. Due to the current computer capacity compared with that in the work of [2] conducted a decade ago, we are able to design a mode solution scheme with more than a half million field-quantity unknowns such that much detailed waveguide modal characteristics can be revealed. Our solution method is an in-house developed full-vector finite-element imaginary-distance beam-propagation method (FV-FE-ID-BPM) solver [3]. By using fine enough spatial mesh resolution, the obtained field profile in the cross-section of the stripe reveals the coupling of the air-metal SP and the metal-substrate SP in the mode. High-resolution calculations also demonstrate clearly the field leakage phenomena in the leaky modes. As for the structure of a circular metal nanowire on top of a dielectric substrate, its modal characteristics have only been investigated in detail recently [3, 4]. However, only the mode guided near the dielectric interface below the nanowire was considered. Our study concludes that this mode is the counterpart of the bound mode of the stripe waveguide and thus there might exist the leaky mode corresponding to that of the stripe waveguide. This is indeed the case as demonstrated in the following numerical results. 2. Representative numerical results We consider a silver nanowire of 60-nm radius sitting on silica with index of 1.45 at the wavelength of 500 nm. The complex permittivity for silver is adopted from [6]. The FV-FE-ID-BPM calculated Re[Ey] profile of the leaky mode is shown in Fig. 1. The large computational window with 2-Pm thick perfectly matched layer (PML) is employed to reveal the clear leaky field in the substrate, as seen in Fig. 1(a). Two enlarged versions to show the field profile near the nanowire are given in Fig. 2(b) and (c). As in the stripe waveguide, the major part of the leaky-mode field resides in the air above the nanowire. We have found that this leaky mode has larger loss or smaller propagation length than the bound mode, which is different from the case of the stripe waveguide.
(a) (b) (c) Fig. 1. (a) Re[Ey] profile of the leaky mode of a silver nanowire of 60-nm radius sitting on silica at the wavelength of 500 nm. (b) and (c) show enlarged versions. 3. References [1] D. K. Gramotnev and S. I. Bozhevolnyi, Nat. Photonics 4, 83–91 (2010). [2] R. Zia, M. D. Selker, and M. L. Brongersma, Phys. Rev. B, 71, 165431 (2005). [3] S. M. Hsu, H. J. Chen, and H. C. Chang, Proc. SPIE, 5623, 316–324 (2005). [4] Y. Wang, Y. Ma, X. Guo, and L. M. Tong, Opt. Express, 20, pp. 19006–19015 (2012) [5] Q. Li and M. Qiu, Opt. Express, 21, 8587–8595 (2013). [6] P. B. Johnson and R. W. Christy, Phys. Rev. B, 6, 4370–4379 (1972).
318 P-15-06
Energy structure and radiative lifetimes of InGaN/AlN quantum dots
I.A. Aleksandrov, K.S. Zhuravlev Rzhanov Institure of Semiconductor Physics SB RAS, Novosibirsk, Russia E-mail address: [email protected]
Abstract: Emission energies and radiative lifetimes of InxGa1-xN/AlN quantum dots have been calculated in 6-band kp approximation for varying quantum dot height and indium content. Emission energy and radiative lifetimes of InxGa1-xN/AlN can be varied in wide ranges by varying quantum dot height and indium content.
III-Nitride quantum dots (QDs) are promising for development room-temperature single-photon emitters. It has been shown recently that GaN quantum dots in AlN matrix are suitable for ultraviolet room-temperature single-photon emitters [1, 2]. Using InxGa1-xN QDs in AlN matrix can allow to reach visible and infrared range of emission, including telecommunication wavelengths of 1.3 and 1.55 mkm. InxGa1-xN/AlN QDs have large band offsets which prevent nonradiative losses of charge carriers even at elevated temperatures. InGaN/AlN QDs is relatively weakly studied in comparison with GaN/AlN QDs. It has been shown that InGaN QDs in AlN matrix can be grown by molecular beam epitaxy [3] and metalorganic chemical vapor deposition [4]. In this work we have calculated energy levels and radiative lifetimes for InxGa1-xN/AlN quantum dots. Calculations have been carried out 6-band kp approximation for quantum dots with varying height and indium content. The shape of the QDs supposed to be truncated hexagonal pyramid located on a wetting layer. QD height to diameter ratio supposed to be 0.2, wetting layer thickness was taken to be 0.8 nm. Material parameters were taken from refs [5-7]. Emission energy of the QDs decreases from 2.48 eV to 0.68 eV with increasing QD height from 1.5 to 3.5 nm for indium content x=0.2. Emission photon energy of a QD with height of 1.5 nm varies from 3.39 eV to 0.02 eV with indium content varying from 0 to 1 (fig. 1). Radiative lifetime increases with increasing QD height and indium content. According to our calculations for emission at telecommunication wavelength of 1.55 mkm InxGa1-xN/AlN QD should have indium content of 0.29, 0.45 and 0.67 for QD heights of 2.5, 2.0 and 1.5 nm, correspondingly.
Fig. 1. Dependence of emission photon energy (left graph) and radiative lifetime (right graph) on indium content x in InxGa1-xN/AlN quantum dots for different quantum dot heights.
[1] M. J. Holmes, K. Choi, S. Kako, M. Arita, and Y. Arakawa, Nano Lett. 14, 982 (2014). [2] S. Kako, C. Santori, K. Hoshino, S. Gotzinger, Y. Yamamoto, Y. Arakawa, Nature Mat. 5, 887 (2006). [3] C.-H. Shen, H.-W. Lin, H.-M. Lee, C.-L. Wu, J.-T. Hsu, S. Gwo, Thin Solid Films 494, 79–83 (2006). [4] L. S. Wang, S. J. Chua, K. Y. Zang, and S. Tripathy, phys. stat. sol. (c) 0, 2082–2086 (2003). [5] P. Rinke, M. Winkelnkemper, A. Qteish, D. Bimberg, J. Neugebauer, andM. Scheffler, Phys. Rev. B 77, 075202 (2008). [6] F. Bernardini, in: Nitride Semiconductor Devices: Principles and Simulation, edited by J. Piprek (Wiley- VCH, Weinheim, 2006). [7] I. Vurgaftman and J. R. Meyer, in: Nitride Semiconductor Devices: Principles and Simulation, edited by J. Piprek (Wiley-VCH, Weinheim, 2006).
319 P-15-07
One-dimensional polariton solitons and localized states in disordered semiconductor microcavities
Ting-Wei Chen1, Wen-Feng Hsieh2, and Szu-Cheng Cheng1,* 1 Department of Optoelectric Physics, Chinese Culture University, Taipei 11114, Taiwan, R. O. C. 2 Department of Photonics and Institute of Electro-Optical Engineering, National Chiao Tung University, Hsinchu 30010, Taiwan, R. O. C. E-mail address: [email protected], [email protected]
Abstract: This paper presents numerical studies of cavity polariton solitons (CPSs) in a resonantly-pumped semiconductor microcavity. In the simulation, the exciton under a Gaussian defect is taken into consideration in the mean-field model for excitons strongly coupled to the cavity photons. In the bistable regime, with proper incident wave vector and pump intensity, bright and/or dark cavity solitons are found to bifurcate from the homogeneous solutions of the polariton condensate. Furthermore, the existence range of CPSs in terms of the momentum and intensity of the external pump beam is also investigated for different pump detuning.
320 P-15-08
Modulated Light Transmission through a Subwavelengthġ Slit at Early Stage
1 2 3,* Jian-Shiung Hong, Alexander Ewen Chen, and Kuan-Ren Chen 1Department of Photonics, National Cheng Kung University, 1 University Road, Tainan 70101, Taiwan, ROC 2Department of Electrical Engineering, The Pennsylvania State University, University Park, PA 16802, USA 3Department of Physics, National Cheng Kung University, 1 University Road, Tainan 70101, Taiwan, ROC E-mail address: [email protected]
Abstract: The early dynamics of light transmission through a subwavelength slit in a finite- difference time-domain simulation shows that the amplitude of the transmitted light can be modulated. This underneath physics is studied with a new model. Besides academic importance, this phenomenon and its understanding is essential to photonic applications utilizing short temporal pulses in a width of several to tens of light periods.
1. Introduction The extraordinary optical transmission through a subwavelength hole array in a metallic film [1] inspires researchers in the area of plasmonics to explore the possibility of applications, such as those discussed in ref. [2]. A single subwavelength slit is the simplest configuration to understand the fundamental mechanism [3-5]. To the best of our knowledge, there is no discussion about the dynamics of the transmission at the early stage. In an FDTD simulation, we find that the transmitted field through the configuration can be modulated at the early stage. A new model is developed based on Fabry-Pérot-like resonance to interpret. Besides academic importance, this study may be applicable to photonics with short laser pulses [6]. 2. Modulated light transmission We show in Fig. 1 the simulation history of the transmitted electric field through a subwavelength slit of width 40 nm in different film thicknesses when the wavelength of the incident wave is 560 nm. It is found that the amplitude of the transmitted light can be modulated. A new analytical model is developed to interpret. Each light period of the incident light is considered here as an individual unit. The unit is partially transmitted through the slit as the first subunit. The portion reflected from the exit interface travels a round trip in the slit and then partially transmitted out as the second subunit. If the round trip time trt is equal to one light period, the second subunit begins at the end of the first one. There may be a gap in time between these two subunits when the round trip time is longer. This process repeats so that this unit produces a subunit train. The transmitted light then results from the superposition of the subunit trains of each unit. We show in Fig. 1 that, when the round- trip time is an integer multiple of the light period, the amplitude of the transmitted light is modulated in a period of the multiple number. The modeling results agree well with those from the corresponding simulation.
Fig. 2 The results from simulation and modeling when h = 205 nm (a), 470 nm (b), and 730 nm (c), respectively.
Suppose that the temporal full-width at half-maximum of a short pulse is defined as Δt. When Δt #trt, the subunits partially overlap so that the temporal width of the observed field can be effectively increased [5]. When Δt is short enough, the pulse could be seen as a wave unit, and its subunits can even barely interfere with each other. For a real metal, the plasmonic effect can disperse the wave. However, since similar Fabry-Pérot-like resonance exists [7], the key physics revealed by our modeling should still be valid. 3. Summary A new analytical model was proposed to study the modulated light transmission through the slit at early stage. When trt is a multiple of one light period, the temporal gap is filled by the following wave unit(s) to form the modulation. Possible applications for those with pulsed laser and the plasmonic effect are discussed.
[1] T. W. Ebbesen, H. J. Lezec, H. F. Ghaemi, T. Thio, and P. A. Wolff, Nature 391, 667-669 (1998). [2] C. Genet and T. W. Ebbesen, Nature 445, 39-46 (2007). [3] E. Betzig, A. Harootunian, A. Lewis, and M. Isaacson, Appl. Opt. 25, 1890-1900 (1986). [4] Y. Takakura, Phys. Rev. Lett. 86, 5601-5603 (2001). [5] M. Mechler, O. Samek, and S. V. Kukhlevsky, Phys. Rev. Lett. 98, 163901 (2007). [6] J. S. Hong, A. E. Chen, and K. R. Chen, Opt. Express 23, 9901-9910 (2015). [7] S. Astilean, P. Lalanne, and M. Palamaru, Opt. Commun. 175, 265-273 (2000).
321 P-16-01
Dual dark polariton switch in a triple quantum well microcavity
Tao Wang1,2,3, Zhong Chang Zhuo1,2 and Xue Mei Su1,2,* 1State Key Lab of Superhard Materials, College of Physics, Jilin University, Changchun 130012, China 2Key Lab of Coherent Light, Atomic and Molecular Spectroscopy, Ministry of Education, Changchun 130012, China 3College of Physics, Tonghua Normal University, Tonghua 134000, China
Abstrct: Tunneling induced transparency between intersubband transitions are investigated to generate two dark polaritons in a microcavity that several periods of asymmetric triple- quantum wells are embedded in. Two dark polaritons can be created by the intracavity coherent effects, and can be switched by using an external laser. The group time delay of this system is calculated to obtain the slow optical polaritons. The results are used as all- optical switching and buffering for the two dark polaritons.
PACS numbers: 42.50.Pq, 42.50.Gy, 32.80.Qk
322 P-17-01
Numerical investigation on soliton temporal and spectral compression in a temperature-tuned SOI waveguide
Chao-Yu Hsieh and Chen-Bin Huang* Institute of Photonics Technologies, National Tsing Hua University, 101 Sec. 2 Kuang Fu Road, Hsinchu 30013, Taiwan *Corresponding author: [email protected]
Abstract: We numerically study the adiabatic soliton temporal/spectral compression in a silicon-on-insulator (SOI) waveguide of 750 Pm length using finite-difference-time-domain method (FDTD). The temporal/spectral compression is accomplished through temporal modulation to the refractive indices.
1. Introduction Soliton temporal compression using a dispersion-decreasing fiber (DDF) is a commonly deployed method in obtaining fs optical pulses. Interestingly but receiving less attentions, soliton spectral compression can be achieved using the reverse process, by allowing short pulse propagation in a dispersion-increasing fiber (DIF) [1]. However, DDF/DIF are typically long in lengths (few km) and are non-reconfigurable. It is therefore very attractive to achieved tunable temporal/spectral compressions, all on a chip. In this work, we numerically address the first attempt in realizing dynamically tunable soliton temporal/spectral compressor with a length of only 750 Pm. 2. Dispersion relation of the Channel Waveguide Figure 1(a) shows the geometry and mode profile of our SOI waveguide. Figure 1(b) shows the dispersion relation of the SOI channel waveguide with height = 350 nm and width = 450, 500, 550 nm (blue line, green line and red line, respectively). The green trace exhibits small anomalous dispersion and in addition a flattened relation that is most suitable for our needs.
(a) (b)
Fig. 1. (a) The geometry of the channel waveguide. (b) Dispersion relation of the SOI channel waveguide with height = 350nm and width = 450, 500,550nm. Inset shows the source spectrum. 3. Adiabatic soliton temporal and spectral compression Figure 2(a) shows the temporal evolution of the pulse propagation with a ramp refractive index change = -0.15. We can see that the pulse is gradually compressed with thinner width and higher pulse peak, confirming adiabatic soliton compression. Figure 2(b) shows the soliton spectral compression result with a ramp index change = +0.15. We note under a linear temporal index modulation, the spectrally compressed peaks also undergoes a translation in the absolute frequency, which adheres to the Fourier transformation relationship. (a) (b)
Fig. 2. Temporal/frequency evolutions and input/output profile for: (a) temporal compression and (b) spectral compression.
[1] H. P. Chuang and C. B. Huang, "Wavelength-tunable spectral compression in a dispersion-increasing fiber," Opt. Lett. 36, 2848 (2011).
323 P-17-02
Compact Low Loss Design of SOI 1x2 Y-Branch Optical Power Splitter with s-bend Waveguide and Study on the Variation of Transmitted Power with Component Width
NagaRaju Pendam1* and C.P.Vardhani2 1 Research Scholar, Dept of Physics, Osmania University, Telangana, Hyderabad, 500007 India. 2 Assistant Professor, Dept of Physics, Osmania University, Telangana, Hyderabad, 500007, India. * NagaRaju Pendam, +919908437460, [email protected]. C.P.Vardhani, +919391111182, [email protected]
Abstract: A simple technology–compatible design of silicon-on-insulator based 1×2 optical power splitter is proposed. For developing large area Opto-electronic Silicon-on-insulator (SOI) devices, the power splitter is a key passive device. The SOI rib- waveguide dimensions (height, width, and etching depth, refractive indices, length of waveguide) leading simultaneously to single mode propagation. In this paper a low loss optical power splitter is designed by using R Soft cad tool and simulated by Beam propagation method, here s-bend waveguides for symmetrical and asymmetrical designs proposed. We concentrated by changing the width of the waveguide for symmetrical and asymmetrical waveguides and observing transmitted power, effective refractive index in the designed waveguide, and choosing the best simulated results and fabricated on silicon-on insulator platform. In this design 1550nm free spacing is used. From the simulated results, we observed symmetrical optical power splitter transmitted power as 0.985W, and for asymmetrical optical power splitter transmitted power as 0.9561W.
Keywords: Beam Propagation Method, Optical Power Splitter, Rib waveguide, Transmitted power.
324 P-18-01
Mode Characteristic of Second-Harmonic Generation in a Plasmonic Two-Wire Transmission Line
Hsin-Wen Chen1, Jer-Shing Huang2, and Chen-Bin Huang1,* 1Institute of Photonics Technologies, National Tsing Hua University, Hsinchu 30013, Taiwan 2Department of Chemistry, National Tsing Hua University, Hsinchu 30013, Taiwan *[email protected]
Abstract: A plasmonic two-wire transmission line (TWTL) proposed to perform ultrafast second harmonic generation (SHG). A TWTL consists of TE-like and TM-like modes. Our numerical simulations indicate that regardless of the input excitation polarization, the SHG are always TM-like. Such unique characteristic is experimentally corroborated.
1. Introduction A two-wire transmission line (TWTL) is composed of two metallic nanowires with a nanosized gap between these two nanowires, and it has insulator-metal-insulator (IMI) and metal-insulator-metal (MIM) waveguides simultaneously. With the input polarization perpendicular to the axis of TWTL, the charges on two wires are opposite, and the field is highly confined in the gap, i.e., transverse electric (TE) mode is formed. On the other hand, with the input polarization parallel to the axis of TWTL, it has a symmetric charge distribution, and field is guided through the outer surface of wires, such guided mode is transverse magnetic (TM). In the sub-wavelength scale plasmonic systems, because of the field enhancement effect, we may expect the generation of the nonlinear responses. There are many nonlinear processes, like frequency conversion, multi-wave mixing, Kerr effect, and so on. Among these nonlinear responses, we are most interested in the second-harmonic generation (SHG) because of its various applications. However, although the SHG is generated by the propagating SPs, we still wonder to know whether SHG can have the same properties like the original SP has. Thus, in this article, we first use the finite-difference time-domain (FDTD) simulations to analyze the field distribution of SHG in the transmission line, and then confirm these results by experiment. 2. Simulations For the different fundamental eigenmode (λ0 = 1560 nm), TE and TM mode has the different field distribution. TE mode propagates in the gap, while TM mode propagates outside the metal wire. However, for the SHG generated by these two different eigenmodes, there is only one mode of SHG, i.e., TM mode. Figure 1 is the field distribution of SHG.
Fig. 1. The field distribution of SHG generated by TE (left) and TM (right). 3. Experimental results Through the experiment, we not only analyze the spectrum of SHG but also record the image of SHG. Fig 2. is the EMCCD image of the SHG, and the input fundamental light is blocked.
Fig. 2. The image of SHG on EMCCD, the white double-headed arrow is the polarization of input fundamental mode. 4. References [1] P. Geisler, G. Razinskas, E. Krauss, X.-F. Wu, Christian Rewitz, Philip Tuchscherer, et al., “Multimode plasmon excitation and in situ analysis in top-down fabricated nanocircuits,” Phys. Rev. Lett. 111, 183901 (2013) [2] W.-H. Dai, F.-C. Lin, C.-B. Huang, and J.-S. Huang, “Mode conversion in high-definition plasmonic optical nanocircuits,” Nano Lett. 14, 3881 (2014) [3] S. Viarbitskaya, O. Demichel, B. Cluzel, G’erard Colas des Francs, and A. Bouhelier, “Delocalization of nonlinear optical responses in plasmonic nanoantennas,” Phys. Rev. Lett. 115, 197401 (2015)
325 P-18-02
Plasmonic Effects in X-ray Emission Induced byġġ Ultra-short Laser Pulses in Gold Colloidal Solutions
Koji Hatanaka,1* Frances Camille P. Masim,1 Wei-Hung Hsu,1 Matteo Porta,2 Tetsu Yonezawa,2 Armandas Baǐcytis,3 and Saulius Juodkazis3,4 1 Research Center for Applied Sciences, Academia Sinica 128 Academia Road, Section 2, Nangang, Taipei 11529, Taiwan 2 Department. of Materials Science, Graduate School of Engineering, Hokkaido University, Sapporo 060-8628, Japan 3 Faculty of Science, Engineering and Technology, Swinburne University of Technology, Hawthorn, VIC 3122, Australia 4 Center for Nanotechnology, King Abdulaziz University, Jeddah 21589, Saudi Arabia E-mail address:[email protected]
Abstract: Hard X-ray generation for Au nanoparticle solution was systematically investigated for different particle sizes from 10 to 100 nm in diameter with a narrow size distribution of ±2%. Scaling law of X-ray generation is close to a 6-photon process before onset of saturation for excitation by 45 fs laser pulses with central wavelength of 800 nm. This is consistent with bulk plasmon excitation at λbulk 138 nm. The longitudinal E-field component due to nanoparticle focusing is responsible for the excitation of the longitudinal bulk plasmon. The proposed analysis also explains X-ray emission from water breakdown via an electron solvation mechanism at 6.2 eV. The most efficient X-ray emission was observed for 40±10 nm diameter nanoparticles which had the strongest UV extinction. X- ray emission was the most efficient for the pre-chirped 370 ± 20 fs pulses and there was strongest at the negative chirp.
Compact and efficient hard X-ray sources can revolutionize biological and medical fields and practical applications. Liquid targets for X-ray generation by optically induced breakdown are attractive due to possibility to chose the X-ray spectrum via choice of ion content of the microjet or droplet irradiated by high ,(intensity laser pulses at 1015 W/cm2 [1,2]. At even higher intensities approaching 1020 W/cm2 (in vacuum particle accelera- tion beams for electrons and protons up to MeV energies are demonstrated using peta-watt lasers [3]. In this presentation, it is shown that the most efficient X-ray emission was observed for Au nano- particles with 40 nm diameter under irradiation of negatively pre-chirped pulses which were approximately 8 times longer as compared with the shortest 45 fs pulses as shown in Fig.1. Chirp can be efficiently used to augment the X-ray emission by a factor of two as compared with bandwidth limited pulse duration as shown in Fig.2. Power scaling of X-ray emission implies bulk plasmon excitation in gold nanoparticles and an absorption being the driving mechanism of X-ray emission. Numerical modeling of optical extinction of nanoparticles showed scattering and absorption contributions and confirmed presence of a strong E-field component perpendicular to the surface which is required to excite longitudinal bulk plasmons.
Fig.1 X-ray intensity vs Au nanoparticle size (diameter). Fig.2 X-ray intensity vs. the second order dispersion Φ2 [fs2].
[1] K.Hatanaka, T. Miura, H. Ono, H. Fukumura, "Photon energy conversion of IR femtosecond laser pulses into X-ray pulses using electro-lyte aqueous solutions in air", Science of Superstrong Field Interactions, AIP Conference Proceedings, vol.634, K. Nakajima and M. Deguchi, Eds. (2002). [2] K. Hatanaka, H. Fukumura, X-ray Spectrometry, 41, 195 (2012). [3] M. Murakami and M. Tanaka, Appl. Phys. Lett. 102, 163101 (2013).
326 P-18-03
Cross-grating of Overlapped Printed Patterns with Twin Transparent Holograms
Hsien-Chou Chen National Taiwan Normal University Department of Graphic Arts and Communication, Taipei, R.O.C. E-mail address:[email protected]
Abstract:Cross phase included the visual pattern with grating that printed on foils and films which kind of twin grating not shield ink color also merge phase into overlapped color-light. To calibrate the measure stage, recorded data of twin layers could easily capture the multiple patterns with analysis. The operations of twin layer had interacted with (1)single black line; (2)UV-LED hologram print and paste; (3)twin layer hologram. Therefore, discussed the results on the phase label, phase position, phase shield, phase shift of twin layer cross-grating. The result could well support the the cross-grating frabrication.
Keyword: cross-grating, twin layer hologram, printed pattern
327 P-18-04
Spectral-domain Optical Coherence Tomography for Detecting Temporal Phenomena of Laser Filament in Water
Cheng-Kuang Lee1,2*, Frances Camille Masim3, and Koji Hatanaka3 1Department of Electrical Engineering, Chang Gung University, 259, Wen-Hwa 1st Road, Kwei-Shan, Tao-Yuan 33302, Taiwan; 2Graduate Institute of Medical Mechatronics, Chang Gung University, 259, Wen-Hwa 1st Road, Kwei-Shan, Tao-Yuan 33302, Taiwan; 3Research center for Applied Sciences, Academia Sinica, 128, Academia Road, Section 2, Nankang, Taipei 11529, Taiwan E-mail address: [email protected]
Abstract: We generate the laser filaments in water and incorporate the light into a Spectral- domain Optical Coherence Tomography (SD-OCT) system as the light source. The measured spectral variation during several micro-seconds reveals the optical path differences due to multi filaments or air bubble formation in water.
Laser filamentation is generation of a beam of light based on Kerr effect resulting in self-focusing with high power femtosecond laser pulses. It has been observed in many materials, such as gases, liquids, transparent solids. Due to the strong nonlinear optical effect, super continuum generation can be obtained (which is also called white light laser generation) and the spectrum can be broaden from the UV to near-infrared. [1-3] In this study, we incorporate the laser filaments generated in water as the light source into a Spectral- domain Optical Coherence Tomography (SD-OCT) system. With stationary reference and sample mirror, we analyze the temporal variation of the spectrum caused by the light source. Figure 1 shows the system setup for detecting the light from laser filament. The laser pulses are focused into the tank filled with deionized water. Then the light generated from the filament is collimated into the free-space SD-OCT system which contains a 50/50 beam splitter and stationary reference and sample arms with almost the same optical path length. The interference light is received with a home-made spectrometer. Figure 2 shows the averaged optical spectrum of the filament measured by commercialized optical spectrometer.
Fig. 1. Laser filamentation and SD-OCT system setup Fig. 2. Averaged optical spectrum of the filament
Suppose there are multiple light sources locating at different positions with electric field represented by E1, E2, … En. The following equation shows the light intensity I versus wavenumber k=2S/O:
2 )( m 2¦¦ ji cos( 'lkEEEkI ij )2 (1) m z ji 'lij represents the distance between light source i and j. Eq. (1) indicates the optical spectrum of multiple light 2 sources contains the DC term (with |E| ) and interference term (with cosine function). The 'lij also implies the frequency of cosine function in k-domain. Figure 3 shows 100 optical spectra acquired by the home-made spectroscopy. Each spectrum represents the optical properties of the laser filament induced by single laser pulse. The results show that the summation of cos(2k'lij) varies dramatically with time. This phenomenon may be interpreted by the position difference of the light sources (multi filaments) or multiple light reflections due to the bubble formation in water. Whichever it is, the SD-OCT system has capability to acquire optical path difference information.
Fig. 3. 100 temporal optical spectra of laser filament acquired by home-made spectrometer
[1] V.P. Kandidov, S.A. Shlenov, and O.G. Kosareva, Quantum Electronics 39(3), 205-228 (2009). [2] S. Minardi, A. Gopal, A. Couairon, G. Tamoašuskas, R. Piskarskas, A. Dubietis, and P.D. Trapani, Opt. Lett. 34(19), 3020-3022 (2009). [3] W. Liu, O. Kosareva, I.S. Golubtsov, A. Iwasaki, A. Becker, V.P. Kandidov, and S.L. Chin, Appl. Phys. B 76, 215-229 (2003).
328 AUTHOR INDEX
Author Page Author Page
A 142 Abbas, Mohammed Nadhim 278 Chang, Chieh-Chun 312 Aeschlimann, Martin 31 Chang, Chien-Wen 144 Ahmed, Gazi A 301 Chang, Chih-Wei 66 Ahmed, Numair 255 Chang, Chin-Yu 262 Aleksandrov, I.A. 319 Chang, Hung-chun 318 Alokaily, Alaa 255 Chang, Jing-Ru 85 Anstotz, F 208 Chang, Shih-Hui Gilbert 317 Aumiller, Max 155 Chang, Shu-Wei 171 Awasthi, Saurabh 261 Chang, Shu-Yu 312 B Chang, Wen-Hao 302 Baĭcytis, Armandas 326 Chang, Yia-Chung 86 Baldassarre, Leonetta 129 195 Banerjee, Partha P. 97 278 Bansal, A. 296 299 Bekenstein, Rivka 191 307 Bernasconi, G.D. 77 Chang, Yun-Chorng 206 Betzig, Eric 11 250 Bhattacharya, Dipanjan 225 251 Biagioni, Paolo 129 253 Boltasseva, Alexandra 25 290 Boruah, Ratan 301 315 Brida, Daniele 129 Chao, Hsueh-Yu 269 Butet, J. 77 Chaudhary, Raghvendra P 293 Butet, Jérémy 60 Chaudhary, Raghvendra Pratap 261 C Chen, Alexander Ewen 321 Cencillo-Abad, Pablo 55 Chen, B. C. 291 Chan, C. T. 90 Chen, Bao-Qin 267 202 Chen, Bi-Chang 179 115 Chen, Cheng-Wen 278 Chan, Ching-Hsiang 299 Chen, Chi 228 300 Chen, Chih Kai 303 Chan, Hsun-Chi 236 Chen, Ching-Fu 232 Chang, C. 193 241 Chang, Cheng-Wei 210 246 Chang, Chia Min 231 Chen, Chun-Wei 224 Chang, Chia-Chun 162 Chen, Chun-Yu 280 Chang, Chiao-Yun 144 Chen, Chyong-Hua 224 Chang, Chia-Yuan 114 273
329 AUTHOR INDEX
Author Page Author Page
Chen, Fang-Chung 186 241 Chen, Hao Ming 303 248 Chen, His-Hsun 225 Chen, Xiao-Dong 153 Chen, Hong Wen 170 Chen, Ya-Bin 266 Chen, Hou-Ren 224 Chen, Yang-Fang 250 273 264 Chen, Hsiang-Peng 318 290 Chen, Hsien-Chou 327 Chen, Yen Chang 315 Chen, Hsi-Hsun 67 Chen, Yen-Chun 279 Chen, Hsin-Wen 325 Chen, Yi-An 85 Chen, Huai-Yi 277 Chen, Yi-Chong 205 Chen, Jhih-Yuan 243 Chen, Yi-Chun 249 Chen, Ji 200 Chen, Yi-Hao 248 Chen, Jiangjun 159 Chen, Yi-Huan 144 Chen, Jia-Wern 238 Chen, Yu Lim 303 241 Chen, Yu-Bin 187 Chen, Jyun-Hao 154 Chen, Yunju 218 Chen, Kuan-Ren 321 Chen, Yun-Ju 270 Chen, Kuo-Ju 171 Chen, Yun-Ru 280 313 Cheng, Bo Han 170 Chen, Kuo-Ping 79 241 178 Cheng, H. H. 193 Chen, Meng-Chi 73 Cheng, Ji-Yen 277 Chen, Mu Ku 231 Cheng, Pi-Ju 312 Chen, Peilin 228 Cheng, Szu-Cheng 320 Chen, Shao-Chieh 282 Cheng, Yuh-Jen 262 Chen, Shean-Jen 114 294 142 Chetia, Lakhi 301 Chen, Shiuan-Yeh 154 Cheung, Tai-Lok 78 Chen, Szu-yuan 292 Chiang, Hai Pang 238 Chen, Ting-Wei 320 244 Chen, Ting-Yu 232 245 233 Chiang, I Da 303 241 Chiang, Wei-Hsiang 85 246 Chien, Ching-Hang 86 Chen, Tzu-Yu 91 195 Chen, Wei Ting 232 299 237 Chien, Ju-Hsuan 68 238 Chien, Yi-Hsin 206
330 AUTHOR INDEX
Author Page Author Page
Chiu, Chun-Wei 279 Duan, Yubo 217 Chiu, Po-Kay 298 Dyachenko, P. N. 175 Choi, Hoi Wai 286 E Chou, Bo-Tsun 107 Ebihara, Yuusuke 156 143 Eich, M. 175 Chou, Chia-Fu 280 Endo, Maya 105 Chou, He-Chun 228 271 Chou, Hsiang-Yu 278 F Chou, Yu-Hsun 107 Fan, Shih-Kang 98 143 Fang, Chang-Wen 308 186 Fang, Meng-Han 244 Chu, Cheng Hung 231 Fang, Shenying 242 247 Feng, David Jui-Yang 304 Chu, Chia-Wei 217 Feng, Ya-Lan 249 307 Ferreira, Placid M. 255 Chu, Jen-Yu 62 Fischer, Marco P. 129 Chu, Shi-Wei 66 Frank, Bettina 31 Chuang, Pei-Yu 85 Frigerio, Jacopo 129 Chuang, Ta-Wei 252 Fritzsche, Wolfgang 167 Chuang, Ying-Hung 292 Fu, Hui-Chun 288 Chung, Yi-Cheng 107 310 Chusnutidinow, S. 222 Fu, Liwei 31 Ciou, Yu-Tang 279 Fu, Wai Yuen 286 Claveau, R 208 Fukuta, Masahiro 141 Cortés, Emiliano 106 G Csaki, Andrea 167 Gallacher, Kevin 129 D Gao, L. 311 Dan, Yaping 285 Gao, Lei 234 Das, Anirban 287 GAO, WEN SHENG 202 Dathe, Andre 167 Garwe, Frank 167 David, Jonathan Bar 59 Gierałtowska, Sylwia 220 Deng, Zi-Lan 266 Giessen, Harald 31 Dickson, W. 41 Giliberti, Valeria 129 Djurišić, Aleksandra B. 33 Godlewski, Marek 220 Dong, Chen Yuan 229 Gogoi, Ankur 301 Dong, Jian-Wen 72 Gong, Qihuang 159 153 Grajower, Meir 59 266 Griauslys, Adomas 155 Dong, Qi 33 Gu, Xijia 194
331 AUTHOR INDEX
Author Page Author Page
Guan, Chunying 242 186 Gunawan, Hariyanto 270 Hong, Minghui 125 Guo, Guang-Yu 235 Hovhannisyan, Vladimir 229 236 Hsiao, Yu-Hao 171 Guziewicz, E. 222 313 H Hsieh, Chao-Yu 323 Haibo, Li 289 Hsieh, Tsung-Han 316 Haisch, Christoph 155 Hsieh, Wen Ting 303 Halas, N. J. 15 Hsieh, Wen-Feng 224 Haldar, Arpita 309 273 Han, Chunrui 90 320 Han, Gang Hee 131 Hsu, Hsin-Feng 273 Han, Hau-Vei 302 Hsu, Hsu-Cheng 306 Han, Pin 316 Hsu, Hsun-Ching 316 Haraguchi, Masanobu 199 Hsu, Jin-Chen 263 254 312 Hatanaka, Koji 84 Hsu, Kai-Chieh 245 297 Hsu, Lung-Hsing 294 326 Hsu, Sheng-Ming 306 328 Hsu, Wei-Hung 297 Haus, Joseph W 3 326 97 Hsu, Wei-Lun 241 Hawal, Suyog R 293 Hu, Chen-Yang 267 261 Hu, Chia-Hua 252 He, Jr-Hau 185 Hu, Xiaoyong 159 288 Hu, Yvonne Yuling 114 310 142 He, Xiaolong 283 Huang, Chen-Bin 150 He, Xin-Tao 72 230 Heringdorf, Frank Meyer zu 31 251 Ho, C. Y. 291 323 Ho, Chi-Chun 187 325 Ho, Ching-Hwa 300 Huang, Chen-Hsien 268 Ho, H.P. 148 Huang, Der-Ray 85 Ho, Wen-Jeng 252 Huang, Hsiang Lin 238 305 Huang, Hung Ji 303 Ho, You Zhe 231 Huang, Jer-Shing 61 Hong, Jian-Shiung 321 73 Hong, Kuo-Bin 107 91
332 AUTHOR INDEX
Author Page Author Page
216 Jahn, Uwe 219 243 Jahr, Norbert 167 257 Jain, Rohit 261 259 Jaiswal, Arun 293 268 Janczarekm, Marcin 105 325 Jatschka, Jacqueline 167 Huang, Jian-An 286 Ji, Na 19 Huang, Jing-Kai 302 Jialong, Zhao 289 Huang, Jiong-Fu 186 Jiang, Ruei Han 62 Huang, Kun 125 Jiang, S. C. 183 Huang, Li-Ching 154 Jiang, Zen-Jia 306 Huang, S. H. 193 Jivraj, Jamil 194 Huang, Shih-Wei 278 Juodkazis, Saulius 105 Huang, Song-Bin 287 326 Huang, Xiaosheng 265 K Huang, Y. 311 Kahl, Philip 31 Huang, Yao-Wei 232 Kajikawa, Kotaro 156 238 282 241 284 248 Kamada, Shun 199 Huang, Yize 194 254 Huang, You-Xin 61 KANETA, Takashi 80 91 Kang, Byungsoo 255 Huang, Yu-Hsiang 244 Kao, Tsung Sheng 186 245 302 Huang, Zi-Huan 257 Karnik, Tushar 261 Huanga, Ming-Xue 268 Karvounis, Artemios 55 Hung, Hao-Ting 314 Kawata, Satoshi 37 Hung, Wei-Chun 278 Kawata, Yoshimasa 141 Hung, Wei-Hsuan 258 Keum, Hohyun 255 Hung, Yu-Ju 163 Kilbane, Deirdre 31 I Kim, Boram 113 Ikegami, Shiho 80 Kim, Dong-Ho 149 Inami, Wataru 141 Kim, Jeongyong 131 Isella, Giovanni 129 Kim, Kihong 240 Ishikawa, Atsushi 89 Kim, Minsu 131 J Kim, Seok 255 Jacob, Z. 175 Kim, Seulong 240 Jagadish, Chennupati 23 Klimov, Vasily 83
333 AUTHOR INDEX
Author Page Author Page
Kliuiev, Pavlo 167 235 Klosek, Kamil 219 Lang, S. 175 Kong, S.K. 148 Law, Wing-Cheung 78 Kotov, N. A. 103 Le, Thu H. H. 276 Kowalska, Ewa 105 Lee, Cheng-Kuang 328 271 Lee, Chia-Hua 298 272 Lee, Chih Jie 217 Kowalski, Bogdan J. 219 Lee, Eung Jang 113 220 Lee, Jyh-Wei 298 Kozanecki, A. 222 Lee, Keng-Yen 312 Krasavin, A. V. 41 Lee, Kevin C. J. 144 Krekeler, T. 175 Lee, Kuang-Li 162 Ku, Chen-Ta 251 Lee, Kuang-Li 275 Ku, Yun-Cheng 304 Lee, Seungwoo 255 Kuipers, L. (Kobus) 95 Lee, Tsun-Hsiun 163 Kung, Te-Jen 315 Lee, Wen-Chieh 308 Kuo, Chien-Ting 294 Lee, Yi-Yu 252 Kuo, Hao-Chung 171 Lee, Yongjun 131 294 Lee, Young Hee 131 302 Leong-Hoï, A 208 313 Lesser-Rojas, Leonardo 280 Kuo, Heng-Wei 312 Leung, Ho Ming 90 Kuo, Li Chung 303 Leung, P. T. 245 Kuo, Mao-Kuen 269 Levy, Uriel 59 304 Li, Chia-Jui 258 314 Li, H. 193 Kushida, Soh 243 Li, Han 97 Kwok, H.C. 148 Li, Hongquan 211 Kwon, Jung-Dae 149 Li, Jensen 201 L Li, Lain-Jong 144 Lai, Chao-Sung 287 302 212 Li, Lin 200 Lai, Dong-Yan 298 Li, Pin-Yi 66 Lai, Sin-An 312 Li, Tao 200 Lai, Yi-Chieh 204 Li, Wei-Shuo 224 Lai, Yung-Yu 294 Li, Yuxiang 242 Lan, Pei-Xuan 249 Li, Zhi-Yuan 267 Lan, Yung-Chiang 170 Liao, Chun Yen 237 204 241
334 AUTHOR INDEX
Author Page Author Page
Liao, Shih-Chieh 298 143 Liao, Shu-Wei 171 263 313 298 Liao, Wei-Chun 171 304 313 312 Liaw, Jiunn-Woei 218 Lin, Wei-Hsin 68 244 Lin, Wu-Chun 269 269 Lin, Yeh 249 270 Lin, Yen-Heng 287 314 Lin, Yen-Ju 304 Lin, Chen Yen 68 Lin, Yu-Ping 218 Lin, Chieh-Jen 244 Lin, Zhan-Hong 259 245 Linb, Fan-Cheng 268 Lin, Chien-Chung 107 Liu, Ai Qun 248 143 53 294 Liu, Bei 84 Lin, Chu-Hsuan 279 Liu, Chi-Ching 206 Lin, Chun-Chou 249 253 Lin, Chung-Kai 249 290 Lin, Chung-Ying 230 Liu, Fangzhou 33 Lin, Chun-Ho 288 Liu, Hao-Li 297 Lin, Chun-Yu 142 Liu, Hong 242 Lin, Fan-Cheng 91 Liu, Hsuan-Hao 318 216 Liu, Hui 115 243 191 257 201 259 Liu, Kou-Chen 84 Lin, Hsiang-Ting 144 Liu, Na 123 Lin, Hsiang-Yu 144 Liu, Ru Shi 303 Lin, Jian-Cheng 305 Liu, Tai-Chun 228 Lin, Jiunn-Yuan 292 Liu, Xin 78 Lin, Kai-Hsiang 306 Liu, Y. -C. 245 Lin, Kuo-Feng 224 Liu, Yun-Ju 66 Lin, Ming-Yi 307 Liu, Zhi-Yen 154 Lin, Sheng-Di 107 Liwei Liu 169 143 Long, Jing 211 Lin, Tien-Hsin 154 Loo, Jacky F.C. 148 Lin, Tsung-Hsien 163 Lu, Ang-Yu 302 Lin, Tzy-Rong 107 Lu, Chie-Hsun 292
335 AUTHOR INDEX
Author Page Author Page
Lu, Li-Syuan 302 N Lu, Tien-Chang 107 Naiman, Alex 59 143 Narimanov, E. E. 103 186 Nasir, M. E. 41 Lu, Xun 213 Neira, A. 41 Lu, Ya Yan 213 Ng, Annie 33 Luan, Feng 265 Ngo, Buu Trong Huynh 86 Luo, Yuan 67 195 68 Noginov, M. A. 103 217 Noriki, Takahiro 156 225 O 226 Ohtani, Bunsho 105 Lv, Wenjin 242 271 M 272 Ma, J. 103 Okamoto, Toshihiro 199 Ma, Shaojie 74 254 MacDonald, Kevin F. 55 Okuda, Koji 199 Maier, Stefan A. 106 Olesiak-Banska, J. 296 Marino, G. 41 Olesiak-Banska, Joanna 295 Markowska-Szczupak, Agata 105 Olivier, N. 41 Martin, O.J.F. 77 Ortolani, Michele 129 Martin, Olivier J. F. 60 Ota, Ryoichi 156 92 Ou, Jun-Yu 55 Masim, Frances Camille 328 P Masim, Frances Camille P. 84 Pan, Ming-Yang 162 297 281 326 Pandey, Abhishek 260 Matczyszyn, K. 296 Pang, Genny A. 155 Maurya, Santosh K. 260 Park, Hyun-Sung 255 Maurya, Santosh Kumar 261 Park, Seki 131 Mazumder, Nirmal 301 Park, Seung-Han 113 Mazurski, Noa 59 Park, Sung-Gyu 149 Mehmood, M. Q. 111 Paul, Douglas J. 129 Meng, Sun 289 Pellegrini, Giovanni 129 Mesli, Abdelmadjid 285 Pendam, NagaRaju 324 Min, Bumki 255 Peng, Chien-Chung 278 Molesky, S. 175 Peng, Chien-Jung 258 Montgomery, P 208 Peng, R. W. 183 Mukhtar, H 208 Peruh, S. 41
336 AUTHOR INDEX
Author Page Author Page
Perumal, Packiyaraj 264 Saxena, Sumit 260 Peters, V. N. 103 261 Petrov, A. Yu. 175 293 Pieniążek, Agnieszka 219 Schifano, R. 222 220 Schneider, Thomas 167 Plum, Eric 55 See, Kel-Meng 61 Podbiel, Daniel 31 91 Porta, Matteo 326 216 Prasad, Paras N 7 Segev, Mordechai 191 Przezdziecka, E. 222 Sekkat, Zouheir 161 Purwidyantria, Agnes 212 Shalaev, Vladimir M. 25 Q Shen, Kun-Ching 262 Qayyum , Hamza 292 Shen, Qian 33 Qin, Fei 125 Sheng, Chong 191 Qiu, Cheng-wei 111 Shengtao, Mei 111 125 Shi, Jinhui 242 Qiu, Feng 137 Shi, Yumeng 302 R Shih, Ching-Kuei 279 Ramjist, Joel 194 Shih, Cong-Yuan 312 Rao, Nanxi 78 Shih, Fu-Yuan 187 Reddy, M.Srinivas 309 Shih, Jheng-Hong 107 Ren, Zhiwei 33 263 Reszka, A. 222 312 Reszka, Anna 219 Shih, Min-Hsiung 144 220 171 Ristok, Simon 31 262 Ritter, M. 175 264 Roberts, Ann 71 278 Rogers, John A. 255 313 Rosa, Lorenzo 105 Shimojo, Masayuki 156 Rout, Dipak 256 Shiu, Ruei-Cheng 235 Rühm, Adrian 155 Shukla, Shobha 260 S 261 Sakat, Emilie 129 293 Samarelli, Antonio 129 Snigurenko, D. 222 Samoc, M. 296 Sobanska, Marta 219 Samoc, Marek 295 Sobczak, Kamil 219 Samuel, I.D.W. 296 Spektor, Grisha 31 Sartorello, G. 41 Stachowicz, M. 222
337 AUTHOR INDEX
Author Page Author Page
Stern, Liron 59 246 Störmer, M. 175 247 Stranik, Ondrej 167 248 Su, Xue Mei 322 303 Subiyanto, Iyan 84 Tsai, Kai-Hong 244 Sue, Ruei-Siang 305 245 Sun, Chia-Yi 317 Tsai, Meng-Lin 288 Sun, G. 193 310 Sun, Greg 237 Tsai, Shiao-Wen 218 238 270 241 Tsai, Wei-Yi 232 248 233 Sun, Shulin 248 237 Surya, Charles 33 246 T Tsai, Y. H. 291 Tai, Yi-Hsin 274 Tsao, Yang 66 Takahara, Junichi 135 Tseng, Min Lun 303 TAKEYASU, Nobuyuki 80 Tseng, Ming Lun 231 Takuo, Tanaka 276 233 Tam, Wing Yim 90 247 TAM, WING YIM 202 Tu, Wei-Chen 308 TANAKA, Takuo 80 Tumkur, T. U. 103 Tanaka, Takuo 89 Tung, Yi-Chung 278 239 U Tanyi, E. K. 103 Uen, Wu-Yih 308 Thuman, H. 103 Ueno, Kosei 49 Tien, Li-Chia 300 Ummer, K.V 214 Togawa, Ryotaro 284 Un, Ieng Wai 207 Török, Peter 237 V Tsai, Chih-Ya 224 Valente, João 55 Tsai, Din Ping 53 Vardhani, C.P. 324 170 Verma, Prabhat 47 217 Vijaya, R. 214 231 256 232 309 233 Vu, Katrin 280 237 W 238 Wachnicki, Łukasz 220 241 Wang, Chang-Han 206
338 AUTHOR INDEX
Author Page Author Page
250 Wu, Pei Ru 237 253 Wu, Pin Chieh 238 Wang, Chih-Ming 99 241 246 Wu, S.Y. 148 248 Wu, Shang-Hsuan 299 Wang, F. 65 307 Wang, Hsiang-Chu 247 Wu, Wen-Fa 298 Wang, Kunlei 272 Wu, Yen-Mo 107 Wang, Lihong V. 119 Wu, Yuh-Renn 315 Wang, Mu 183 Wu, Zheng-Yu 163 Wang, Po-Hao 217 Wurtz, G. A. 41 226 Xiangdong, Meng 289 Wang, Qiang 115 X Wang, Shing-Hoa 298 Xiao, Meng 115 Wang, Tao 322 202 Wang, Wei-Lien 252 Xiao, Shiyi 201 Wang, Yalin 283 Xiaohui, Qu 289 Wang, Yi-Chen 154 Xiong, X. 183 Wang, Yuan 153 Y Waszkielewicz, M. 296 Yamamoto, Yohei 243 Waszkielewicz, Magdalena 295 Yan, C. 77 Wei, Kung-Hwa 144 Yan, Chen 92 Wei, Pei-Kuen 162 Yang, Hong 159 274 Yang, Jhen-Hong 79 275 Yang, Jie 283 277 Yang, K.-Y. 77 281 Yang, Kuang-Yu 60 Wei, Zhishun 105 92 271 248 Wen, M. Y. 291 Yang, Tian 211 Weng, Su-Han 305 283 Wiederrecht, Gary P. 43 Yang, X. D. 194 Wirth, Janina 167 Yang, Ya-Tang 205 Witkowski, Bartłomiej S. 220 Yang, Yi-Chun 278 Wong, Man Kwong 33 Yang, Z. H. 53 Wong, Ronnie 194 Yang, Zih-Ying 178 Wu, Hui Jun 233 Yeh, Chien-Wu 305 Wu, Jyun-De 250 Yen, Chen-Chung 290 Wu, Min-Hsien 287 Yen, Ta Jen 207
339 AUTHOR INDEX
Author Page Author Page
62 Zhang, Mingqian 227 210 Zhang, Xiang 17 Yen, Yin-Ray 163 153 Yi, Hui 211 Zhao, Xingyan 285 Yokota, Yukie 239 Zhaoliang, Yu 289 276 Zheludev, Nikolay I. 29 Yokoyama, Shiyoshi 137 55 Yonezawa, Tetsu 326 Zhi, Chen 225 Yong, Ken-Tye 78 Zhong, Fan 201 147 201 265 Zhou, Jiaqi 194 Yoo, Seongwoo 265 Zhou, Lei 74 You, Meng-Lin 275 177 Yu, Cheng-Li 171 248 Yu, Hsiang-Ming 278 Zhou, Xin 283 Yu, J. W. 291 Zhou, Zhehai 223 Yu, Shang-Yang 270 Zhu, Hanyu 153 218 Zhu, Lianqing 223 Yu, Wenjing 234 Zhu, S. N. 200 Yue, Hu 289 Zhu, Shining 115 Yun, Seok Joon 131 191 Z 201 Zayats, A. V. 41 Zhu, Zheng 242 Zeimer, Ute 219 Zhuo, Zhong Chang 322 Zektzer, Roy 59 Zhuravlev, K.S. 319 Zhai, Xiaomin 217 Zopf, David 167 225 Zytkiewicz, Zbigniew R. 219 Zhang, Baile 217
340
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Date & Time: 18:30‐20:30 Tuesday, March 22 Place: B1, Chang Yung‐Fa Foundation (11 Zhongshan S. Rd., Zhongzheng Dist., Taipei 100, Taiwan) Fee: Included in conference fee. Registered accompanying person are invited to the banquet. Traffic: The shuttle bus will be at the 1st floor of the conference building at 17:30 PM
The Chang Yung‐Fa Foundation International Convention Center is located on Zhongshan South Road, an easily accessible thoroughfare. The building faces the Ketagalan Boulevard and is close to the National Taiwan University Hospital and Liberty Square (Chiang Kai‐shek Memorial Hall). It is a 5 min walk from MRT National Taiwan University Hospital Station and a 5 min drive from Taipei Main Station. (Underground parking available for compact cars) National Highway No. 1 ‐‐> Jianguo Expressway ‐‐> Jing Fu Men on Renai Rd. Zhongzheng Bridge ‐‐> Chongqing S. Rd. ‐‐> Presidential Office Building ‐‐> Ketagalan Blvd. ‐‐> Xinyi Rd. Zhongxiao Bridge ‐‐> turn right onto Zhongxiao W. Rd. ‐‐> Zhongshan S. Rd.
Taipei Bridge ‐‐> Minquan W. Rd. ‐‐> Sec. 2, Zhongshan N. Rd. ‐‐> Zhongshan S. Rd.
Take line 2 to National Taiwan University Hospital Station and walk one block south to Sec 1, Renai Road (also called 3rd Blvd). This walk takes approximately five minutes. Take line 2, or 3 to CKS Memorial Hall Station, then across CKS Memorial Hall to Sec 1, Xinyi Road (also called 2nd Blvd). This walk takes approximately fifteen minutes.
To Renai‐Zhongshan Intersection: Bus Nos. 214, 245, 261, 263, 270, 37, 621, 630, 651 To Renai‐Linsen Intersection: Bus Nos. 214, 214 (Express), 245, 249, 261, 263, 270, 37, 621, 630, 651 To Xinyi‐Linsen Intersection: Bus Nos. 0‐East, 20, 204, 22, 237, 38, 670 (Xinyi Trial Line) To Jing Fu Men: Bus Nos. 15 (Sectional Route), 15 (Wanmei Line), 208 (Expressway
Line),208 (Keelung River 2nd Term Public Housing Line)
Taoyuan Airport Taiwan : http://www.taoyuan‐airport.com/english/Index/ Taipei Songshan Airport : http://www.tsa.gov.tw/tsa/en/home.aspx Taiwan High Speed Rail : http://www5.thsrc.com.tw/en/ Taiwan Railways Administration : http://www.railway.gov.tw/en/ Metro Taipei : http://english.metro.taipei/
Taipei Bus Information and Transit System : http://www.5284.com.tw/Dybus.aspx?Lang=En