GSELOP2021 Global Summit and Expo on Laser, Optics and Photonics August 23-25, 2021 Paris, France

The Scientistt Bangalore, Karnataka, India Contact: +91 77 99 83 5553 Email: [email protected] GSELOP2021 Global Summit and Expo on Laser, Optics and Photonics August 23-25, 2021 | Paris, France FOREWORD Dear Colleagues,

We are pleased to announce that the Global Summit and Expo on Laser, Optics and Photonics(GSELOP2021) will be held during August 23-25, 2021 in Paris, France is a premiere and one of the highest level international academic conferences in the field of laser, optics and photonics.

The GSELOP2021 will present the most recent advances in technology developments and business opportunities in laser, optics and photonics commercialization. Highly cited researchers from renowned universities across the globe and industry leaders will share their research and vision, while selected talks from industrial exhibitors will present commercial showcases in all current market fields of optics and photonics.

This conference offers an excellent forum for the state of art presentations by invited speakers, leading specialists in the field of laser, optics and photonics. Most recent developments, progress and achievements realized in the fields covered by the conference will be presented in plenary, keynote presentations and short oral contributions as well as in poster sessions.

As you enjoy the intellectual interaction with peers and leaders in the field, we encourage you to immerse yourselves in the Paris experience with her rich cultural diversity. We are confident that your stay with us will be enriching and fascinating.

Welcome to Paris and we wish you a pleasant, fruitful and unforgettable experience!

Sincerely, Prof. Dieter Bimberg Conference Chair GSELOP2021 "Bimberg Chinese-German Center for Green Photonics" at CIOMP of CAS, Changchun. Founding Director "Center of NanoPhotonics", TU Berlin, Germany.

Page- 2 GSELOP2021 Global Summit and Expo on Laser, Optics and Photonics August 23-25, 2021 | Paris, France COMMITTEES Organising Committee

Prof. Dieter Bimberg Bimberg Chinese-German Center for Green Photonics, CAS at CIOMP, Changchun. Founding Director Center of NanoPhotonics TU Berlin, Germany Dr. John Ballato J. E. Sirrine Endowed Chair of Optical Fiber and Professor, Clemson University, USA Prof. Yuri Kivshar Nonlinear Physics Center, Australian National University, Australia Prof. Sailing He Royal Institute of Technology,Sweden Zhejiang University, China Prof. Oliver Ambacher Fraunhofer Institute for Applied Solid-State Physics, Germany Dr. Angela Dudley University of the Witwatersrand, South Africa Dr. Matthieu Lancry Université Paris Sud in Université Paris Saclay France Prof. Tie Jun Cui Southeast University, China Dr. A.Martirosyan Institute for Physical Research, NAS of Armenia, Armenia Prof. Takashige Omatsu Chiba University, Japan Prof. Xiaolong Hu Tianjin University, China Dr. Lu Zhang Zhejiang University, China Prof. Francisco M. Morales University of Cádiz, Spain Prof. Xiaosheng Fang Fudan University, China Prof. Shuqin Lou Beijing Jiaotong University, China Prof. Ci-Ling Pan National Tsing Hua University, Taiwan

Page- 3 Plenary Forum GSELOP2021 Global Summit and Expo on Laser, Optics and Photonics August 23-25, 2021 | Paris, France Dieter Bimberg "Bimberg Chinese-German Center for Green Photonics", Chinese Academy of Sciences at CIOMP and TU Berlin [email protected] and [email protected]

Green VCSEL Designs for the Next Generation of Data Com and Automotive

Abstract Several novel approaches for the design of GaAs-based VCSELs and VCSEL arrays for data com and automotive applications at 850-1310 nm are reported. They are based on optimizing the photon lifetime and oxidizing the apertures from previously etched holes. Increase of output power, roll-over current, cut-off frequency and reduction of series resistance are predicted. Using QDs as active material at longer wavelengths beyond 1150 nm is suggested.

Keywords surface emitting lasers, energy efficiency, 100+ Gb data com, LIDAR

References [1] G. Larisch, R. Rosales, and D. Bimberg, “Energy-efficient VCSELs for 200+ Gb/s optical interconnects”, IEEE J. Select. Topics in Quantum Electronics, 25, 1701105 (2019) [2] P. Moser et al., “ Impact of the Oxide-Aperture Diameter on the Energy Efficiency, Bandwidth, and Temperature Stability of 980-nm VCSELs”, J. of Lightw. Tech., 33, 825 (2015) [3] G. Larisch, P. Moser, J. A. Lott, and D. Bimberg, "Large Bandwidth, Small Current Density, and Temperature Stable 980-nm VCSELs," IEEE Journal of Quantum Electronics, 53, no. 6, pp. 1-8, 2017 [4] G. Larisch, S. Tian, D. Bimberg, “Optimization of VCSEL photon lifetime for minimum energy consumption at varying bit rates”, Optics Express 28, 18331 (2020) [5] D. Bimberg et al., “Advanced Energy-Efficient VCSEL Designs for Large Data Rates”, OFC Panel on ”Advanced Laser Technologies in Post-100 Gbaud Era”, San Francisco June 2021 [6] G. Larisch, Tian Sicong and D. Bimberg: "Multi-Aperture VCSEL and holes with metal as thermal sink", EP 20 192 355.4 + US 17/170,834 [7] G. Larisch, Tian Sicong and D. Bimberg: "Multi-Section VCSEL", EP 20 210 737.1 + US 17/170,709 [8] D. Bimberg, N. N. Ledentsov, M. Grundmann et al., „Edge and surface mitting InAs quantum dot lasers”, Solid State Electronics 42, 1433 (1998) [9] D. Bimberg, N. N. Ledentsov, J. A. Lott, “Quantum dot vertical-surface-emitting lasers”, MRS Bulletin 27, 531 (2002)

Page- 5 GSELOP2021 Global Summit and Expo on Laser, Optics and Photonics August 23-25, 2021 | Paris, France O. Ambacher Fraunhofer Institute for Applied Solid State Physics (IAF), Tullastrasse 72, 79108 Freiburg, Germany; Email: [email protected]

Diamond Spin-Photon-Based Quantum Computer Abstract Spins in solids, and among those from dopants in diamond, are close to ideal quantum bits with record relaxation and coherence time as well as excellent coherent control. Out-standing 1- and 2-qubit gate fidelities have been reported [1-3]. The physical implementation of thequbit architecture is based on dopants in diamond forming colour centres such as the nitrogen vacancy (NV) centre. This colour centre possess a paramagnetic ground state, that hosts electronic spin-systems. Their individual spin states can be initialized and readout optically with high fidelity. This central electron spin of the individual colour centres in diamond exhibit interactions with surrounding 13C nuclear spins, which can be controlled by microwave fields and thus allows it to function both as a readout and a quantum control unit of the nuclei. The 13C nuclear spins serve as physical qubits, whose different hyperfine interactions with the electron spins make them spectrally addressable. A central challenge that currently limits the scalability of the spin system is that the 1- and 2-qubit gates require frequency selectivity and, with an increasing number of nuclear spins, can no longer be implemented with a quality that is sufficient for deep algorithms. This is why we restrict the size of the number of nuclear spins per register to around 8 qubits. The key element to entangle local registers to upscale the number of nuclear spin qubits is the distribution of entanglement between electron spin qubits via photons. The lecture gives an overview of the state of the art of nuclear spin-based qubits and quantum gates and an insight into the functionality of future diamond spin-photon-based quantum computers.

Keywords Quantum Computing, Spin Qubits, Diamond, Colour Centres

References [1] C. E. Bradley, et al., Phys. Rev.X9,031045 (2019). [2] M. J. Degen, et al., Nature Communications 12, 3470 (2021). [3] S. Pezzagna and J. Meijer, Appl. Phys. Rev.8, 011308 (2021).

Biography Oliver Ambacher received his diploma and doctor of natural sciences at the Ludwig-Maximilians and the Technical University of Munich with distinction in 1989 and 1993. In 1995 he focused the research work of his group on the processing of GaN-based electronic and optical components. In 1998/99 he was offered the Feodor Lynen grant from the Alexander von Humboldt Foundation at Cornell University. Following his habilitation in experimental physics in 2000 he was appointed professor for nanotechnology at the Technical University of Ilmenau. In 2002 he was elected director of the Institute for Solid State Electronics and two years later he was appointed director of the Center for Micro and Nanotechnologies. Since October 2007, Oliver Ambacher has been a professor at the Albert Ludwig University in Freiburg and head of the Fraunhofer Institute for Applied Solid State Physics, where he is currently involved in the development of quantum sensors and quantum computers. Page- 6 GSELOP2021 Global Summit and Expo on Laser, Optics and Photonics August 23-25, 2021 | Paris, France M. Merano Dipartimento di Fisica e Astronomia “Galileo Galilei”, Università degli Studi di Padova, via Marzolo 8, I-35131, Padova Italy. [email protected] Measurement of the Out-of-Plane Susceptibility of

Monolayer Graphene and MoS2

Abstract I report an experiment that measures, for the first timein the visible spectrum, the out-of-plane susceptibility of a single-layer two-dimensional (2D) crystal1. The sensitivity of an optical measurement to anisotropy is dependent on the path length of the light through the material, which is extremely limited for a monolayer 2D crystal. The substrate hides the contribution of the out-of-plane optical constants and experiments are only sensitive to the in-plane properties2.

In order to remove the substrate contribution, an ideal measurement should be done on a large area free-standing 2D crystal. Unfortunately, the manipulation of such a crystal represents an extraordinary challenge. We successfully embed a single-layer 2D crystal in the middle of a polydimethylsiloxane(PDMS) prism without altering its optical response. The PDMS does not add any spurious interface,possibly hiding the optical response of the 2D crystal. This trivializes the handling of the sampleand it allows for a complete optical characterization of a monolayer.

We expect a precise measurement of the out-of-plane optical constants of 2D crystals to become of great importance in photonics and optoelectronics.

Keywords Graphene, 2D crystals, monolayer, optical properties.

References [1] Z. Xu, D. Ferraro, A. Zaltron, N. Galvanetto, A. Martucci, L. Sun, P. Yang, Y. Zhang, Y. Wang, Z. Liu, J. D. Elliott, M. Marsili, L. Dell’Anna, P. Umari and M. Merano (2021), submitted to Nature Photonics, available at Research Square, DOI:10.21203/rs.3.rs-266618/v1 [2] F. J. Nelson, V. K. Kamineni, T. Zhang, E. S. Comfort, J. U. Lee, and A. C. Diebold. Appl. Phys. Lett. 97, 253110 (2010).

Page- 7 GSELOP2021 Global Summit and Expo on Laser, Optics and Photonics August 23-25, 2021 | Paris, France

Biography Michele Merano received the Ph.D degree in Physics at EPFL in Lausanne (Switzerland) where he worked in the group of Prof Benoît Deveaud. Then he did two post docs one at the Laboratoired’OptiqueAppliquée (Palaiseau, France) with Prof. Gérard Mourou and one at the Quantum Optics and Quantum Information group (Leiden, The Netherlands) with Prof. Han Woerdman. From 2011 he is professor of optics and condensed matter physics at University of Padua (Italy). His major research interests include light matter interaction, beam optics and optical manipulation. He has made important contributions to optics and materials science including the observation of the Goos-Hänchen effect in metallic reflection, the observation of angular deviations in specular reflection of a light beam, and the discovery of the role of the radiation-reaction force in the optical response of 2D materials.

Page- 8 GSELOP2021 Global Summit and Expo on Laser, Optics and Photonics August 23-25, 2021 | Paris, France J. Wang1,2,* J. Wang1,2,*, B.G.Wang2, Y.K.Ding2, Q.C. Dan2, S.Y. Tan1,2, L. Zhou1,2, H. Liu1,2, H. Yu1,2, X.S. Liao1,2, S.H. Zhou2 1Suzhou Everbright Photonics Co. Ltd., Suzhou, Jiangsu,,PR. China 2Sichuan University, Chengdu, Sichuan,P.R. China *Email: [email protected]

The Development of High Power Diode Lasers- Performance and Manufacturing

Abstract High power semiconductor lasers are widely used as the pump sources for fiber lasers and solid state lasers, or the light sources of direct diode laser systems. To meet the emerging development of these applications, diode lasers are moving towards higher power, higher brightness, higher efficiency and higher reliability, as well as higher volume manufacturing.

Through studying epitaxial processes of compound materials using 6” wafer systems, optimizing laser waveguide structures, developing facet passivation techniques, utilizing beam combining techniques, our semiconductor laser devices have been improved in terms of power, efficiency, brightness, as well as spectral properties. In this talk, we will present our recent experimental results, including more than 14W output from a high brightness single emitter chip with 50 mm wide emitting aperture, more than 1000W QCW output power and greater than 75% efficiency at room temperature from a 1 cm wide laser barwith a double-diodestructure connected through a tunneling junction. We will also report the development of kilo-watt/20 kilo-watt fiber coupled semiconductor laser systems for metal cutting, welding and 3D-printing, hundred-watt chips for LIDAR, high power VCSEL arrays for 3D sensing.

Keywords High power diode laser, high efficiency, high brightness

Biography Dr Jun Wang is the CTO of Suzhou Everbright Photonics Co. and a professor of Sichun University. He received a Ph.D. degree in Engineering Physics from McMaster University, Canada in 1997. Since 1992, he has been studying or working on compound semiconductor materials and diode laser devices in several companies and institutions, including SLI, Spectra-Physics, Lasertel ，nLight and Everbright Photonics. He has led or participated in a number of research and development programs in the area of high power semiconductor lasers. He has more than 30 publications reporting record results on efficiency, output power and reliability of diode lasers.

Page- 9 Invited Forum GSELOP2021 Global Summit and Expo on Laser, Optics and Photonics August 23-25, 2021 | Paris, France K. Krupa1,* K. Krupa1,*, T. M. Kardaś2, B. Piechal1, J. Szczepanek1, K. Nithyanandan3,4, P. TchofoDinda3, Ph. Grelu3, and Y. Stepanenko1 1Institute of Physical Chemistry Polish Academy of Sciences, ul. Kasprzaka 44/52, 01-224 Warsaw, Poland. 2Fluenece sp. z o.o., ul. Kasprzaka 44/52, 01-224 Warsaw, Poland 3Laboratoire Interdisciplinaire Carnot de Bourgogne, U.M.R. 6303 C.N.R.S., Université Bourgogne Franche-Comté, 9 Avenue Alain Savary, BP 47870, F-21078 Dijon, France 4Department of Physics, Indian Institute of Technology Hyderabad, Kandi, Telangana 502285, India *[email protected]

Recent Advances in Real-Time Dynamics of Ultrafast Fiber Lasers

Abstract Ultrafast lasers have been the subject of constant research offering a powerful platform for investigating various interesting nonlinear dynamics. Indeed, mode-locked fiber lasers can host numerous dissipative soliton interactions, resulting from the interplay of nonlinearity, dispersion, and dissipation. Although dissipative solitons are known for many years, only recently, their single-shot characterization has been made available by developing advanced measurement techniques [1,2]. These real-time techniques have allowed us to directly observed the ultrafast features of dissipative solitons, which so far have been accessible only through numerical simulations, thus paving the way towards a deeper understanding of the complexity of fiber laser operation. This talk will overview recent advances in fiber laser dynamics showing various ultrafast nonlinear phenomena recently unveiled experimentally in ultrafast fiber lasers. We will reveal the internal motions within soliton molecules [3], soliton explosions and instabilities, and self-organization within vector incoherent dissipative solitons [4].

Moreover, we will present the pulse build-up process of harmonic mode-locking, including its establishing and stabilizing stages, as well as the moment of the switching between the consecutive orders of the harmonics [5]. Finally, we will demonstrate experimental evidence of double-Hopf bifurcation dynamics. We will discuss the possible explanation of this phenomenon by exploring the numerical approach that combines the interplay of the population inversion in the laser medium with the pulses energy [6].

Keywords ultrafast lasers, dissipative solitons, Dispersive Fourier Technique

Page- 11 GSELOP2021 Global Summit and Expo on Laser, Optics and Photonics August 23-25, 2021 | Paris, France

References [1] K. Goda and B. Jalali, Nat. Phot. 7, 102 (2013). [2] P. Ryczkowski, M. Narhi, C. Billet, J.-M. Merolla, G. Genty, and J. M. Dudley, Nat. Photonics 12, 221 (2018). [3] K. Krupa, K. Nithyanandan, U. Andral, P. Tchofo-Dinda, and P. Grelu, Phys. Rev. Lett. 118, 243901 (2017). [4] K. Krupa, K. Nithyanandan, Ph. Grelu, Optica 4, 1239 (2017). [5] B. Piechal, J. Szczepanek, T. M. Kardas, and Y. Stepanenko, IEEE Xplore 39, 574 (2021). [6] K. Krupa, T. M. Kardas, and Y. Stepanenko, SPIE Proc. 11671 (2021).

Biography Katarzyna Krupa received her PhD in ‘cotutelle’ between the University of Besançon (France) and the Warsaw University of Technology (Poland) in 2009. Her doctoral thesis was focused on development of new methods for MEMS/MOEMS reliability investigation. In 2010 she joined the XLIM Institute of the University of Limoges (France) as a post-doctoral researcher in nonlinear optics. In 2016 she moved to the Laboratoire Interdisciplinaire Carnot de Bourgogne (ICB) of the University of Bourgogne, to work on mode-locked fiber lasers. In 2018 she spent one-year at the University of Brescia (Italy) as a Marie Curie Fellow conducting research in the area of multimode fiber optics. Currently she continues her work at the Institute of Physical Chemistry Polish Academy of Sciences (IPC PAS) in Warsaw. Her research interests deal with fiber lasers and spatiotemporal nonlinear fiber optics. She is co-author of 50 scientific articles in top-ranked international journals and more than 100 publications in peer-reviewed conference proceedings.

Page- 12 GSELOP2021 Global Summit and Expo on Laser, Optics and Photonics August 23-25, 2021 | Paris, France A. Halstuch1,* A. Halstuch1,*, Seongwoo Yoo2, and Amiel A. Ishaaya1 1School of Electrical and Computer Engineering, Ben-Gurion University of the Negev, Beer-Sheva 8410501, Israel 2School of Electrical and Electronic Engineering, Centre of Optical Fiber Technology, The Photonics Institute, Nanyang Technological University, 50 Nanyang Avenue, Singapore 639798, Singapore *[email protected] Novel Methods for Fs Inscription of Fiber Bragg Gratings and their Applications Abstract Femtosecond (fs) laser material processing, micromachining and induced refractive index change in transparent materials have become important tools for processing a variety of materials in the last two decades [1]. The main advantage of using a fs laser source for processing materials is that its high peak power pulses can deliver energy into materials in an ultrafast manner, resulting in high precision and minimal collateral damage. Numerous devices and applications such as fiber Bragg gratings (FBGs), waveguides, couplers, and filters have been reported [2]. Fs inscription of FBGs has been widely explored, and grating inscriptions in different types of fibers, and with various focusing conditions have been demonstrated. Today, there are mainly two techniques for inscribing FBGs with the fs laser: First, the point-by-point [3] and the line-by-line techniques [4] in which grating planes are formed one by one. Second, the phase-mask (PM) technique where the grating is inscribed as a whole [5,6].

In this talk, novel methods for FBG inscription with fs pulses and its applications are presented. An amplified Ti:Sapphire fs laser with 35 fs pulse duration and 1 KHz repetition rate, is used employing the PM technique with a cylindrical lens as shown in Fig. 1. The effect of fs pre- and post-photo- treatment is characterized, and it is shown that the center Bragg wavelength in silica fibers can be fine-tuned and the Bragg wavelength can be red-shifted with fs pre-photo-treatment. The ability to slightly blue-shift and red-shift the Bragg wavelength with post-photo-treatment is also demonstrated. A method for inscribing phase-shifted-gratings by tuning the inscription wavelength simply by applying strain to the fiber during inscription, or moving the PM is shown as well.

Fig. 1. Femtosecond inscription setup with the PM technique. Page- 13 GSELOP2021 Global Summit and Expo on Laser, Optics and Photonics August 23-25, 2021 | Paris, France

In addition, we inscribe an FBG on an active Yb-doped large-mode-area multicore fiber for a laser application. We integrate the active fiber with the inscribed FBG into a laser configuration and pump with a 976 nm fiber diode laser. We measure a slope efficiency of ~72% and a maximum output power of 51.8W for a pump power of 82.5W. We show reflection uniformity among the cores, indicating the quality of the FBG inscription process.

Keywords Femtosecond inscription, phase-mask, fiber-Bragg-gratings, phase-shifted-gratings, optical-fibers, fiber-lasers

References [1] R. R. Gattass, E. Mazur, Nat. Photonics 2(4), 219-225 (2008). [2] G. Della Valle, R. Osellame, and P. Laporta, J. Opt. A, Pure Appl. Opt. 11, 013001 (2009). [3] A. Martinez, M. Dubov, I. Khrushchev, and I. Bennion, Electron. Lett. 40(19), 1170-1172 (2004). [4] K. Zhou, M. Dubov, C. Mou, L. Zhang, V. K. Mezentsev, and I. Bennion, IEEE Photonics Technology Letters, 22(16), 1190-1192 (2010). [5] J. Thomas, C. Voigtlaender, R. G. Becker, D. Richter, A. Tuennermann, and S. Nolte, Laser Photonics Rev. 6, 709 (2012). [6] Stephen J. Mihailov, Dan Grobnic, Christopher W. Smelser, Ping Lu, Robert B. Walker, and Huimin Ding, Opt. Mater. Express 1, 754-765 (2011).

Biography Aviran Halstuch is a postdoc researcher at Ben-Gurion University of the Negev working with Prof. Amiel Ishaaya. Aviran received his B.Sc. and B.A. in Mechanical Engineering and Physics respectively (both cum laude) from the Technion, Israel Institute of Technology. Aviran earned his M.Sc. (summa cum laude) in Electro-Optical Engineering, and his PhD in Electrical and Computer Engineering from Ben-Gurion University of the Negev. His research is focused on femtosecond inscription and laser material processing and specifically on fiber Bragg gratings inscription with the phase-mask technique. Aviran is the recipient of several awards, including the Negev scholarship for outstanding PhD students at Ben-Gurion University of the Negev, and the three-year scholarship from the Israel Ministry of Science, Technology and Space for PhD students in Applied Science.

Page- 14 GSELOP2021 Global Summit and Expo on Laser, Optics and Photonics August 23-25, 2021 | Paris, France Witold Trzeciakowski1 Witold Trzeciakowski1, Kamil Jurczyszyn2, Jacek Szymańczyk3, Yurij Ivonyak1, Zdzisław Woźniak2, Agata Mańkowska4 1Institute of High Pressure Physics, Polish Academy of Sciences, Warsaw, Poland

2Medical University of Wrocław, Wrocław, Poland

3Medical University of Warsaw, Warsaw, Poland

4Medical Aesthetics SALUS MedicalClinic, Poznań, Poland

Combining Different Laser Wavelengths for Medical Applications Abstract We used a simple method for coupling 8 laser-diode beams into an optical fiber [1] and we developed a laser source for dermatological applications, operating CW or pulsed. We could choose to obtain high emission power at a single wavelength or up to 8 different wavelengths at moderate powers. Our blue source at up to 48W CW power has been tested for the treatment of Port Wine Stains, Telangiectasia, common nevi and plantar warts [2]. These lesions have been previously treated

with green KTP lasers, yellow dye lasers, and CO2 laser but the blue laser turned out to be equally effective. For the multiple wavelength source we used violet, blue, green (InGaN/GaN) and red (InGaP) laser diodes; this has opened some interesting possibilities for studying the effect of light on the tissue. In particular, we found a synergy effect when illumining tissue with green and blue light; the temperature increase of the tissue was higher when the two colors have been applied together then when each color was applied separately (for the same power in each case) [3]. The multi- color laser was also used to study the human gingival fibroblast proliferation comparing different wavelengths and their combinations [4].Finally, the violet and red source turned out to facilitate photodynamic therapy of basal cell carcinoma [5]. The visible laser-diode source seems to be a versatile tool for medical applications, replacing more expensive sources like CO2, KTP or dye lasers. Thisresearch was funded by National Center for Research and Development in Poland (Narodowe Centrum Badań i Rozwoju) project nr PBS3/A7/18/2015

1. Y. Ivonyak, B. Piechal, M. Mrozowicz, A. Bercha, W. Trzeciakowski (2014) Coupling of multiple laser diodesinto a multi-modefiber, Review of Scientific Instruments 85, 036106 https://doi. org/10.1063/1.4868598 2. J.Szymańczyk, W. Trzeciakowski , Y.Ivonyak , P. Tuchowski, and J.Szymańczyk, Blue Laser (450 nm) in the Treatment of Port Wine Stains and Telangiectasia, Journal of ClinicalMedicine2021, 10(6), 1258; https://doi.org/10.3390/jcm10061258 3. Jurczyszyn, K.; Trzeciakowski, W.; Woźniak, Z.; Ziółkowski, P.; Trafalski, M. Assessment of Effects Page- 15 GSELOP2021 Global Summit and Expo on Laser, Optics and Photonics August 23-25, 2021 | Paris, France of Laser LightCombining Three Wavelengths (450, 520 and 640 nm) on TemperatureIncrease and Depth of TissueLesions in an Ex Vivo Study. Materials2020, 13, 5340, doi:10.3390/ma13235340. 4. B. Sterczała, K. Grzech-Leśniak, O. Michel, W. Trzeciakowski, M. Dominiak and K.Jurczyszyn,Assessment of Human Gingival Fibroblast Proliferationafter Laser Stimulation In Vitro Using Different Laser Types and Wavelengths (1064, 980, 635, 450, and 405 nm)—Preliminary Report, Journal of PersonalizedMedicine2021, 11(2), 98; https://doi.org/10.3390/jpm11020098 5. Woźniak Z, Trzeciakowski W, Chlebicka I, Ziółkowski P,PhotodynamicDiagnosis and PhotodynamicTherapy in Basal Cell Carcinoma Using NovelLaser Light Source,Photodiagnosis and PhotodynamicTherapy(2020), doi: https://doi.org/10.1016/j.pdpdt.2020.101883

Page- 16 GSELOP2021 Global Summit and Expo on Laser, Optics and Photonics August 23-25, 2021 | Paris, France O.Spitz1,* O.Spitz1,*, P.Didier1,D. A.Diaz-Thomas2, L. Cerutti2, A. N.Baranov2, and F. Grillot1,3

1LTCI, Institut Polytechnique de Paris, 19 place Marguerite Perey, 91120 Palaiseau,France 2IES, Université de Montpellier, CNRS UMR 5214, 34000 Montpellier, France 3CHTM, University of New-Mexico, 1313 Goddard SE, Albuquerque, NM 87106, USA *[email protected]

Unlocking High-Speed Dynamics and Direct- Modulation at Mid-Infrared Wavelength with Energy- Efficient Interband Cascade Lasers

Abstract The mid-infrared domain has recently attracted a renewed attention with the development of free- space communication [1] and its extension to private scheme [2]. These efforts focused on quantum cascade lasers (QCLs) but there are other semiconductor lasers of interest in this wavelength domain. Interband cascade lasers (ICLs) technology is currently less mature than QCLs but it holds many promises [3]. The electrical power consumption of ICLs is generally below 1 Watt while the optical power can reach a few dozens of mW. These sources are thus optimized for portable light optical systems. In this work we show that ICLs exhibit superior features in terms of chaos bandwidth and direct modulation for communication, as shown in the following figure. This paves the way for end-user applications other than gas spectroscopy [3].

Figure: ICL eye diagram for a 2.5 Gbits/s back-to-back transmission (left) and ICL non-linear dynamics bandwidth (right) with typical chaotic timetrace in inset

Keywords Interband cascade laser, chaos dynamics, high-speed modulation, free-space optics, private communication, mid-infrared photonics

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References [1] X. Pang et al.,physicastatussolidi (a), 218, 2000407, (2021). [2] O. Spitz et al., Nature Communications, 12, 3327, (2021). [3] J. R. Meyer et al.,“The Interband Cascade Laser,” Photonics, 7, 75, (2020).

Biography Olivier Spitz received the Ph.D. degree from Université Paris-Saclay, France, in 2019, and is now postdoctoral researcher with Télécom Paris, InstitutPolytechnique de Paris, France, working on applications of mid-infrared quantum/interband cascade lasers. His research interests include non- linear dynamics, free-space communications and neuromorphic photonics.

Page- 18 GSELOP2021 Global Summit and Expo on Laser, Optics and Photonics August 23-25, 2021 | Paris, France W. T Hill, III1,2,3 W. T Hill, III1,2,3, L. Roso4,5, R. Fedosejevs6, R. Lera5, S. Ravichandran1,2, A. Longman6, C. Z He1,2, José Antonio Pérez-Hernández4 and Jon I Apiñaniz4

1 Joint Quantum Institute, University of Maryland, College Park, MD 20742 USA. 2 Institute for Physical Science and Technology (IPST), University of Maryland, College Park, MD 20742 USA. 3 Department of Physics, University of Maryland, College Park, MD 20742 USA. 4 Centro de Láseres Pulsados (CLPU), 37185 Villamayor, Salamanca, Spain. 5 Departamento de Física Aplicada, Universidad de Salamanca, 37008 Salamanca, Spain. 6 Electrical and Computer Engineering, University of Alberta, Edomonton, Alberta T6G 2V4, Canada. *[email protected]

Precision Measurement of the Quantum Vacuum with Ultrafast, Ultra-Intense Lasers

Abstract Ultra-intense laser pulses of short duration have placed us at the threshold of a new era where novel experimental investigations of nonlinear aspects of quantum electrodynamics (QED) will be possible. Fundamental tests of QED from the photon side and its intimate coupling to the quantum vacuum are on the horizon. The very essence of the vacuum is pleached with a fundamental tenet of quantum physics – quantum fluctuation – virtual particles and antiparticles (e.g., electron-positron pairs) fluctuating into and out of existence. Quantitative measurements of virtual particles not only will challenge calculations from the 1930s, they will set strenuous limits for add-ons to the Standard Model. Photons are unique probes in that they are uncharged and their Bosonic nature allows unlimited numbers of them to be co-located within an arbitrarily-small volume, at least classically. Quantum mechanics makes a different prediction. As the intensity increases, the linear response of light propagating in a physical vacuum, as Maxwell equations demand, gives way to a nonlinear response. Post-Maxwellian theories, of which QED is one, allow virtual pairs to mediate an interaction between photons that can be viewed, to some extent, as light propagating through material. At high enough intensity the quantum vacuum will break down, inducing real pairs to emerge. The 29 2 critical intensity (Icr) for breakdown, the so-called Schwinger limit, is ~ 2 10 W/cm . Even though Icr is beyond current technology, there are fundamental features of the quantum vacuum that can be explored at substantially lower intensities [1]. In this talk we will explore some of these ideas, focusing on the new physics that can be learned, and the tools and conditions required for precision measurements.

Acknowledgments National Science Foundation Grant PHY2010392; Laserlab Europe V Grant 871124; Junta de Castilla y León Grant CLP087U16; Natural Sciences and Engineering Research Council of Canada Grant RGPIN-2019-05013).

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Keywords Quantum Vacuum, QED, Photon-Photon Scattering, Extreme Laser Intensity

References 1. W. T. Hill, III and L. Roso, J. Phys: Conf. Series 869, 012015 (2017).

Page- 20 GSELOP2021 Global Summit and Expo on Laser, Optics and Photonics August 23-25, 2021 | Paris, France Chee-Keong Tan Department of Electrical and Computer Engineering, Clarkson University New York, USA Recent Progress in Dilute-Anion III-Nitrides

Abstract The progress in the conventional III-Nitride semiconductor devices have directly resulted in the revolutions of solid state lighting technology. Despite the rapid development of InGaN-based visible light emitting diodes (LEDs), the problems including the efficiency droop exist in the devices. Tremendous efforts have been put into improving efficiency of the LED devices, but the underlying mechanisms behind the device issues are fundamentally unresolved using conventional III-Nitride materials. Consequently pursuing the suitable strategy through material and heterostructure innovations will be critical for electronics and optoelectronics device applications.

In this presentation, I discuss the development in dilute-anion III-Nitrides, an innovative III-Nitride material class, for device applications. The advantages in implementing the dilute-anion III-Nitrides semiconductor like the dilute-As GaNAs for devices including light emitters and transistors will be discussed. Specifically, in the case of light emitters, the design of dilute-As GaNAs semiconductor and quantum structure leads to the suppression of Auger non-radiative recombination and significant enhancement of emission rates. Progress in dilute-anion III-nitrides will be further discussed.

Biography Chee-Keong Tan is an Assistant Professor in the Department of Electrical and Computer Engineering at Clarkson University. He obtained his Ph.D. in Electrical Engineering from the Lehigh University in 2016 and his B.Eng. in Electrical Engineering from the University of Sheffield in 2011. His research has focused on semiconductor materials and nanostructures for electronic and optoelectronic devices applications. Tan has extensive experience in semiconductor materials design especially in wide and ultrawide bandgap semiconductors, such as dilute- anion III-Nitride and III-Oxide based materials. Specifically, he has established foundational work in dilute-anion III-Nitride field, bringing up novel concepts that provide breakthrough from fundamental bottlenecks in conventional III- Nitrides. Dr. Tan has authored or co-authored over 100 refereed journal publications and conference presentations in total.

Page- 21 GSELOP2021 Global Summit and Expo on Laser, Optics and Photonics August 23-25, 2021 | Paris, France

Mohammad Hafezi University of Maryland,USA

Nonlinear and Quantum Topological Photonics Abstract The introduction of topological physics in photonic systems has provided a new paradigm to engineer the flow of photons, and thereby, design photonic devices with novel functionalities and inherent robustness against fabrication disorders. In this talk, we discuss several examples of such ideas from making robust photonic crystal tapers, to generation of pairs of photons and frequency combs. Specifically in the latter example, we use topological design principles to theoretically propose a new class of optical frequency combs, based on a two-dimensional array of coupled ring resonators that creates a synthetic magnetic field for photons and exhibits topological edge states. We show that these topological edge states constitute a travelling-wave super-ring resonator that leads to the generation of coherent nested optical frequency combs, and self-formation of nested temporal solitons and Turing rolls that are remarkably phase-locked over >40 rings. In the nested soliton regime, our system operates as a pulsed optical frequency comb and achieves a mode efficiency of > 50%, an order of magnitude higher than single ring frequency combs that are theoretically limited to only ∼ 5%.

Tunable quantum interference using a topological source of indistinguishable photon pairs, V. Vikram Orre, S. Mittal, E. A. Goldschmidt, and M. Hafezi, Nature Photonics (2021)

Topological Frequency Combs and Nested Temporal Solitons, S. Mittal, G. Moille, K. Srinivasan, Y. K. Chembo, and M. Hafezi, arXiv preprint arXiv:2101.02229 (2021) accepted in Nature Physics.

Page- 22 GSELOP2021 Global Summit and Expo on Laser, Optics and Photonics August 23-25, 2021 | Paris, France Z. Shen School of Electronic and Optical Engineering, Nanjing University of Science and Technology, Nanjing 210094, Jiangsu, China. *[email protected]

Metalenses/Metasurfaces for Beam Shaping and Optical Trapping/Manipulation/Sorting

Abstract Metalenses/metasurfaces have attracted much attention. They have shown excellent flexibility for manipulating the phase, amplitude, polarization, and angular momentum of light. They have great potential in beam shaping and optical trapping/manipulation/sorting. In this talk, I will first introduce our work of metalenses/metasurfaces for beam shaping: (1) Polarization-insensitive beam splitters with variable split ratios based on phase gradient metasurfaces. (2) Few-layer metasurface with gold split-rings for high-efficiency asymmetric circular polarization conversion. (3) Generation of optical vortices with polarization-insensitive metasurfaces. (4) Numerical study on the tight focusing of radially polarized beams with polarization-insensitive metalenses. (5) Generation of needle beams through focusing of azimuthally polarized vortex beam by polarization-insensitive metasurfaces. I will secondly introduce our work of metalenses/metasurfaces for optical trapping/manipulation/sorting: (1) Optical manipulation of Rayleigh particles by metalenses-a numerical study. (2) Optical trapping and separation of metal nanoparticles by cylindrical metalenses with phase gradients. (3) Optical spanner for nanoparticle rotation with focused optical vortex generated through Pancharatnam- Berry phase metalens.

Keywords Metalens, Metasurfaces, beam shaping, structured light, optial tweezers, optical trapping

Biography Dr. Zhe Shen received both Bachelor's and Master's degrees in optical engineering from Nankai University, and Ph. D. with Prof. Yaochun Shen from University of Liverpool. He is an associate professor at Nanjing University of Science and Technology. He was a member of SPIE and is currently a member of COS and CSOE. He has served as a reviewer for more than 15 reputed journals. He has published more than 25 papers in reputed journals and has been served as an editorial board member of American Journal of Optics and Photonics. His research interests include Optical tweezers, Plasmonics, Metasurfaces, Beam shaping, SERS.

Page- 23 GSELOP2021 Global Summit and Expo on Laser, Optics and Photonics August 23-25, 2021 | Paris, France H.Zia1* 1University of Twente, Department Science & Technology, Laser Physics and Nonlinear Optics Group, MESA+ Research Institute for Nanotechnology, Enschede 7500 AE, The Netherlands *[email protected]

Enhanced Spectral Generation and Duration Compression in Alternating Dispersion Waveguides

Abstract This invited talk will present recent advances in longitudinal sign-alternating dispersion waveguides for supercontinuum generation (SCG) and nonlinear pulse compression. The general concept of dispersion alternation for overcoming mechanisms that stop spectral generation in dispersive media will be shown. For example, Fig. 1a[1],is a numerical illustration of the spectral development within sign-alternating dispersion waveguides, as compared to the conventional uniform dispersion SCG. In sum, sign-alternating dispersion SCG dramatically maximizes the ratio of final bandwidth to input peak power of the optical radiation, enhancing efficiency. Also discussed is how sign-alternation of dispersion enables efficient pulse compression, through the obtained enhancement of bandwidth to input peak power. Thus, the concept is ideally implemented in integrated photonics, where nonlinear pulse compression can still take place, even with the constraint of an exceedingly low pulse peak power [2]. New phase effects that contribute to a higher pulse compression factor also emerge and will be shown. Figure 1b, taken from [2], indicates a numerical example in the SiNintegrated photonic setting, where, alternating the sign of dispersion contributes to a high pulse duration compression. Experimental results backing these numerical results will also be shown in the talk. a) b)

Keywords supercontinuum, pulse compression, nonlinear integrated photonics& waveguides

Page- 24 GSELOP2021 Global Summit and Expo on Laser, Optics and Photonics August 23-25, 2021 | Paris, France

References [1] H. Zia, N.M. Lüpken, T. Hellwig, C. Fallnich, K.-J. Boller, "Supercontinuum Generation in Media with Sign‐Alternated Dispersion, Laser Photonics Rev., vol. 6, pp. 2000031, 2020. [2] H. Zia, “Enhanced Pulse Compression within Sign-Alternating Dispersion Waveguides,” Photonics, 8(2).

Page- 25 GSELOP2021 Global Summit and Expo on Laser, Optics and Photonics August 23-25, 2021 | Paris, France Lothar Moeller SubCom, Eatontown, NJ 07724, USA [email protected] Long-range Nonlinear Optical Interactions in Standard Single Mode Fiber Abstract Precise modeling of NL signal propagation in optical fiber is critical for maximizing the data capacity of long-haul communication systems. It balances signal powers and received OSNR to mitigate nonlinearities.

Over the past five decades simplified techniques have been developed to efficiently compute NL propagation in SSMF. They adapt models for piece-wise isotropic fiber segments to simulate propagation paths with randomly varying birefringence (Manakov-PMD equation1).

Recently, a novel transmission phenomenon in fiber to which we refer to as NL DePolarization (NLDP) has been introduced. Unpolarized ASE depolarizes a co-propagating probe due to the fiber Kerr nonlinearity. This phenomenon eludes from aforementioned propagation modeling.

NLDP is based on long-range NL interactions where contributions from Kerr nonlinearities interfere over long transmission distances. Counterintuitively, the NL-generated Stokes vector spectrum of a signal’s polarization narrows with increasing propagation length2.

We discuss experimental results of NLDP and its implications for the mathematical modeling of light propagation in SSMF.

Fig. 1: left) Stokes vector spectrum of a probe signal after 1 to 20 Mm transmission. right) Optical receive spectra of ASE and an embedded probe for same transmission distances.

Keywords Nonlinear propagation, fiber, Kerr nonlinearity, Manakov Equation, polarization

Page- 26 GSELOP2021 Global Summit and Expo on Laser, Optics and Photonics August 23-25, 2021 | Paris, France

References [1] D. Marcuse, C. Menyuk, P.K.A. Wai, “Application of the Manakov-PMD Equation to Studies of Signal Propagation in Optical Fibers with Randomly Varying Birefringence,” J. Lightwave Technol. 15, pp. 1735-1746, (1997).

[2] L. Moeller, “Stokes Vector Scattering induced by Nonlinear Depolarization of Light in Fiber,” ECOC’20, (2020).

Biography Lothar Moeller is with SubCom, a leading provider for undersea communication systems. He was with Bell Labs Research, Holmdel, US from 1997 to 2014 and received his PhD in electrical engineering from Swiss Federal Institute of Technology in 1996.

Page- 27 GSELOP2021 Global Summit and Expo on Laser, Optics and Photonics August 23-25, 2021 | Paris, France Ronen Rapaport1, 2,*

1)Racah Institute of Physics, The Hebrew University of Jerusalem, Jerusalem 9190401,Israel 2)The Center for Nanoscience and Nanotechnology, The Hebrew University of Jerusalem,Jerusalem 9190401,Israel *[email protected] Overcoming the Rate-Directionality Tradeoff: Room- Temperature Ultrabright Single Photon Sources Abstract

Deterministic GHz-rate single photon sources at room-temperature would be essential components for various quantumapplications. However, both the slow intrinsic decay rate and the omnidirectional emission of typical quantum emittersare two obstacles towards achieving such a goal which are hard to overcome simultaneously. We solve this challengeby a hybrid approach, using a complex monolithic photonic resonator constructed of a gold nanocone responsiblefor the rate enhancement, enclosed by a circular Bragg antenna for emission directionality. A repeatable process accuratelybinds colloidal quantum dots to the tip of the antenna-embedded nanocone. As a result we achieve simultaneous 20-foldemission rate enhancement and record-high directionality leading to an increase in the observed brightness by a factoras large as 450 (80) into an NA = 0.22 (0.5). We project that these miniaturised on-chip devices can reach photon ratesapproaching 1.4×108 single photons/second thus enabling ultrafast light-matter interfaces for quantum technologies at ambient conditions.

Keywords Single photon sources, quantum dots, quantum optics, quantum information, plasmonics, colloidal nanocrystals

References [1] Abudayyeh et al., arXiv preprint arXiv:2010.15016, (2020) [2] Abudayyeh, et al., APL Photonics 6, 036109 (2021) [3] Abudayyeh, et al., ACS Photonics 6, 446 (2019) Page- 28 GSELOP2021 Global Summit and Expo on Laser, Optics and Photonics August 23-25, 2021 | Paris, France

[4] Hamza Abudayyeh and Ronen Rapaport, Quantum Sci. Technol. 2 034004 (2017)

Biography Ronen Rapaport is a Professor at the Racah Institute of Physicsat the Hebrew University of Jerusalem, Israel. Ronen has received his PhD in Physics from the Technion, Israel in 2001, where he studied the physics of exciton polaritons. Ronen then became a principle investigator (MTS) at the Optical Physics department, Bell Laboratories,where he conducted research in various fields related to quantum nano-structures of semiconductors until 2007. Since 2007 Ronen is leading the Nanophotonics of quantum structures Lab, with research ranging formmany-body quantum physics of cold quantum liquids of excitons and polaritons in low dimensional quantum structures, to light- matter coupling of quantum emitters, nano- and quantum-optical device physics.

Page- 29 GSELOP2021 Global Summit and Expo on Laser, Optics and Photonics August 23-25, 2021 | Paris, France T. Taliercio1* P. Loren1, J. Guise1, F. Barho1, E. Alvear-Cabezon2, P. Felhen3, M. Najem1,F. Gonzalez-Posada-Flores1, S. Blin1, L. Cerutti1, R. Smaali2, E. Centeno2and T. Taliercio1*

1IES, Univ Montpellier, CNRS, Montpellier, France. 2Universite Clermont Auvergne, CNRS, SIGMA Clermont, Institut Pascal,F-63000 Clermont- Ferrand, France. 3NSE3 (CNRS UMR3208) Institut franco-allemand Saint-Louis *[email protected]

Semiconductor Plasmonics for Bio-sensing and Active Plasmonics

Abstract Plasmonics is one of the main fields of nanophotonics exploiting the coupling between photons and the collective oscillations of free carriers at metallic surfaces or nanostructures.The surface plasmon polariton is the resulting quasi-particle with a strong electric field confinement and huge electricfield enhancement at the metal surface. These main features offer potential applications from biosensing to solar cell technologies. Heavily doped semiconductors, such as InAs or Ge, are designed metalsallowing to control their plasmonic properties from the THz up to the mid-infrared spectral range.

We will demonstrat that it is possible to employ semiconductorsfor plasmonics by chemical or optical doping. The perfect absorbers (PA) fabricated with doped semiconductors (chemical doping) can be exploited fortheir biosensing properties toeither enhancethe absorption of rotavibrational modes of molecules with surface-enhanced infrared absorption (SEIRA) spectroscopy [1] or enhance the thermal emission of molecules with surface-enhanced thermal emission spectroscopy (SETES)[2]. The optical doping will be applied toundoped semiconductor slabs.Photo-generating free carriers in semiconductors,givesthe possibility to restore a metallic behavior. In this case, plasmonic behavior is possible in the THz range.The transmitted THz beam through the semiconductor slab can be photo-modulated by a laser with a wavelength of 800 nm until a few MHz [3].

Keywords Heavily doped semiconductor, Biosensing, active plasmonics, mid-infrared spectroscopy

References [1] F. B. Barho,et al., Adv. Optical Mater. 1901502 (2020). [2] F. B. Barho, et al.,ACS Photonics 6, 1506−1514 (2019). [3] E. Alvear-Cabezon, et al., Appl. Phys. Lett. 117, 111101 (2020).

Page- 30 GSELOP2021 Global Summit and Expo on Laser, Optics and Photonics August 23-25, 2021 | Paris, France

Biography Thierry Taliercio is a full professor at the University of Montpellier. He is head of the NanoMIR group and the Electrical Engineer teaching department since September 2019. He is a specialist of all- semiconductor plasmonics for infrared applications and of the optical properties of semiconductor nanostructures. He currently study the interest of heavily doped semiconductors for bio-sensing and active plasmonics in the mid-IR and THz spectral range.

Page- 31 GSELOP2021 Global Summit and Expo on Laser, Optics and Photonics August 23-25, 2021 | Paris, France Jos Haverkort Department or Applied Physics, Eindhoven University of Technology, Eindhoven, The Netherlands, [email protected] Light Emission from Hexagonal Sige

Abstract It has been a holy grail for several decades to demonstrate direct bandgap light emission in silicon. Both silicon and germanium are known to be indirect bandgap semiconductors. However, by transforming Si and Ge to the hexagonal crystal phase, the L-minimum is folded towards the Γ-point, yielding a direct bandgap arrangement.

Here we report light emission1 from hexagonal crystal phase SiGe. Extrapolations between Hex-Si and Hex-Ge predict that Hex-SiGe will be a direct bandgap semiconductor at Ge-compositions above 65%. We measured the photoluminescence spectra of Hex-Ge as a function of excitation power and temperature. Importantly, the spectra can be interpreted as being exclusively due to band-to-band recombination. We subsequently investigated the photoluminescence spectra of Hex-SiGe as a function of the composition. We observe a broad tunability of the direct bandgap between 1.8 μm at 0.65% Ge and 3.5 μm at 100% Ge, measured at 4K. Importantly, we observe a subnanosecond recombination lifetime in Hex-SiGe, which can be explained by a breaking of the translational symmetry due to alloying. Moreover, we observe a temperature independent photoluminescence efficiency in the full temperature window between 4K and 300K, which demonstrates that the recombination mechanism in Hex-SiGe is purely radiative. For serving as a Si-compatible light emitter, the radiative efficiency at room temperature is most important. We observe a very high radiative recombination efficiency which is comparable to a III/V semiconductor.

Reference: 1. Nature, 580, 205 (2020)

Biography Jos Haverkort obtained his PhD at Leiden University in 1987and is currently an Associate Professor at Eindhoven University of Technology in the Netherlands. He has been focusing on the optical properties of III/V semiconductors, which recently turned into the study of hexagonal GaP nanowires (NWs), orange emitting hexagonal InGaP NW-shells, green emitting hexagonal AlInP NWs and presently hexagonal SiGe NWs. Hexagonal SiGe is a direct bandgap semiconductor which efficiently emits light between 1.8 and 3.5 micron. This new semiconductor is very promising for chip to chip an eventually intra-chip optical communication as well as for infrared optical sensors.

Page- 32 GSELOP2021 Global Summit and Expo on Laser, Optics and Photonics August 23-25, 2021 | Paris, France Vincenzo Giannini Technology Innovation Institute, Masdar City, Abu Dhabi, United Arab Emirates Instituto de Estructura de la Materia (IEM-CSIC), Consejo Superior de Investigaciones Cientı́ ficas, Madrid, Spain

Extraordinarily Transparent Compact Metallic Metamaterials Abstract Metals are highly opaque, yet we show numerically and experimentally that densely packed arrays of metallic nanoparticles can be more transparent to infrared radiation than dielectrics such as germanium, even for arrays that are over 75% metal by volume. Despite strong interactions between the metallic particles, these arrays form effective dielectrics that are virtually dispersion-free, making possible the design of optical components that are achromatic over ultra-broadband ranges of wavelengths from a few microns up to millimetres or more. Furthermore, the local refractive indices may be tuned by altering the size, shape, and spacing of the nanoparticles, allowing the design of gradient-index lenses that guide and focus light on the microscale (see figure a). The electric field is also strongly concentrated in the gaps between the metallic nanoparticles, and the simultaneous focusing and squeezing of the electric field produces strong ‘doubly-enhanced’ hotspots (see figure b) which could boost measurements made using infrared spectroscopy and other non-linear processes over a broad range of frequencies, with minimal heat production. References [1] Extraordinarily transparent compact metallic metamaterials. Nature Communications (2019) 10:2118 | https://doi.org/10.1038/s41467-019-09939-8.

Page- 33 GSELOP2021 Global Summit and Expo on Laser, Optics and Photonics August 23-25, 2021 | Paris, France S.Fiedler1,2* S.Fiedler1,2*, S. Morozov2,L. Illiushyn3,4, S. Boroviks2, T.J. Booth3,4, N. Stenger4,5, C. Tserkezis2, C. Wolff2, and N.A.Mortensen2,4,6

1Federal Institute for Materials Research and Testing, Biophotonics, Richard-Willstätter-Straße 11, 12489 Berlin, Germany. 2Center for Nano Optics, University of Southern Denmark, Campusvej 55, 5230 Odense M, Denmark. 3Department of Physics, Technical University of Denmark, 2800 Kongens Lyngby, Denmark. 4Center for Nanostructured Graphene, Technical University of Denmark, 2800 Kongens Lyngby, Denmark. 5Department of Photonic Engineering, Technical University of Denmark, 2800 Kongens Lyngby, Denmark. 6Danish Institute for Advanced Study, University of Southern Denmark, Campusvej 55, 5230 Odense M, Denmark. *[email protected]

Giant Photon Bunching of WS2 Monolayer in Cathodoluminescence

Abstract In this work, tungsten disulfide (WS2) monolayers encapsulated in hexagonal boron nitride (hBN) with/without monocrystalline Au nanodisks (NDs) have been systematically studied, using CL and PL spectroscopy as well asg(2)-autocorrelation-measurements in CL and PL. CL and PL maps of WS2monolayersshow a narrow peak at ~625 nm without any background emission. Here, hBNnot only protects WS2 from the electron beam but also acts as a charge carrier sink,significantly increasing the CL signal [1]. Further CL enhancement is achieved by Au ND deposition, exhibiting the maximum at the center of the NDs,independent of their size, while PL intensity is unaffected. This indicates thatPurcell enhancementcannot be the underlying effect.

Page- 34 GSELOP2021 Global Summit and Expo on Laser, Optics and Photonics August 23-25, 2021 | Paris, France

AgiantCL -photon bunching of hBN-encapsulated WS2 is found,independent of the applied voltage but highly dependent on the electron beam current.At lowest current of ~2 pA, a CL bunching factor of up to 160 is observed. Varying thicknesses of the surrounding hBNchanges the overall CL signal but does not affect the bunching factor, though small local changes within the same monolayer can be found.In contrast, there is no PL correlation (g(2)(0) = 1).

Interestingly, this photon bunching can be further increased by Au NDs, resulting in the highest ever observed bunching factor of close to 2200. Once again, this enhancement is independent of the Au ND’s diameter although some disks show higher bunching factors than others. Most likely, the Au acts as shield for the incoming primary electrons, resulting in an even further decreased current, and thereby, increased bunching.

Keywords Cathodoluminescence, g2, photon bunching, WS2 monolayer,Au nanoparticles

References [1] S. Zheng, J.-K. So, F. Liu, Z. Liu, N. Zheludev, H.J. Fan, Nano Lett., 17, 6475-6480 (2017)

Page- 35 GSELOP2021 Global Summit and Expo on Laser, Optics and Photonics August 23-25, 2021 | Paris, France P. Boucaud3,* M. Gromovyi1, M. El Kurdi1, E. Herth1, X. Checoury1, F. Tabataba-Vakili2, N. Bhat3, S. Chenot3, A. Courville3, E. Frayssinet3, B. Damilano3, B. Alloing3, F. Semond3, P. Boucaud3,*

1Centre de Nanoscienceset de Nanotechnologies, Université Paris-Saclay, CNRS, Palaiseau, France. 2Faculty of Physics, Ludwig-Maximilians-UniversitatMunchen (LMU), Munich, Germany. 3CRHEA,Université Côte d’Azur, CNRS, Rue Bernard Gregory, Sophia-Antipolis, France. *[email protected]

Epitaxially-Grown III-N Semiconductors for On-Chip Photonic Circuits Abstract In this presentation, we will review the recent progress achieved with epitaxially-grown III-N semiconductors for integrated on-chip photonic circuits. The III-N semiconductors can be epitaxially- grown on sapphireor siliconsubstrates. Growth of III-N semiconductors on 8-inches silicon substrates is routinely available, thus opening the route for their integration in a CMOS environment.The III-N semiconductors exhibit a large transparency window from the UV spectral range to the near- infrared. Active emitters, with quantum wells or quantum dots can be monolithically integrated in stacked heterostructures, thus offering a decisive advantage over other platforms performing in the visible range. The lattice symmetry of III-N semiconductors allows for second-order and third-order nonlinearities. It is as well an asset for nonlinear integrated photonics and devices for quantum technologies. We will show how the epitaxially-grown III-N heterostructures can be transferred on oxide on silicon. Microring resonators with state-of-the-art performances will be presented. We will discuss the perspectives opened by these materials for integrated photonics and the achievement of optical parametric oscillators. Keywords III-N semiconductors, photonic circuits, nonlinear integrated photonics Biography Philippe Boucaud graduated from Écolenormalesupérieure de Saint-Cloud, now Écolenormalesupérieure de Lyon, in France. He obtained the « Agrégation de physique » in 1988. He received a master degree in condensed matter physics in 1987. He has obtained a PhD from University Paris Sud in physics and engineering in 1992. He is since 1993 research fellow at French national scientific research center (CNRS), senior research associate since 2010. He has been a visiting researcher at university of California Santa Barbara in 1999. His research activities focus on condensed matter physics, optoelectronics, and integrated photonics.

Philippe Boucaudis since 2018 head of Research Center on Hetero-Epitaxy and its Applications (CRHEA - http://www.crhea.cnrs.fr/) Page- 36 GSELOP2021 Global Summit and Expo on Laser, Optics and Photonics August 23-25, 2021 | Paris, France Béatrice Dagens1* Béatrice Dagens1*, Giovanni Magno1,2, Vy Yam1 1Université Paris-Saclay, Centre de Nanosciences et de Nanotechnologies, 91120, Palaiseau, France 2now withDipartimento di Ingegneria Elettrica e dell’Informazione, Politecnico di Bari, Bari, Italy *[email protected]

Localized Surface Plasmons for Photonic Integrated Circuits Abstract Localized surface plasmons (LSP) result from the electromagnetic excitation in metallic structure with typical dimensions lower than the wavelength. The excited dipole in a plasmonic nanoparticle radiates in return an electromagnetic wave of the same frequency, which can excite another plasmonic nanostructure with similar resonance: plasmonic nanostructures assembly may support collective resonances, and/or propagate energy from one to the next [1]. Such a plasmonic waveguide can be coupled to a dielectric waveguide, in a structure which enables very efficient excitation of LSP and thus integration of miniaturized photonic/plasmonic functions [2].

We will present here the generic structure allowing the successful integration of localized surface plasmon in photonic circuits, and we will then detail a few examples of such functions as schematized

(a) (b)

Page- 37 GSELOP2021 Global Summit and Expo on Laser, Optics and Photonics August 23-25, 2021 | Paris, France

(c)

Figure 1. Integrated LSP chains for efficient (a) tunable nanoantennas, (b) plasmonic tweezers and (c) plasmonic sensors. in Fig. 1, liketunable nanoantennas, plasmonic tweezers [3] or plasmonic sensors. Keywords plasmonics, photonic integrated circuits, plasmonic tweezer, nanoantenna

References [1] A. Femius Koenderink and Albert Polman, “Complex response and polariton-like dispersion splitting in periodic metal nanoparticle chains,” Phys.Rev.B, 74,033405, 2006 [2] M. Février, P. Gogol, A. Aassime, R. Mégy, C. Delacour, A. Chelnokov, A. Apuzzo, S. Blaize, J.- M. Lourtioz, and B. Dagens, “Giant Coupling Effect between Metal Nanoparticle Chain and Optical Waveguide,” Nano Letters 2012, 12 (2), pp 1032–1037 [3] A. Ecarnot, G. Magno, Vy Yam, B. Dagens, “Ultra efficient nanoparticles trapping by integrated plasmonic dimers,” Optics Letters, 43(3), 2018

Biography Béatrice Dagens is CNRS Senior Researcher at Centre for Nanoscience and Nanotechnology (C2N), in Paris-Saclay University. Her current research focuses on magneto-optical, magneto- photonic and plasmonic nanostructured components for compact integrated photonic circuits or planar devices (for, telecom, visualization or holography applications). Before joining CNRS in 2007, she obtained a PhD degree in Optoelectronics from the University Paul Sabatier (Toulouse) in 1995 and then she has worked for eleven years at Photonic Device department in Alcatel, on semiconductor optical amplifier based interferometers, on quantum dots, dilute nitride, and metallic ferromagnetic layers based laser diodes and on Photonics Integrated Circuits. Since 2012 she has hold the chair of University Paris-Sud “Optoelectronics and Photonics”, funded by PSA, and then the OpenLab “PhOVeA” (Photonics and Optoelectronics for Vehicle and Automotive), a common research structure with PSA (now Stellantis).

Page- 38 GSELOP2021 Global Summit and Expo on Laser, Optics and Photonics August 23-25, 2021 | Paris, France Alex Hayat1* Shlomi Bouscher1, Dmitry Panna1, Krishna Balasubramanian1, Ronen Jacovi1, Ankit Kumar1, Christian Schneider2, Sven Hoefling2 and Alex Hayat1* 1. Department of Electrical Engineering, Technion, Haifa 32000, Israel 2. Technische Physik, Universität Würzburg, D-97074 Würzburg, Germany *[email protected] Superconductor-Semiconductor Quantum Optoelectronics Abstract We have experimentally demonstrated a superconducting light-emitting diode (SLED). The superconductor serves as a reservoir of spin-entangled electron-pairs (Cooper-pairs). It has been proposed that Cooper-pairs injected into the pn junction, can recombine with a pair of holes, and emit an entangled photon pair [1]. Such injection of Cooper-pairs into the pn junction is evident through the process of Andreev reflection, which manifests itself as an enhancement of electric conduction below the superconducting gap [2]. Moreover, Cooper-pair recombination has also been shown to result in enhanced emission below the superconductor’s critical temperature Tc. Our latest SLED design (Fig 1a) exhibits both Andreev reflection in its conductance spectrum (Fig 1b). We have also observed photon-pair correlations g(2) (Fig 1b) and higher-order correlations g(4) (Fig 1c), with temperature dependence on the order parameter

∆ - in good agreement with calculations, with (2)(0)~∆2(𝑇 and < �(4) > ~∆4(�), corresponding to photon-pair emission from injected Cooper pairs.

Furthermore, incorporation of high-temperature (high-Tc) superconductors can greatly increase operating temperatures to well above LN2 (~77K), thus paving the way for a broad range of commercial applications. We have achieved an important milestone in this direction through the design and fabrication of YBCO/GaN superconductor-semiconductor junctions [3], and have recently observed strong Andreev reflection [4]. These results open new directions for fundamental studies in quantum optics and light-matter interaction and enable a wide range of applications in quantum technologies and quantum information processing.

Fig. 1 (a) SLED structure in EL emission configuration. Current is injected through the upper Nb electrode into the PN junction. Due to the opaqueness of the Nb contact, emission (wavy yellow lines) is only observed from the edges of the contact (the inset shown emission from such contact). (b) Andreev reflection in the SLED structure. A strong zero-bias peak is observed, decreasing as temperature increasing up to the critical temperature of the superconductor. (c) g(2)(0) vs. temperature with the calculated dependence. (d) < g(4)>-1 vs. temperature with a calculated dependence. Page- 39 GSELOP2021 Global Summit and Expo on Laser, Optics and Photonics August 23-25, 2021 | Paris, France

References [1] A. Hayat, et al, Phys. Rev. B 89, 094508 (2014) [2] D. Panna, S. Bouscher, K. Balasubramanian, V. Perepelook, S. Cohen, D. Ritter, and A. Hayat, Nano Letters, 18, 6764 (2018). [3] D. Panna, K. Balasubramanian, S. Bouscher, Y. Wang, P. Yu, X. Chen and A. Hayat, Nature Sci. Rep. 8, 5597 (2018). [4] S. Bouscher, Z. Kang, K. Balasubramanian, D. Panna, P. Yu, X. Chen and A. Hayat, J. Phys. Condens. Matter 32 475502 (2020).

Page- 40 GSELOP2021 Global Summit and Expo on Laser, Optics and Photonics August 23-25, 2021 | Paris, France J. Osterholz* D. Heunoske, M. Lück, M. Wickert, and J. Osterholz* Fraunhofer Institute for High-Speed Dynamics, Ernst-Mach-Institut, EMI, Ernst-Zermelo-Str. 4, 79104 Freiburg, Germany. *[email protected]

Spectroscopic and Interferometric Investigation of Plasma Dynamics in High- Power cw Laser-Matter Interaction Abstract Continuous-wave (cw) lasers are established tools for a wide variety of applications. While laser systems with a power of several kW up to a few 10 kW are being used since many years, lasers with a much higher power up to the range of 100 kW are currently becoming available. Besides the laser power the beam diameter is a parameter of central importance since the interaction process strongly depends on the laser intensity on the sample. While laser material processing typically uses beam diameters in the sub-millimeter range, there are specific applications, e.g. in security research [1] or geology [2], which are carried out at larger diameters in the millimeter to centimeter range.

The work in this presentation focuses on laser intensities where the interaction is characterized by the formation of a plasma cloud close to the interaction zone. The knowledge of the dynamics of the plasma formation and expansion is essential for the detailed understanding of the interaction process and for the energy transfer to the sample. These aspects are analyzed for the case of metal samples irradiated with laser powers up to 10 kW. The study combines high-speed video- diagnostics, time- and spatially resolved spectroscopy, and interferometry to allow for a comprehensive characterization of the plasma properties. It is demonstrated how the key plasma parameters including electron temperature and density can be derived from the experimental data and how the plasma formation affects the overall interaction process. Finally, the potential of the presented diagnostic techniques for an application at higher powers is discussed.

Keywords High-Power Lasers, Laser-Matter Interaction, Spectroscopy, Interferometry, High- Speed Video, Plasma Dynamics

References [1] J. Osterholz et al., Neutralization of improvised explosive devices by high-power lasers: Research results from the FP7 project ENCOUNTER, Proc. of SPIE 9990, 999001, doi: 10.1117/12.2241083 (2016). [2] C. Hamann et al., Correlating laser-generated melts with impact-generated melts: An integrated thermodynamic-petrologic approach, Geophys. Res. Lett. 43, 10,602-10,610, doi:10.1002/2016GL071050 (2016).

Biography Jens Osterholz is working at EMI since 2009 and is head of the Impact Physics department since 2019. He has received his PhD in Physics from the University of Duesseldorf in 2002 and his Diploma in Physics from the University of Muenster in 1999. From 2002-2009 he was working in the field of high-power laser science at the University of Duesseldorf. In 2006 he was awarded a one- year research fellowship at the University of Texas at Austin. Page- 41 GSELOP2021 Global Summit and Expo on Laser, Optics and Photonics August 23-25, 2021 | Paris, France Daan Lenstra1 Daan Lenstra1, Alexis Fischer2,3,Amani Ouirimi2,3, Alex Chamberlain Chime2,3,4, Nixson Loganathan2,3, Mahmoud Chakaroun2,3

1Institute of Photonics Integration, Eindhoven University of Technology, P.O. Box 513, 5600MBEindhoven, The Netherlands; [email protected] 2Universite Sorbonne Paris Nord, Laboratoire de Physique des Lasers, UMR CNRS 7538, 99 avenue JB Clement, 93430 Villetaneuse-F 3Universite Sorbonne Paris Nord, Centrale de Proximite en Nanotechnologies de Paris Nord, 99 avenue JB Clement, 93430 Villetaneuse-F 4Universite de Dschang, IUT-FV de Bandjoun, Cameroon

Ultra-Short Optical Pulse Generation in a Micro OLED

Abstract In order to confirm that a future of organic optoelectronics could be “far beyond display and lighting” applications, we present results of a study of μ-OLED devices under nanosecond and sub- nanosecond electrical pulse excitation.

We report preliminary investigations with high-speed μ-OLEDs and demonstrate very promisingoptical pulse responses as short as 800ps using Alq3:DCM, see Figure 1. These sub-ns optical responses give strong indication that a scientific and technological revolution is at hand with ultrafast dynamics in organic optoelectronics. The measurements are for in-house fabricated μ-OLEDs both with cavity and without cavity.Two types of device are considered, namely small molecule OLED (smOLED) and polymer OLED (pOLED), with different sizes from 25µmx100µm and 100µm x 100µm.

With a validated model based on seven rate equations for an electrically pumped OLED [1], we simulate the generation of ultra-short optical pulses. The model applies to a host-guest system and includes Stoke-shifted reabsorption and field-dependent Langevin recombination. For the Alq3:DCM system we compare the results with the above-mentioned measurements. The good agreement between the measurement and the simulation is the basis for further study of the prospects for ultra- short dynamics on the ps time scale.

The results strongly confirm the promise of a scientific and technological revolution with the ultra- fast dynamics of organic optoelectronics, exceeding state-of-the-art results for GaN μ-LEDs and OLEDs [2,3].

[1]Ouirimi, A., Chime, A. C., Loganathan, N., Chakaroun, M., Fischer, A. P. A., Lenstra, D. Threshold estimation of an Organic Laser Diode using a rate-equation model validated experimentally with a microcavity OLED submitted to nanosecond electrical pulses. Organic Electronics2021, in print, https://doi.org/10.1016/j.orgel.2021.106190. [2] M. S. Islim et al., “Towards 10Gb/s orthogonal frequency division multiplexingbased visible light communication using a GaN violet micro-LED,” Photon. Res., PRJ, vol. 5, no. 2, pp. A35–A43, Apr. 2017, doi: 10.1364/PRJ.5.000A35.

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[3] K. Yoshida et al., “245 MHz bandwidth organic light-emitting diodes used in agigabit optical wireless data link,” Nat Commun, vol. 11, no. 1, Art. no. 1, Mar. 2020, doi: 10.1038/s41467-020- 14880-2.

Figure 1. Preliminary measurement showing an 800 ps optical response emitted by an Alq3:DCM based μ-OLED.The blue curve is the excitation voltage (left scale) and the orange curve is the emitted light (arbitrary units).

Page- 43 Virtual Presentations GSELOP2021 Global Summit and Expo on Laser, Optics and Photonics August 23-25, 2021 | Paris, France Yuri Kivshar Nonlinear Physics Center, Australian National University, Australia

Metaphotonics and Metasurfaces Abstract Metamaterials were initially suggested for the realization of negative-index media, and later they became a paradigm for engineering electromagnetic space and controlling propagation of waves. However, applications of metamaterials in optics are limited due to inherent losses in metals employed for the realization of artificial optical magnetism. Recently, we observe the emergence of a new field of all-dielectric resonant metaphotonicsaiming at the manipulation of strong optically-induced electric and magnetic Mie-type resonances in dielectric nanostructures with high refractive index. Unique advantages of dielectric resonant nanostructures over their metallic counterparts are low dissipative losses and the enhancement of both electric and magnetic fields that provide competitive alternatives for some problems in plasmonics including optical nanoantennas, biosensors, active metasurfaces, and metadevices. This talk will highlight some recent advances in all-dielectric Mie-resonant metaphotonics including active and nonlinear nanophotonics as well as the recently emerged fields of topological photonics.

Biography Yuri Kivshar received PhD in 1984 in Kharkov (Ukraine). From 1988 to 1993 he visited and worked at several research centers in the USA and Europe, and in 1993 he moved to Australia where he established Nonlinear Physics Center. His research interests include nonlinear physics, metamaterials, and nanophotonics. He is Fellow of the Australian Academy of Science, OSA, APS, SPIE, and IOP. He received several international awards including Pnevmatikos Prize in Nonlinear Science (Greece), Lyle Medal (Australia), Lebedev Medal (Russia), The State Prize in Science and Technology (Ukraine), Harrie Massey Medal (UK), Humboldt Research Award (Germany), and 2020 SPIE Mozi Award (USA).

Page- 45 GSELOP2021 Global Summit and Expo on Laser, Optics and Photonics August 23-25, 2021 | Paris, France Chennupati Jagadish Chennupati Jagadish, AC, MNAE (US), FAA, FTSE, FTWAS, FNAI, FNA, FNAE, FASc, FAPAS, FEurASc, FNASc

Research School of Physics The Australian National University Canberra, ACT 2601, Australia Email: [email protected] Semiconductor Nanostructures for Optoelectronics, Energy and Neuroscience Applications

Abstract Semiconductors have played an important role in the development of information and communications technology, solar cells, solid state lighting. Nanowires are considered as building blocks for the next generation electronics and optoelectronics. In this talk, I will present the results on optoelectronic devices such as lasers/LEDs, THz detectors, energy devices such as solar cells, photoelectrochemical (PEC) water splitting and Neuro-electrodes. Future prospects of the semiconductor nanowires will be discussed.

Biography Professor Jagadish is a Distinguished Professor and Head of Semiconductor Optoelectronics and Nanotechnology Group in the Research School of Physics, Australian National University. He is currently serving as Past President of IEEE Photonics Society. Prof. Jagadish is the Editor-in-Chief of Applied Physics Reviews (IF:17.05), Editor of 3 book series and serves on editorial boards of 19 other journals. He has published more than 960 research papers (680 journal papers), holds 5 US patents, co-authored a book, co-edited 15 books and edited 12 conference proceedings and 18 special issues of Journals. He is a fellow of 11 Science and Engineering Academies (US, Australia, Europe, India) and 14 Professional Societies (IEEE, MRS, APS…). He received many awards including IEEE Pioneer Award in Nanotechnology, IEEE Photonics Society Engineering Achievement Award, OSA Nick Holonyak Jr Award, IUMRS Somiya Award, UNESCO medal for his contributions to the development of nanoscience and nanotechnologies and Lyle medal from Australian Academy of Science for his contributions to Physics. He has received Australia’s highest civilian honor, AC, Companion of the Order of Australia, for his contributions to physics and engineering, in particular nanotechnology.

Page- 46 GSELOP2021 Global Summit and Expo on Laser, Optics and Photonics August 23-25, 2021 | Paris, France A. Fuerbach A. Fuerbach, S. Rehman, L. Xu, G. Bharathan, S. Gross, T. Fernandez Department of Physics and Astronomy, Macquarie University, NSW 2109, Sydney, Australia Mid-Infrared Fibre Laser Technology Abstract We report on our research into the development of compact, robust and field-deployable laser systems in the mid-infrared spectral region. This specific part of the electromagnetic spectrum has long attracted much scientific and technological interest due to the fact that virtually all molecules have their rotational-vibrational absorption lines in this range. For this reason, the mid-infrared is often referred to as the “molecular fingerprint” region. Owing to the high-impact applications that result from the strong molecule-photon interaction, such as trace molecular detection for airport security screening and non-invasive breath analysis, mid-IR photonics has become one of the hottest topics in modern optics research. While virtually all current mid-infrared laser sources heavily rely on bulk- optical components and are consequently complex and sensitive systems that are restricted to be used in a vibration- temperature and humidity-controlled laboratory environment, our research aims at developing all integrated hybrid fibre/chip sources with high brightness.

Page- 47 GSELOP2021 Global Summit and Expo on Laser, Optics and Photonics August 23-25, 2021 | Paris, France Andrey A. Sukhorukov1 1ARC Centre of Excellence for Transformative Meta-Optical Systems (TMOS), Research School of Physics, The Australian National University, Canberra, ACT 2601, Australia *[email protected]

Quantum Photon Statemanipulation with Metasurfaces

Abstract Highly-transparentnanostructured dielectric metasurfaces have emerged as an important class of modern photonic elements. Recently, such metasurfaces were introduced to quantum photonics, opening a pathway for ultra-compact and robust manipulation and measurement of quantum light. Manipulation of multi-photon states, especially in the commonly-used polarization degree of freedom, is an active research topic associated with a variety of practical applications including quantum communications and simulations.

We present the advances on the realisation of tailored transformations of polarization states of classical and quantum light based on scattering and interference from specially engineered dielectric nano- resonators arranged in meta-gratings. We overview the latest theoretical and experimental results demonstrating the fundamentals aspects and potential applications of such ultra-thin metasurfaces. These include optimal monitoring of deviations from a selected polarization, a transformation of any input two-photon quantum polarization-entangled state to an arbitrary target state [1], and ghost discrimination between a set of objects with different polarization characteristics [2]. We anticipate that such capabilities can enable a new class of ultra-compact and ultra-sensitive flat meta-optical devices for a broad range of applications including advanced sensing, imaging, and metrology in both classical and quantum photonics. This presentation is based on results of collaborations driven by researchers who co-authored Refs. [1,2].

Keywords quantum optics, metasurface, polarization entanglement, ghost imaging

References [1] S. Lung, K. Wang, K. Zangeneh Kamali, J. Zhang, M. Rahmani, D. N. Neshev, A. A. Sukhorukov, “Complex-birefringent dielectric metasurfaces for arbitrary polarization-pair transformations,” ACS Photonics 7, 3015–3022 (2020). [2] A. Vega, K. Wang, S. Lung, D. E. Jones, M. Brodsky, T. Pertsch, F. Setzpfandt, and A. A. Sukhorukov, “Discerning Polarization Objects using Non-local Measurements with Metasurfaces,” In Conference on Lasers and Electro-Optics, FM1C.7 (OSA, 2020).

Biography Andrey Sukhorukov is a Professor at the Research School of Physics,Australian National University. He leads a research groupon nonlinear and quantum photonics with an overarching aim to addressthe key challenges in science and emerging technologies, spanning fromimaging and communications to precision optical measurements. Hisresearch targets the fundamental aspects of miniaturization of opticalelements down to micro- and nano-scale while achieving advancedfunctionalities beyond Page- 48 GSELOP2021 Global Summit and Expo on Laser, Optics and Photonics August 23-25, 2021 | Paris, France the capabilities of traditional optics. Inparticular, he works on the development of new concepts for tailoringlight-matter interactions in nano-structured materials for generation,manipulation, and detection of light down to few-photon levels in theregime of quantum optics. In 2015, he was elected a Fellow of theOptical Society (OSA).

Page- 49 GSELOP2021 Global Summit and Expo on Laser, Optics and Photonics August 23-25, 2021 | Paris, France

Kazuhiro Ohkawa Computer, Electrical and Mathematical Sciences and Engineering (CEMSE) Division, King Abdullah University of Science and Technology (KAUST), Thuwal, 23955-6900, Saudi Arabia E-mail: [email protected]

InGaN-based Red LEDs Grown by Micro-Flow Channel MOVPE Abstract Micro-LED displays are promising tools for the coming AR and VR usages and others. InGaN-based red micro-LEDs will be one of the keys to solving the cost issue in the production of the micro-LED displays since RGB micro-LEDs will be fabricated on the same substrate. We are developing InGaN- based red LEDs and their micro-LEDs based on our original technologies [1-8]. Our target wavelength of the red LEDs is over 630 nm to meet the recommendation 2020 standard for 4K-televisions (TVs) and ultra-high-definition TVs.

We have grown InGaN-based red LED structures by micro-flow-channel metalorganic vapor-phase epitaxy (MOVPE) because our original micro-flow channel MOVPE method can grow high-quality and high-In- content (>20%) InGaN [1, 2]. The InGaN active region was pseudomorphic due to the strain compensation introducing AlN and AlGaN as parts of the barriers of InGaN [3]. The hybrid structure enhances red emission [4]. Finally, the thick GaN under-layer can release compressive strain, resulting in high-quality and higher-In-content InGaN QWs [5].

Based on those technologies, we have fabricated the standard red LEDs with peak wavelengths over 630 nm [5, 6]. Its temperature dependence of light output is stable. The characteristics temperatures of our InGaN- and InGaP-based red LEDs were 399 K and 304 K, respectively [7]. The peak wavelength shift of our red LED was as good as 0.066 nm/K that is less than half of that of the InGaP-based one [7]. Figure 2 shows the demonstration of RGB micro-LEDs at KAUST [8]. More details will be presented at the conference.

Fig. 1 An InGaN-based red LED.

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Fig. 2 SEM and optical microscope photos of RGB micro-LEDs.

Reference [1] K. Ohkawa, T. Watanabe, M. Sakamoto, A. Hirako, et al., J. Cryst. Growth 343, 13 (2012). [2] K. Ohkawa, F.Ichinohe, T.Watanabe, K.Nakamura, D. Iida, J. Cryst. Growth 512, 69 (2019). [3] D.Iida, S.Lu,S.Hirahara,K.Niwa,S.Kamiyama,K.Ohkawa, J.Cryst. Growth 448, 105 (2016). [4] D. Iida, K. Niwa, S. Kamiyama, and K. Ohkawa, Appl. Phys. Express 9, 111003 (2016). [5] D. Iida, Z. Zhuang, P. Kirilenko, M. Velazquez-Rizo, M. Najmi, K. Ohkawa, Appl. Phys. Lett. 116, 162101 (2020). [6] D. Iida, Z. Zhuang, P. Kirilenko, M.Velazquez-Rizo, K. Ohkawa, Appl. Phys. Express 13, 031001 (2020). [7] Z. Zhuang, D. Iida, and K. Ohkawa, Appl. Phys. Lett. 116, 173501 (2020). [8] Z. Zhuang, D. Iida, and K. Ohkawa, Opt. Lett. 46, 1912 (2021).

Page- 51 GSELOP2021 Global Summit and Expo on Laser, Optics and Photonics August 23-25, 2021 | Paris, France Irina V. Kabakova* School of Mathematical and Physical Sciences, University of Technology Sydney, Ultimo 2007, NSW, Australia *[email protected]

Brillouin Imaging for Applications in Bioengineering and Tissue Regeneration

Abstract Brillouin microscopy (BM) is an emerging field that holds the potential to enable unparalleled mechanical mapping of cells, tissues and organs across three dimensions with submicron resolution [1]. It is rapidly gaining traction in biology and biomedical science communities due to its non-contact and label–free nature, offering clear advantages over existing methods of measuring mechanical properties on microscopic scale such as atomic force microscopy indentation, optical tweezers and rheology [2].

BM is based on the physics of Brillouin light scattering (BLS) in which light waves interact with high frequency (GHz) acoustic phonons, thermally excited vibrations within a material. As phonons are density perturbations that move at the speed of sound V, such an interaction results in a Doppler shift of the scattered light frequency by precisely the phonon frequency Ω

Ω=2nV/λ, (1) where n is the material refractive index and λ is the light wavelength. The sound speed, in turn, can be related to the material’s storage modulus M=ρV2 provided the material density ρ is known or can be estimated. The storage modulus has a meaning of inverse compressibility and serves as a measure of material’s elastic response at GHz frequencies. The lifetime of acoustic phonons on the other hand, carries information about the mechanical losses within the sample and for biologically relevant materials tells about material local viscosity. Thus, Brillouin imaging is capable of retrieving both local compressibility and viscosity in a single measurement without application of external forces or labels, both of which could change the properties or completely destroy the sample.

In this talk, I will present on the two applications of Brillouin imaging for 3D bioprinting and construction of artificial tissue models for studying spinal cord regeneration [3]. Both applications require precise knowledge and control over local micromechanical properties of fabricated tissue constructs and can greatly benefit from insights delivered by Brillouin imaging, including 3D micromechanical mapping and monitoring of the sample’s physical and structural properties over time.

Keywords Brillouin light scattering, confocal microscopy, bioprinting, tissue engineering

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References [1] Scarcelli, G. and S.H. Yun, Confocal Brillouin microscopy for three-dimensional mechanical imaging. Nature Photonics 2(1): p. 39-43, 2008. [2] Poon, C., et al., Brillouin imaging for studies of micromechanics in biology and biomedicine: from current state-of-the-art to future clinical translation. Journal of Physics: Photoncis 3(1), 012002, 2020. [3] Mahmoodi, H., et. al. Mechanical Mapping of bioprinted hydrogel models by Brillouin microscopy, Bioprinting, e00151, 2021.

Biography Dr Irina Kabakova is a Senior Lecturer and Brillouin Imaging Group Leader with the University of Technology Sydney. Her lab is developing new label-free spectroscopic and microscopic methods to characterize micro-mechanical properties of the range of materials, including biological materials, cells and tissues. Previously she was awarded Imperial College Research Fellowship where she spent 2 years developing fibre-integrated Brillouin imaging systems for remote sensing and endoscopy. Her area of expertise is integrated photonics, nonlinear optics and the physics of inelastic Brillouin scattering. She is currently teaching multiple courses in Medical Imaging and Medical Devices.

Page- 53 GSELOP2021 Global Summit and Expo on Laser, Optics and Photonics August 23-25, 2021 | Paris, France A. Vallés1,* A. Vallés1,*, S. Ohno2, T. Omatsu1, and K. Miyamoto1

1ARC Centre of Excellence for Transformative Meta-Optical Systems (TMOS), Research School of Physics, The Australian National University, Canberra, ACT 2601, Australia *[email protected]

On-Demand High-Resolution Single-Pixel Camera

Abstract Single-pixel imaging (SPI) is an imaging technique for reconstructing compressive images that employs a series of spatially resolved patterns to mask the object of interest while measuring the overall transmitted signal with a bucket detector [1], which lacks spatial resolution.

We present a simple terahertz SPI system to realize high pixel resolution 2D imaging in the entire terahertz frequency region (3-13 THz), using a high-sensitivity single-point THz detector and a novel pixel digitization technique. Thus, allowing an increase of pixel resolution on-demand [2]. We define the pixel resolution as the number of pixels representing a given imaging area; hence, an increase in pixel resolution enables us to distinguish smaller details in an image.

We show in the THz imaging results of Fig. 1 how the image spatial details can be substantially improved by increasing the pixel resolution of the random masks, from the spinning disk schematically shown in (a), thanks to the subpixel digitization technique. Figures 1(d) and (e) show the reconstructed images when illuminating the object (transmission intensity profile given in (b)) with 13 THz radiation and considering 32  32 and 320  320 pixel digital masks, as the examples given in the insets, respectively (considering an imaging area is of 32  32 mm2 in this case). Even higher pixel resolution image reconstruction is given in Fig. 1(f) to show the full potential of this SPI system, considering a smaller imaging area (12  12 mm2) but subdividing each physical pixel by 100  100, obtaining a final pixel resolution of 1200  1200.

Figure 1. Experimental results. (a) Metallic ring, (b) intensity profiles of the lambda-shaped object and its experimental SPI reconstruction using 13 THz radiation when considering the (d) 32  32 and (e) 320  320 pixel, and (f) considering a smaller imaging area but higher pixel resolution 1200  1200. Red horizontal lines in show cross section for profiles plotted in (c). Digitization examples of the imaging area from (a) are given in the insets. Page- 54 GSELOP2021 Global Summit and Expo on Laser, Optics and Photonics August 23-25, 2021 | Paris, France

Keywords Single pixel camera, subpixel digitization, terahertz imaging, 2D spectroscopy

References [1] M. P. Edgar, G. M. Gibson, and M. J. Padgett, Nat. Photonics 13, 13 (2019). [2] A. Vallés, et al., Opt. Express 28, 28868 (2020).

Biography Adam Vallés received his BSc in telecom engineering from the Polytechnic University of Catalonia (UPC) in 2011, and his MSc and PhD in photonics from the Institute of Photonic Sciences (ICFO) in 2012 and 2017, respectively. He was then awarded a Claude Leon Foundation postdoctoral fellowship to work in the Structured Light Lab from the University of the Witwatersrand, South Africa. He also worked as Assistant Professor at Chiba University, Japan, devising novel imaging techniques for the terahertz region. After 4 years of postdoctoral experience supervising students and leading international projects in collaboration with Heriot- Watt, Naples, Tohoku and Harvard universities, he joined the Optoelectronics group in ICFO where he is currently working as a Research Fellow. His research interests are mainly focused on high-dimensional quantum communication and quantum imaging.

Page- 55 GSELOP2021 Global Summit and Expo on Laser, Optics and Photonics August 23-25, 2021 | Paris, France T.Omatsu1,2* 1Graduate School of Engineering, Chiba University, Japan. 2Molecular Chirality Research Center, Chiba University, Japan. *[email protected]

Structured Light Twists Liquids Abstract Since Allen et.al. theoretically proposed that structured light fields, such as optical vortex, possess orbital angular momentum (OAM), associated with their helical wavefronts with an on-axis phase singularity. To date, we and our coworkers have discovered an entirely novel fundamental physical phenomenon, in which the OAM of light enables us to twist the irradiated materials, including metals, semiconductors, and polymers, to form helical structures on a nano/micron scale with the aid of spin angular momentum (SAM), associated with a helical electric field of circularly polarized light. Going beyond these light induced nano/micron scale helical structures, we here report on that structured light fields act as a trigger to ‘twist’ even liquid-phase materials, such as cure rein, high viscosity liquid film, and colloidal suspensions to form macroscale structures. Such new ‘twist’ of materials associated with interaction between light fields with OAM and matters will further lead to entirely novel fundamental materials sciences and advanced technologies and open the door towards printed photonics and chiral crystallization. Keywords structured light, optical vortex, orbital angular momentum, nanofabrication, printed photonics

References [1] M. Padgett, Opt. Express, 25, 11265-11274, (2017). [2] T. Omatsu, K. Miyamoto, K. Toyoda, R. Morita, Y.Arita, K. Dholakia, Adv. Opt. Mater., 7, 1801672, (2019). [3] R. Nakamura, H. Kawaguchi, M. Iwata, A. Kaneko, R.Nagura, S. Kawano, K. Toyoda, K. Miyamoto, T. Omatsu, Opt.Express, 27, 38019-38027, (2019). [4] M. Sakamoto, N.Uemura, R. Saito, H.Shimobayashi, Y. Yoshida, T. Mino, T. Omatsu,Angew. Chem. Int. Ed. (in press). Biography Professor Omatsu received his Ph.D. degree in applied physics from the University of Tokyo, in 1992, and he was appointed as a Professor in Chiba University, in 2007. He has been pioneering versatile optical vortex sources and nano/micro-structures fabrication based on optical vortex illumination. He is currently serving as a JSAP Director and an Editor-in-Chief, OSA Continuum, OSA publishing. He was elected as OSA Fellow, SPIE Fellow and JSAP Fellow.

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W. Yashiro1,2 1International Center for Synchrotron Radiation Innovation Smart (SRIS), Tohoku University Katahira 2-1-1, Aoba-ku, Sendai 980-8577, Japan. 2Institute of Multidisciplinary Research for Advanced Materials (IMRAM), Tohoku University, Katahira 2-1-1, Aoba-ku, Sendai 980-8577, Japan. *[email protected]

Synchrotron X-ray Tomography with Millisecond-Order Temporal Resolution Abstract Demand for visualizing internal structures with a high spatio-temporal resolution has been increasing in wide fields of life and materials sciences. Because there is generally a tradeoff between temporal and spatial resolutions, the improvement in sensitivity and the use of a high-flux X-ray beam are required for high temporal resolution without sacrificing spatial resolution. We successfully realized millisecond-order synchrotron X-ray tomography for a rotating sample [1]. The use of a white synchrotron X-ray beam from a bending magnet of SPring-8, Japan, enabled us to achieve 4D X-ray tomography with a spatio-temporal resolution of 5 μm and 10 ms [2]. However, high-speed sample rotation makes it difficult to precisely control the environment around the sample. In addition, 4D tomography of liquids and living animals is impossible because of the centrifugal force arising from the high-speed rotation. Realizing high-speed X-ray tomography without sample rotation is desired to solve these problems. Recently, we developed a novel multi-beam X-ray optical system for high-speed X-ray tomography without sample rotation [3]. We showed a proof of concept that the system makes it possible to realize tomographic reconstruction even with an exposure time of 1 ms. Keywords X-rays, Imaging, Tomography, Millisecond, Synchrotron Radiation

References [1] W. Yashiro et al., Appl. Phys. Exp., 10, 052501 (2017); W. Yashiro et al., Jpn. J. Appl. Phys., 56, 112503 (2017); W. Yashiro et al., Appl. Phys. Exp., 11, 122501 (2018). [2] R. Mashita, et al., J. Synchrotron Rad., 28, 322-326 (2021). [3] W. Voegeli et al., Optica, 7, 515 (2020).

Page- 57 GSELOP2021 Global Summit and Expo on Laser, Optics and Photonics August 23-25, 2021 | Paris, France

Biography Wataru Yashiro is a professor of International Center for Synchrotron Radiation Innovation Smart (SRIS), Tohoku University from 2021. He received phD degree in 2000 from the University of Tokyo, Japan. He was a research associate of Japan Society for JSPS, AIST, NIMS, and GSFS, the University of Tokyo, Japan. In 2005, he became an assistant professor of GSFS, the University of Tokyo, and moved to Tohoku University in 2012 to become an associate professor. Yashiro is a specialist of X-ray optics (X-ray imaging, dynamical X-ray diffraction, and X-ray surface crystallography). He received 5 remarkable awards, including The Optics and Quantum Electronics Achievement Awar d (Takuma Award) (2021). He is the leader of a project of CREST funded by JST from 2017 and is developing a new frontier of X-ray tomography.

Page- 58 GSELOP2021 Global Summit and Expo on Laser, Optics and Photonics August 23-25, 2021 | Paris, France H. W. Zan1* M. Deb1, O. Soppera2,3, and H. W. Zan1* 1Department of Photonics, College of Electrical and Computer Engineering, National Chiao Tung University, 1001 Ta Hsueh Rd. Hsinchu, Taiwan. 2Université de Haute-Alsace, CNRS, IS2M UMR 7361, F-68100 Mulhouse, France 3Université de Strasbourg, France *[email protected]

NIR Laser Annealed Metal Oxide Semiconductor for Flexible Gas Sensors Abstract In this work, we developed low power near-infrared (NIR) laser annealing technique to treat the

solution-processed sol-gel SnO2 semiconductor thin film. Good conductivity and the sensing response

to hydrogen sulfide (H2S) gas can be realized. Unlike conventional annealing temperature higher than 300 °C, the thermal imager measurement confirms that the substrate temperature can be kept

at lower than 50 °C under the NIR laser irradiation. After forming an SnO2 resistor with a channel

length as 200 µm, the current-voltage characteristics and the H2S sensing response under various NIR laser power (20W/cm2, 40W/cm2) and irradiation time (60 sec) were investigated. A ultra-flexible

H2S gas sensor on food plastic wrap was also successfully demonstrate to real time detect H2S gas ranged from 100 to 1000 part-per billion (ppb). We surprisingly found that the low power (20W/ cm2) condition delivered better gas sensing response than the mid power (40W/cm2) condition. After analyzing the surface bonding condition using the X-ray photoelectron spectroscopy (XPS), we investigated the gas sensing response as a function of the metal-oxide bonding ratio. Noted that in our previous report [1], we demonstrated NIR-laser treated IZO to serve as gas sensor. Here we further reduce the laser power to realize gas sensor on food plastic wrap and extend into SnO2 material. A more detailed material analysis is also done to investigate the underlaying mechanism. Keywords metal-oxide semiconductor, NIR laser, gas sensor, flexible sensor References [1] P.Y. Chang, C.F. Lin, S. El Khoury Rouphael, T.H. Huang, C.M. Wu, D. Berling, P.H. Yeh, C.J. Lu, H.F. Meng, H.W. Zan, and O. Soppera, ACS app. Mater. & interfaces, 12(22), 24984-24991, (2020) Biography Hsiao-Wen Zan received her Ph.D. degree from the Institute of Electronics, National ChiaoTung University, Hsinchu, Taiwan, in 2003. She is currently a professor in Department of Photonics,National Yang Ming Chiao Tung University, Taiwan. Her research interests focus on semiconductordevices and their applications, particularly on solution-processed organic or metal oxidesemiconductor devices with nanostructures. She also devotes in developing bio/chemicalsensors by collaborating Page- 59 with medical doctors. GSELOP2021 Global Summit and Expo on Laser, Optics and Photonics August 23-25, 2021 | Paris, France S. Xie1 S. Xie1, X. Yi2, X. Jin2, B. Liang3, L.W. Lim2, D. L. Huffaker1, C. H. Tan2 and J. P. R. David2 1School of Physics and Astronomy, Cardiff University, Cardiff, CF24 3AA, UK 2Department of Electronic and Electrical Engineering, University of Sheffield, Sheffield, S1 3JD, UK. 3California NanoSystems Institute, University of California-Los Angeles, Los Angeles, CA 90095, USA Current address: SIMIC Advanced Micro Semiconductors Co. Ltd. 888 2nd West Huanhu Street, Pudong, Shanghai , 201306, China. Current address: Electrical Engineering Department, University of Texas at Arlington, Arlington, TX 76019, USA

High Speed And High Sensitivity

Alas0.56Sb0.44 Avalanche Photodiodes

Abstract Avalanche photodiodes (APDs) are widely used in optical communication systems due to the high sensitivity provided by its internal gain. However traditional APDs using InP and InAlAs as multiplication layers fail to provide satisfactory sensitivity at higher bandwidths due to their broadly similar impact ionization coefficient ratios, especially at high electric fields. AlAs0.56Sb0.44 is a promising avalanche material which can be grown lattice-matched to an InP substrate and therefore use InGaAs as the absorption region. We have demonstrated that the α and β (the electron and hole ionisation coefficients respectively), in this material are very dissimilar, much more than even in silicon.This property leads to AlAs0.56Sb0.44 having the lowest excess noise performance of any InP based material system. Full bandwidth and sensitivity analysis shows that utilising a 600 nm thick InGaAs absorber and a 600 nm AlAs0.56Sb0.44 multiplication region in a Separate Absorption and Multiplication APD (SAM-APD) configuration can operate at 1550 nm and 25 GB s-1 with a sensitivity of -25.7 dBm, about 3 dBm better than the best results reported to date. Recently measurements suggest thatAlAsSb shows a significantly lower breakdown voltage variation with temperature than equivalent thickness InAlAs and InP structures. This weaker temperature dependence of AlAsSb reduces the complexity control of the external bias circuit as well as temperature controller, which maintains the sensitivity of APD-receiver module.

Page- 60 GSELOP2021 Global Summit and Expo on Laser, Optics and Photonics August 23-25, 2021 | Paris, France Yijie Shena Optoelectronics Research Centre, University of Southampton, Southampton SO17 1BJ, UK

Structured Light Towards Multiple Degrees Of Freedom And Higher Dimensions Abstract

Structured light, with ability to arbitrarily tailor degrees of freedom (DoFs) of light, amplitude, phase, wavelength, etc, has recently attracted great promotion for fundamental science and advanced applications. In addition to the basic DoFs in light, there are also some complex DoFs emerged as the combination of common DoFs, such as angular momentum, vector singularity, ray-wave trajectory, spatiotemporal vortex, etc., showing their power in optical manipulation. In this talk, I summarize the advanced methods of manipulating tunable DoFs and creating new DoFs in structured light, as a roadmap guiding the development of multi-dimensional structured light. We also discuss the significance of the multi-DoF control in both fundamental physics and novel applications. Keywords Structured light, singularity, angular momentum

Page- 61 GSELOP2021 Global Summit and Expo on Laser, Optics and Photonics August 23-25, 2021 | Paris, France Daniel Ramos Instituto de Micro y Nanotecnología (IMN-CNM, CSIC), 8, Isaac Newton, 28760, Tres Cantos, Madrid (Spain) *Email [email protected]

Nanomechanical Plasmon Spectroscopy: Optomechanics as a New Plasmonic Transducer Abstract We have developed a high throughput spectrometric technique addressing single biological entity (bacteria) resolution. This novel technique will be used to develop a novel imaging technique based on mechanical frequency shift of a nanomechanical resonator to generate a mechanical image of single particles and bacteria. The physical principle behind this technique is the modulation of the light absorption by the particle, which is translated into a thermo-mechanical effect on the nanomechanical resonator. This idea was recently demonstrated by using plasmonic gold particles of 100 nm in diameter [1] and to mechanically image viruses and bacteria cells (in press) of 700 nm in diameter. We will show not only the optomechanical coupling that emerges in the cavity formed by a plasmonic nanoparticle onto a free-standing silicon nitride membrane, but also the thermomechanical coupling by using dielectric particles. The optical absorption depends on the scatterer material; therefore, it is possible to unambiguously discern in between different dielectric particles and bacteria cells of the same size by simply analyzing the mechanical frequency shift while shinning with a laser [2]. The optical absorption can also be tuned by playing around with the optical resonances of a photonic crystal, which allows to actively tune the mechanical resonance frequency.

a b

100 nm

Figure. a. Schematic depiction of the system used for the mechanical imaging of gold nanoparticles of 100 nm in diameter and the experimental mechanical image of the whole membrane. b. Membranes used for the mechanical image of Staphylococcus epidermidis (SEM image taken at CSIC) and the first experimental mechanical image.

Page- 62 GSELOP2021 Global Summit and Expo on Laser, Optics and Photonics August 23-25, 2021 | Paris, France

Keywords LSPR, Optomechanics, Optical Absorption, nanomechanical transduction References [1] D. Ramos, O. Malvar, Z. J. Davis, J. Tamayo, and M. Calleja “Nanomechanical Plasmon Spectroscopy of Single Gold Nanoparticles”, Nano Letters18, 7165-7170 (2018)]. [2] D. Ramos et al, Accepted in ACS Omega 2021. Biography Daniel Ramos holds a Distinguished Researcher position at the Institute of Micro and Nanotechnology (IMN-CSIC). He obtained his PhD degree in Physics from the Universidad Complutense de Madrid (2009) carrying out his research at the Bionanomechanics Lab at Microelectronics Institute of Madrid (IMM-CNM-CSIC). After that period, he was a post-doctoral researcher at Nanodevices Lab, Yale University (2009-2010), and the Laboratory for Nanoscale Optics, Harvard University (2011-2013) financed by a Marie Skłodowska-Curie grant from the European Union. His research activities are mainly focused on the interplay in between phonons and photons in optomechanics with special attention to the energy exchange from electromagnetic field and nanomechanical resonators with applications in novel sensing schemes

Page- 63 GSELOP2021 Global Summit and Expo on Laser, Optics and Photonics August 23-25, 2021 | Paris, France O. Neufeld1* O. Neufeld1*, Z. Nourbakhsh1, N. Tancogne-Dejean1, and A. Rubio1,2

1Max Planck Institute for the Structure and Dynamics of Matter, Hamburg, 22761, Germany. 2Center for Computational Quantum Physics (CCQ), The Flatiron Institute, New York, NY, 10010, USA. *[email protected]

Theoretical Description of High Harmonic Generation in Liquids

Abstract High harmonic generation (HHG) is an extremely nonlinear optical process that takes place in all phases of matter. In gases, where it was first discovered, it has been extensively studied and is very well-understood. In solids research is ongoing, but a consensus is forming for the dominant HHG mechanisms. In liquids however, no theoretical model exits yet, and approaches developed for gases and solids are generally inapplicable. Here there are many open questions that remain unanswered such as cutoff scaling laws, the dominant HHG mechanisms, and more. Advancement on this front, which may lead to novel light sources and ultrafast spectroscopies, is hindered by the lack of theoretical frameworks for liquids interacting with strong fields, as well as the lack of simplified models for the dynamics. We present an ab-initio cluster-based approach for describing the interaction of liquids and intense light. We employ it to study liquid- HHG in water, ammonia, and methane, and compare the characteristic response of polar and non-polar liquids. We also analyze the various fundamental behaviors of liquid HHG, such as the temporal and spectral structure of the harmonic spectra, and the cutoff scaling laws. We then formulate a simplified semi-classical picture for electron dynamics in the liquid that includes ultrafast scattering processes, and show that it provides results in agreement with the ab-initio calculations. Through the semi-classical picture for liquid-HHG, we show the importance of scattering on the electron light-driven dynamics in liquids.

Keywords High harmonic generation, Strong-field Physics.

Biography

Dr. Neufeld received dual BSc degrees, summa cum laude, in Materials Science and Physics from the Technion – Israel Institute of Technology in 2014. Following this, in 2016 he received his MSc degree in Energy Engineering, summa cum laude, where his thesis explored theoretical approaches for improving the performance of photovoltaic devices under the supervision of Prof. Maytal Toroker in the Technion. In 2020 he completed his PhD in Physics under the supervision of Prof. Oren Cohen, where he investigated helical high harmonic generation in atoms and molecules and techniques for ultrafast spectroscopy of chirality. He is currently a postdoctoral Humboldt research fellow in the group of Prof. Angel Rubio in Hamburg, where he is working on strong-field physics in condensed matter systems.

Page- 64 GSELOP2021 Global Summit and Expo on Laser, Optics and Photonics August 23-25, 2021 | Paris, France

Satishchandra B. Ogale Research Institute for Sustainable Energy (RISE), The Chatterjee Group’s Centers for Research and Education in Science and Technology (TCG-CREST), Salt Lake, Kolkata-700091, India And Indian Institute for Science Education and Research (IISER), Pune-411008, India

Exciting Diversity of Structures and Properties of Molecularly Engineered Hybrid Perovskite Materials Systems

Abstract Hybrid perovskites have been at the focus of intense scientific attention, excitement, and scrutiny,ever since they displayed extremely impressive solar cell efficiencies in conceptually different next generation cell architectures. Having realized the optoelectronic strengths and facile property tunability of these materials, the research community is now looking to explore further opportunities of novel applications of this class of materials in diverse domains. Towards this end, strategic and intelligent molecular engineering offers significant advantages and opportunities. In this talk I will try to capture this excitement by taking some examples from own research and putting the same into perspective by highlighting some other related key studies. This will include examples of molecular ion doping, use of functional molecules to tune and control dimensionality and use select molecular interventions to dramatically enhance some of the application worthy properties. I will also discuss some interesting applications of the new hybrid molecular systems.

References: Ogale and Coworkers, Angew. Chem. (https://doi.org/10.1002/anie.202105918), J. Phys. D: Appl. Phys (Invited Topical Review) 54, 133002 (2021), Adv. Opt. Mater. 6, 1800751 (2018), APL Materials 6, 086107 (2018), APL Materials 6, 114204 (2018), ChemSusChem, 10, 3722-3739 (2017), Advanced Materials Interfaces, 4, 1700562 (2017), J. Phys. Chem. Letts., 7 (22), 4757 (2016), ChemComm, 50, 9741-9744 (2014)

Page- 65 GSELOP2021 Global Summit and Expo on Laser, Optics and Photonics August 23-25, 2021 | Paris, France M. J. Huttunen* M. J. Huttunen*, T. Stolt,A. Vesala and J. Kelavuori Photonics Laboratory, Physics Unit, Tampere University, FI-33014 Tampere, Finland. *[email protected]

Towards Efficient and All-optically Controlled Nonlinear Metamaterials Abstract Nonlinear optical phenomena are important in many photonic applications ranging from all-optical switches and generation of ultrashort pulses to frequency comb-based metrology. Often the fabricated photonic components should be as small as possible, resulting in a demand for nano- or small-scale nonlinear components. This demand for miniaturized nonlinear photonic components is difficult to answer by using conventional nonlinear materials motivating the search for alternatives. Nonlinear plasmonic metasurface cavities have recently emerged as a potential platform to enable nanoscale nonlinear optics [1]. Despite steady progress, the so far achieved conversion efficiencies have not yet rivalled conventional materials. Here, we present our recent work to develop more efficient nonlinear metamaterials, focusing on plasmonic metasurfaces that support collective responses known as surface lattice resonances [2,3]. These resonances are associated with very narrow spectral features, showing potential to dramatically boost nonlinear processes via resonant interactions. Here, we will first discuss of our recent demonstration of a plasmonic metasurface operating at the telecommunications C band exhibiting a record-high quality factor close to 2400, demonstrating an order-of-magnitude improvement compared to existing metasurface cavities [4]. Then, we will show our recent results demonstrating how such high-Q factor resonances could be tuned by changing the ambient temperature of the system. Finally, we will show how conversion efficiencies of nonlinear metasurfaces could be further enhanced by fabricating phase-matched stacked metasurfaces [5]. Keywords Nonlinear metasurfaces, multiply-resonant, second-harmonic generation, phasematching

References [1] M. Kauranen et al., Nat. Photonics 6, 737 – 748, (2012). [2] V. G. Kravets et al., Chem. Rev., 118, 5912–5951 (2018). [3] M. J. Huttunen, P. Rasekh, R. W. Boyd and K. Dolgaleva, Phys Rev. A, 97, 053817, (2018). [4] M. S. Bin-Alam, et al., Nature Commun.,12, 974, (2021). [5] T. Stolt, et al., Phys. Rev. Lett.,126, 033901, (2021).

Page- 66 GSELOP2021 Global Summit and Expo on Laser, Optics and Photonics August 23-25, 2021 | Paris, France Shuji Nakamura Materials and ECE Departments Solid State Lighting and Energy Electronics Center University of California Santa Barbara Santa Barbara, CA 93106 USA Email: [email protected]/ Phone: (805)-893-5552

III-Nitride BasedMicro-LEDs

Abstract As next generation displays, micron-sized light-emitting diode (µLED) displays have been researched intensively with advantages of higher wall-plug efficiency and wider color gamut compared to conventional liquid crystal displays (LCDs) and organic LED (OLED) displays. Currently, mini LED displays with a chip size of more than 100 µm are commercially available in spite of huge costs caused by a large chip size. For blue and green LEDs, InGaN-based LEDs are used, while for red, AlInGaP-based LEDs are currently used. In order to reduce the cost of µLED displays and to open a market for the application of small displays such as smart phones and AR/VR displays, each chip size has to be reduced to a micron size. When the size of µLEDs becomes small (especially smaller than 40 µm), the EQE decreases dramatically. This decrease is due to surface recombination and the sidewall damage of the mesa from the plasma-assisted dry etching, which contribute to increased Shockley-Read-Hall non-radiative recombination at small dimensions [1].Potassium hydroxide (KOH) has been used to improve the electrical performance of GaN based devices by removing the plasma-damaged material on the device side walls [1] However, there are several issues with the conventional µLEDs, such as color mixing, color purity, emission directionality, and thermal and color stability.Those problems of µLEDs could be addressed by using single mode emission InGaN-based blue, green and red microcavity light-emitting diodes (MC-LEDs). These MC-LEDs have advantages of thermal stability and spectral purity since the spectral width and shape are determined by the overlap of the InGaN quantum well (QW) emission and the cavity mode. In addition, the emission of MC-LEDs is more directional than conventional LEDs.These advantages suggest MC-LEDs could be the best fit for display applications.

Ultra-short cavity MC-LED with a cavity length of 200 nm which had a peak external quantum efficiency (EQE) of 0.8%was demonstrated. Recently, by removing the dry etching damage of the

sidewall using phosphoric acid (H3PO4) treatment, we could increase the peak EQE up to 7.3% [2], which is almost the same as that of a conventional c-plane µLED. The demonstration of MC-LEDs with a high EQE of 7.3% and a single mode emission should pave the way for the application of display and others.

Also, edge emitting LD and vertical cavity surface emitting laser (VCSEL) would be described.

Page- 67 GSELOP2021 Global Summit and Expo on Laser, Optics and Photonics August 23-25, 2021 | Paris, France

References [1] M.S. Wong et al., ECS J. Solid State Sci. Technol. 9, 015012 (2020). [2] J. Back et al., Appl. Phys. Lett. 118, 031102 (2021).

Page- 68 GSELOP2021 Global Summit and Expo on Laser, Optics and Photonics August 23-25, 2021 | Paris, France A. Theodosiou1 A. Theodosiou1, and K. Kalli2 1Lumoscribe LTD, Paphos 8310, Cyprus. 2Cyprus University of Technology, Limassol 3036, Cyprus. *[email protected]

Towards All-Fiber Mode Locked Mid-IR Fiber Lasers Abstract Ultrafast lasers are critical tools for various important applications. Among the different pulse laser designs, passively mode-locked fibre lasers are particularly attractive sources of high- quality ultrashort pulses. The tilted fibre Bragg gratings (TFBGs) can be used as all-in-fibre polarising elements in such arrangements for fibre lasers with wavelength emission up to 2.2 μm where the silica fibres are operational. At the same time, higher wavelengths as the mid-infrared region (mid-IR) attracted interest for various uses such as spectroscopy, gas sensing, military applications. However, the absence of bright light sources in this part of the spectrum, the limited fibre components and, as a result, the bulk polarisers typically employed negate the natural benefit of the all-fibre configurations and minimises the scientific and technological interest. In this work, we will present our recent progress on developing high polarising and low loss TFBGs, inscribed in a ZBLAN passive fibre for potential use as a polarising element for a mode- locked laser in 3.5μm

Keywords Femtosecond laser inscriptions, Tilted fibre Bragg gratings, Mode locked laser, Pulse lasers, fibre lasers Biography Dr. Antreas Theodosiou is the director and owner of the Lumoscribe LTD. He is finished his PhD in the Cyprus University of Technology with specialization in photonics and optical sensors. His research includes inscription and development of optical sensors using femtosecond laser systems, waveguides, Bragg gratings, Mach-Zehnders, Fabry-Perot cavities, in polymer, silica, and other novel optical materials, and various applications using optical fibre sensors. In addition, has experience working with demodulation algorithms for complicated Bragg gratings spectrums, and fibre lasers. He has published more than 45 journal papers in high impact factor papers, more than 50 papers in international conferences, and 7 invited presentations. In addition, he has active collaboration with various universities and research centres and participated in various national and international research projects. This work was co-funded by the European Regional Development Fund and the Republic of Cyprus through the Research and Innovation Foundation (Project:POST-DOC/0718(sp. ext.)/0003).

Page- 69 GSELOP2021 Global Summit and Expo on Laser, Optics and Photonics August 23-25, 2021 | Paris, France N. Vermeulen Brussels Photonics (B-PHOT), Vrije Universiteit Brussel, Department of Applied Physics and Photonics (IR-TONA), Pleinlaan 2, 1050 Brussel, Belgium. [email protected]

Nonlinear-Optical Refractive Response of Graphene and Graphene-Covered Waveguides Abstract Over the past decade there has been extensive theoretical and experimental research on the nonlinear-optical refractive response of graphene. Nonlinearities with different orders of magnitudes and different signs have been reported, making it a major challenge to fully understand graphene’s nonlinear-optical behavior. In this talk, I will present the theoretical and experimental work performed by our group to solve this issue [1, 2]. In our experiments, we investigated nonlinear spectral broadening of laser pulses in waveguides covered with monolayer graphene and we observed that graphene-covered silicon nitride waveguides can produce exponentially growing spectral broadening at sub-Watt pulse powers. Through modelling, we found that this extra-ordinary behavior relies on a new phenomenon called ‘saturable photo-excited carrier refraction (SPCR)’ taking place in the graphene layer [2]. In a next step, we developed a formalism that links the efficiency of the SPCR process with graphene’s fundamental material properties [3]. This formalism, which is based on the so-called population recipe, allows explaining the various nonlinearity values that have been reported for graphene over the past several years by different research groups and also provides a powerful tool to predict graphene’s nonlinear-optical behavior in future experiments.

Keywords graphene, waveguides, nonlinear optics, spectral broadening, carrier refraction References [1] N. Vermeulen, D. Castelló-Lurbe, J. L. Cheng, I. Pasternak, A. Krajewska, T. Ciuk, W. Strupinski, H. Thienpont, J. Van Erps, Phys. Rev. Applied 6, 044006 (2016). [2] N. Vermeulen, D. Castelló-Lurbe, M. Khoder, I. Pasternak, A. Krajewska, T. Ciuk, W. Strupinski, J. L. Cheng, H. Thienpont, J. Van Erps, Nat. Comm. 9, 2675 (2018). [3] D. Castelló-Lurbe, H. Thienpont, N. Vermeulen, Laser Photonics Rev. 19402 (2020). Acknowledgements ERC-FP7/2007-2013 grant 336940, FWO grants G005420N and G0F6218N (EOS-convention 30467715), VUB-OZR

Page- 70 GSELOP2021 Global Summit and Expo on Laser, Optics and Photonics August 23-25, 2021 | Paris, France

Biography Nathalie Vermeulen holds a Tenure Track professor position in the Brussels Photonics group (B-PHOT) at Vrije Universiteit Brussel, Belgium. In 2013 she obtained a Starting Grant from the European Research Council (ERC) for her NEXCENTRIC research project on graphene-enhanced nonlinear photonic chips, and between 2013 and 2017 she also coordinated the European Future and Emerging Technologies (FET) project GRAPHENICS.

Page- 71 GSELOP2021 Global Summit and Expo on Laser, Optics and Photonics August 23-25, 2021 | Paris, France Ori Katz Department of Applied Physics, Faculty of Natural Sciences

The Hebrew University of Jerusalem, 9190401 Jerusalem, ISRAEL

Author e-mail address: [email protected]

Lensless Endoscopy Through Flexible Multi-Core Fibers Abstract

Scattering of light in complex samples such as biological tissue renders most samples opaque to conventional optical imaging techniques, a problem of great practical importance. However, although random, scattering is a deterministic process, and it can be undone, controlled, and even exploited by carefully shaping the input wavefront, forming the basis for the emerging field of optical wavefront-shaping [1,2], and opening the path to imaging through visually opaque samples [3] and to the control of scattered ultrashort pulses [4].

I will present some of our recent efforts in utilizing these new insights for the development of novel endoscopic techniques that utilize extremely small footprint bare multi-core fibers (MCFs) for 3D microscopic imaging in real-time, overcoming the intra-core phase-distortions of MCFs by a set of techniques ranging from wavefront-shaping, through real-time holography, to computational speckle- correlation based approaches

References

[1] Z. Merali, “Optics: Super vision”, Nature 518, 158 (2015).

[2] A.P. Mosk et al., "Controlling waves in space and time for imaging and focusing in complex media", Nature Photonics 6, 283 (2012).

[3] O. Katz et al., "Looking around corners and through thin turbid layers in real time with scattered incoherent light", Nature Photonics 6, 549 (2012).

[4] O. Katz et al., "Focusing and compression of ultrashort pulses through scattering media", Nature Photonics 5, 372 (2011).

Page- 72 GSELOP2021 Global Summit and Expo on Laser, Optics and Photonics August 23-25, 2021 | Paris, France N. Granchi1*

N. Granchi1*, R. Spalding2, M. Lodde3,M. Petruzzella3, F. W. Otten3, A. Fiore3, F. Intonti1 ,R. Sapienza4, M. Florescu2 and M. Gurioli1 1Department of Physics and Astronomy and LENS, University of Florence, Sesto Fiorentino (FI), Italy 2Advanced Technology Institute and Department of Physics, University of Surrey, Surrey, UK 3Department of Applied Physics and Institute for Photonic Integration, Eindhoven University of Technology, Eindhoven, NL 4The Blackett Laboratory, Department of Physics, Imperial College London, UK *[email protected]

Sub-Wavelength Light Localization In Hyperuniform Disordered Systems Abstract Located in-between random structures and perfectly ordered photonic crystals, there is a special class of disordered heterostructures called hyperuniform disordered (HuD) photonic structures. These materials, due to the presence of a photonic bandgap, combine the advantages of disordered systems and ordered systems. In this work we present the first near-field optical investigation in the near IR of a HuD photonic system. The investigated system is a HuD dielectric structure on two GaAs parallel membranes with air circular holes following a specific pattern; the design is derived from a stealth hyperuniform point pattern with a stealthiness parameter χ = 0.5. We show that these materials, due to the presence of a photonic bandgap, combine the advantages of disordered systems and ordered systems. Like random structures they exhibit a large plethora of photonic modes with high spatial density. However, while their statistical properties are robust against fabrication induced disorder, they are deterministic materials in the sense that it is possible, by means of theoretical calculations, to predict where light localization will take place experimentally, both spatially and spectrally. Moreover, the Q factors of the optical cavities arising from light localization that were experimentally detected are one order of magnitude larger than in the case of disordered systems, and the photoluminescence enhancement factor is doubled.We address the physics of the detected resonances, going from Anderson-like resonances, to more delocalized regimes, by describing important statistical properties. This achievements might open fascinating routes for addressing basic physics and applications of an innovative class of materials, proposable as an alternative to both ordered and disordered systems. Keywords Hyperuniform, Near-field, Photonic Bandgap, Disorder

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References [1] M. Florescu, S. Torquato and P.J. Steinhardt, Proc. Natl. Acad. Sci. U.S.A. 106, 20658–20663 (2009). [2] N. Muller, J. Haberko, C. Marichy, and F. Scheffold, Adv. Opt. Mater., 2, 115-119 (2014).

Page- 74 GSELOP2021 Global Summit and Expo on Laser, Optics and Photonics August 23-25, 2021 | Paris, France P.C. Ku1,* 1Dept. of Electrical Engineering and Computer Science, University of Michigan, Ann Arbor, MI 48109, USA. *[email protected]

Strain Engineering in Gallium Nitride Optoelectronics Abstract Controlling strain is an important consideration for the design of modern electronic and optoelectronic devices. Excessive strain leads to material defects and lowers device performance. An adequate amount of strain, on the other hand, can profoundly modify optoelectronic properties, resulting in new device capabilities. In this talk, I will review local strain engineering in gallium nitride optoelectronics and how this leads to new functionalities that are otherwise difficult to attain. Demonstrations of potential applications in microdisplays, quantum information processing, robotics, and spectroscopic sensing will be discussed. Keywords single photon source, light-emitting diode, spectrometer, tactile sensor Biography P.C. Ku received his BS from the National Taiwan University and PhD from the University of California at Berkeley, both in Electrical Engineering. He was awarded the Ross Tucker Memorial Award in 2004 as a result of his PhD research. He was with Intel before joining the University of Michigan where he is currently a professor of electrical engineering and computer science. His research interests are primarily in the area of optoelectronic devices and their applications. In 2010, he cofounded Arborlight that was dedicated to solid-state lighting system design and application. He received the DARPA Young Faculty Award in 2010.

Page- 75 GSELOP2021 Global Summit and Expo on Laser, Optics and Photonics August 23-25, 2021 | Paris, France E.Sooudi1* E.Sooudi1*, H.Asghar2, 3, and J. G.McInerney4 1Infinera Corporation, 6373 San Ignacio Avenue, San Jose, CA 9511, USA. 2National Center for Physics, Quaid-i-Azam University Campus, Islamabad 45320, Pakistan 3Department of Physics, School of Science, Sialkot Campus, University of Management and Technology (UMT), Sialkot 51310, Pakistan. 4Department of Physics and Tyndall National Institute, University College Cork, Western Road, T12 YN60 Cork, Ireland. *[email protected]

Optical Methods for Improving the Performance of Quantum-Dash Semiconductor Mode-Locked Lasers and Applications Abstract InP based quantum-dash mode-locked lasers are compact and robust laser sources emitting at 1.55 µm with low threshold current density, broad optical spectrum, low noise performance and few pico-second pulse generation.Further optimization of timing jitter, optical and RF linewidth, and time- bandwidth product can be achieved using several external optical control methods. In this paper, we review various external optical control techniques to improve the performance of these lasers. Techniques such as single tone CW and dual-tone coherentoptical injection, optical feedback, and combination (all-optical) of CW optical injection and filtered or unfiltered optical feedback can be used to improve some or all critical optical/RF characteristics of these lasers. In addition, applications of injection-locked mode-locked lasers with anchored repetition-rate to a central RF clock as a multi-pump source in multi-channel phase-sensitive amplifiers are demonstrated as a key enabling technology in future all optical multi-channel optical regenerators. Keywords injection-locking, mode-locked lasers, optical feedback, opticalfrequency combs References [1] E. Sooudi. et al, IEEE J. Quantum Electron., 48,(10), 1327-1338, (2012). [2] H. Asghar, W. Wei, P. Kumar, E. Sooudi, and J. McInerney, Opt. Express,26, 4581-4592, (2018).

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Biography Ehsan Sooudi received his Ph.D. degree in physics from University College Cork, Cork, Ireland in 2013.Since 2012, he has been at the Centre for Advanced Photonics and Processing Analysis and Irish Photonic Integration Centre at Tyndall National Institute, Cork Ireland, working on the research and development of novel photonic devices and systems. In 2018, he joined Alcon Laboratories in Ireland working on qualification of optical metrology systems for intraocular lenses. He is currently with Infinera Corporation, Sunnyvale, CA, USA working on test development of next generation InP based photonic integrated circuits for telecom/datacom applications. Dr. Sooudi is a semifinalist for the Corning Outstanding Student Paper Award at the Optical Fiber Communications Conference (OFC), 2012. He has authored and co-authored 30+ scientific papers and is regular reviewer for IEEE & OSA journals.

Page- 77 GSELOP2021 Global Summit and Expo on Laser, Optics and Photonics August 23-25, 2021 | Paris, France T.Yatsui1 1Toyohashi University of Technology,1-1 Hibarigaoka, Tenpaku-cho, Toyohashi, Aichi 441-8580, Japan *[email protected]

New Photochemical Reactions and the Applications Using a Non-Uniform Optical Near-Field Abstract In this presentation, I will give a talk regarding recent progress of the new chemical reactions and the applications based on a non-uniform optical near-field [1]. In through the theoretical study,we found new photochemical reactions which does not satisfy the dipole approximation [2]. We applied the properties of the optical near-field to various applications including the near-field etching [3,4], highly efficient CO2 reduction [5,6], and the highly efficient Siphoto-detector [6,7]. This work was partially supported by JSPS KAKENHI (Nos.18H01470,20H0219, 20H05091,20K21118) and JST A-STEP. Keywords non-uniform optical near-field, ultra-flat surface, CO2 reduction References [1] T. Yatsui, M. Yamaguchi and K. Nobusada, Progress in Quantum Electronics 55, 166 (2017) (review article). [2] M. Noda, K. Iida, M. Yamaguchi, T. Yatsui, and K. Nobusada, Phys. Rev. Appl., 11, 044053 (2019). [3] T. Yatsui, T. Tsuboi, M. Yamaguchi, K. Nobusada, S. Tojo, F. Stehlin, O. Soppera, and D. Bloch, Light: Science & Applications 5, e16054 (2016). [4] F. Brandenburg, R. Nagumo, K. Saichi, K. Tahara, T. Iwasaki, M. Hatano, F. Jelezko, R. Igarashi, and T. Yatsui, Scientific Reports 8, 15847 (2018). [5] T. Yatsui, Y. Nakahira, Y. Nakamura, T. Morimoto, Y. Kato, M. Yamamoto, T. Yoshida, K. Iida, and K. Nobusada, Nanotech. 30, 34LT02 (2019). [6] T. Yatsui, Y. Nakamura, Y. Suzuki, T. Morimoto, Y. Kato, M. Yamamoto, T. Yoshida, W.Kurashige, N. Shimizu, Y.Negishi, K. Iida, and K. Nobusada, ournal of Nanophotonics, 4, 046011 (2020). [7] T. Yatsui, S. Okada, T. Takemori, T. Sato, K. Saichi, T. Ogamoto, S. Chiashi, S. Maruyama, M. Noda, K. Yabana, K. Iida, and K. Nobusada, Communications Physics 2, 62 (2019). [8] T. Yatsui, Opto-Electronic Advances, 2, 190023 (2019) (review article).

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Biography Takashi Yatsui was born in Tokyo, Japan, on January 21, 1972. He received his B.E. degree from Keio University, Tokyo, Japan in 1995 and M.E. and D.E. degrees from Tokyo Institute of Technology, Tokyo, Japan in 1997 and 2000, respectively. From 2000 to 2008, he was a Researcher at the Japan Science and Technology Agency, Tokyo. In 2020, he joined Toyohashi University of Technology as a Professor. His current research interests include nanofabrication using optical near-field and its application to nanophotonics. Dr. Yatsui received numerous awards including the Gottfried Wagener Prize in 2010, Osaka University Kondo Prize in 2012, Erlangen Innovation Award Optical Technologies in 2012, Fuji Sankei Business-i Award in 2013, The Ichimura Prize in Science for Distinguished Achievement in 2016, Optical Engineering Awardin 2019, Nagai Award in 2021.

Page- 79 GSELOP2021 Global Summit and Expo on Laser, Optics and Photonics August 23-25, 2021 | Paris, France Federico Capasso John A. Paulson School of Engineering and Applied Sciences, Harvard University Cambridge, MA 02318, USA [email protected]

The Flat Optics Revolution: from Metalenses to Cameras

Abstract Metasurfaces have enabled the redesign of optics into thin and planar elements1-4. The planarity of flat optics will lead to the unification of semiconductor manufacturing and lens making, where the planar technology to manufacture chips will be adapted to make CMOS compatible metasurface based optical components, impacting technology and science. Advances in high performance metalenses, multifunctional meta optics and cameras will be presented along with the path to high- volume commercialization. Important trends in flat optics are: co-design of hardware and software for realizing new systems, such depth cameras with small computational burden, increased role of AI in photonics, such as free-form metaoptics by inverse design, pervasive impact on wearable displays (AR-VR) and the emergence of entirely new multifunctional components.

Reference 1. N. Yu and F. Capasso, "Flat optics with designer metasurfaces," Nat. Mater. 13, 139 (2014) 2. M. Khorasaninejad and F. Capasso “Metalenses: Versatile multifunctional photonic components” Science 358, 8100 (2017) 3. W. T. Chen, A. Y. Zhu, and F. Capasso, “Flat optics with dispersion-engineered metasurfaces.” Nature Reviews Materials, 5, 604 (2020) 4. Wei Ting Chen and F. Capasso “Will flat optics appear in everyday life anytime soon?” Applied Physics Letters, 118, 100503 (2021)

Page- 80 GSELOP2021 Global Summit and Expo on Laser, Optics and Photonics August 23-25, 2021 | Paris, France Manijeh. Razeghi Center for Quantum Devices, Northwestern University, Evanston, IL 60208-0893, USA *phone: (847) 491-7251, fax: (847) 467-1817, email: [email protected]

Breaking Spectral and Performance Barriers For Detectors and Fpas ; The Power Of Sb- Type II Superlattice Materials Innovation

Abstract The SW, MW, LWIR and VLWIR photodetectors and imagers are highly desirable for different applications such as earth science and astronomy, remote sensing, optical communication, and thermal and medical imaging. The Sb based gap -engineered Type-II superlattices (T2SLs) has drawn a lot of attention since it was introduced in 1970 by Leo Ezaki et al, , for infrared detection as a system of multi-interacting quantum wells. T2SL material system has experienced incredible improvements in design, gap and atomic engineering, high qualitymaterials, device structure designs and device fabrication process, which elevated the performances of T2SL-based photodetectors to a comparable or superior level to the state-of-the- art material systems for infrared detection such as Mercury Cadmium Telluride (MCT). As a pioneer in the field, center for quantum devices (CQD) has been involved in growth, design, characterization, and introduction of Sb based T2SL material system for infrared photodetection and imaging from deep UV to THZ . This talk will present the power of Sb based materials innovation for breaking spectral and performance barriers for photodetectors and Imagers from deep UV to THZ. at CQD/NU.

Page- 81 GSELOP2021 Global Summit and Expo on Laser, Optics and Photonics August 23-25, 2021 | Paris, France Zhigang Chen 1The MOE Key Laboratory of Weak-Light Nonlinear Photonics, TEDA Applied Physics Institute and School of Physics, Nankai University, Tianjin 300457, China 2Department of Physics and Astronomy, San Francisco State University, San Francisco, California 94132, USA [email protected]

Nonlinear Control of Photonic Topological States Abstract Topological photonics has attracted widespread research attention in the past decade, in which paradigmatic approaches have beenproposed to realize topological insulators and topological lasers. In this talk, I will report onour recent work on demonstration of nonlinear control of topologicalstates in reconfigurable photonic lattices. In the 1D case, we focus onthe topological states in the celebrated Su-Schrieffer-Heegerlattices, includingweakly nonlinear topological gap solitons, nonlinearity-induced coupling to topological edge states, andnonlinear tuning of PT symmetry and non-Hermitian topological states. In the 2D case, we present an example of nonlinear control of higher-order topological bound states in continuum. Our work may prove relevant and inspiring for exploration of fundamental phenomena in nonlinear topological systems beyond photonics.

Page- 82 GSELOP2021 Global Summit and Expo on Laser, Optics and Photonics August 23-25, 2021 | Paris, France Zubin Jacob Purdue University, USA www.electrodynamics.org

New Applications of Quantum Magnetometry: Photonic Spin Density and Atomistic Topological Electrodynamics Abstract Nitrogen vacancy (NV) centers in diamond have emerged as promising room temperature quantum magnetometers for probing condensed matter phenomena ranging from spin liquids, 2D magnetic materials ,and magnons to hydrodynamic flow of current. Here, we propose and demonstrate that the nitrogen-vacancy center in diamond can be used as a quantum magnetometer for detecting the photonic spin density. We exploit a single spin qubit on an atomic force microscope tip to probe the spinning field of an incident Gaussian light beam. The spinning field of light induces an effective static magnetic field in the single spin qubit probe. We perform room-temperature sensing using Bloch sphere operations driven by a microwave field (XY8 protocol). This nanoscale quantum magnetometer can measure the local polarization of light in ultra-subwavelength volumes. We also put forth a rigorous theory of the experimentally measured phase change using the NV center Hamiltonian and perturbation theory involving only virtual photon transitions. The direct detection of the photonic spin density at the nanoscale using NV centers in diamond opens interesting quantum metrological avenues for studying exotic phases of photons, nanoscale properties of structured light as well as future on-chip applications in spin quantum electrodynamics (sQED) We also propose to identify and search for atomistic topological electrodynamic phases of matter using quantum magnetometry. Over the past three decades, graphene has become the prototypical platform for discovering unique phasesof topological matter. Both the Chern C∈Z and quantum spin Hall υ∈Z2 insulators were first predicted in graphene, which led to a veritable explosion of research in topological materials. We introduce a new topological classification of two-dimensional matter – the optical N-phases N∈Z. This topological quantum number is connected to polarization transport and captured solely by the spatiotemporal dispersion of the susceptibilitytensorχ. We verify N= 2 in graphene with the underlying physical mechanism being repulsive Hall viscosity. An experimental probe, evanescent magneto-optic Kerr effect (e-MOKE) spectroscopy, is proposed to demonstrate this repulsion. To conclude, we develop topological circulators by exploiting gapless edge plasmons that are immune to back-scattering and navigate sharp defects with impunity. Our work indicates the optical N-invariant is a universal property that captures topological electrodynamic physics beyond graphene.

Page- 83 GSELOP2021 Global Summit and Expo on Laser, Optics and Photonics August 23-25, 2021 | Paris, France S. Avramov-Zamurovic1* S. Avramov-Zamurovic1*J. Esposito1 and C. Nelson2 1​Weapons, Robotics and Control Engineering Department, 2​Electrical and Computer Engineering Department, United States Naval Academy, 597 McNair Road, Annapolis, MD 21402 *[email protected]

Underwater Communication System Using Laser Light Carrying Orbital Angular Momentum Abstract The focus of our research is to develop a high data rate communication system operating in extremely degrading environments. We design an alphabet using laser beams that carry orbital angular momentum. Gaussian-Laguerre beams are a class of orthogonal beams that allow us to superimpose the N basis beams and create an alphabet with 2N symbols by utilizing binary switching. The transmission rate is limited by the rate with which we can switch the basis beams, and the alphabet expands the bandwidth N fold.To diversify the range of basis beams we select to generate the transmitted messages using Spatial Light Modulator (Fig.1). The beams are propagated through underwater optical turbulence. The index of refraction structure constant is experimentally measured to be~10-8 m-2/3, signifying extremely strong optical turbulence (about six orders of magnitude higher than any published work). The receiver consists of a camera capturing the light intensity and the machine learning algorithm classifying the symbols in the alphabet. We achieve classification rates higher than 93% when classifying 47 symbols in the extremely strong underwater optical turbulence (Fig.2). Machine learning algorithm uses custom developed CNN that is capable of classifying symbols at the 10kHz rate using a computer with modest capabilities. These results are supporting our design of an effective high data rate communication system.

Fig. 1 Transmitter: Generating alphabet symbols using basis beams.

Page- 84 GSELOP2021 Global Summit and Expo on Laser, Optics and Photonics August 23-25, 2021 | Paris, France

Fig. 2Receiver: a sample of 47 alphabet symbols received after propagation through the strong underwater turbulence.

Keywords underwater, communication system, machine learning Biography Svetlana Avramov-Zamurovic is a Professor at Weapons Robotics and Controls Department at United States Naval Academy, Annapolis, Maryland. She teaches midshipman the fundamentals of laser propagation in maritime environment and systems control. She earned PhD in Electrical Engineering at the University of Maryland in 1994. Her thesis Measuring AC voltage ratio using inductive voltage dividers describes her developing instrumentation for two NASA shuttle missions. Presently, she is interested in measuring laser light intensity fluctuations influenced by optical turbulence in real maritime environmental conditions. She experiments with beam shaping with a goal to maximize delivered laser energy on target in complex media. Professor Avramov-Zamurovic, with her colleagues, performed various experiments at the grounds of the Academy and in laboratory settings, successfully verifying theoretical predictions on performance of the laser beams propagating in maritime environment.She is a guest scientist at the National Institute of Standards and Technology, and Naval Research Lab.

Page- 85 GSELOP2021 Global Summit and Expo on Laser, Optics and Photonics August 23-25, 2021 | Paris, France Yuhwa Lo University of California San Diego, USA

Single Photon Detection with Disordered Material as the Gain Medium Abstract Single photon detectors find important applications in quantum communications, sensing, and LiDARs for autonomous driving and AR/VR. Here we describe a new physical mechanism, cycling excitation process (CEP), which can amplify photocurrent efficiently and quietly to detect single photons. Unlike impact ionization processin APDs where momentum conservation (k-selection rule) has to be satisfied, the cycling excitation process (CEP) involves excitation of localized states or bound excitons, thus relaxing the k-selection ruleto achievehigh carrier multiplication efficiency. In addition, CEP effect is a phonon-mediated amplification process in which electron-phonon interactions play the roles of built-in negative feedback to suppress gain fluctuations, thus giving rise to low excess noise below the prediction of the McIntyre’s model. Interestingly, the CEP effect is found to be strongest in disordered materials such as amorphous silicon (a-Si), which is easy and low cost to fabricate and can be compatible with CMOS and display processes. In this talk, we will discuss the physics of CEP mechanism and device characteristics including high gain under low bias voltage, high gain-bandwidth product, ultralow excess noise, single photon sensitivity with high Geiger mode gain and self-quenching and self-recovering characteristics without external quenching circuit.

Page- 86 GSELOP2021 Global Summit and Expo on Laser, Optics and Photonics August 23-25, 2021 | Paris, France Wei Wu1* Boxiang Song1,2, Pan Hu1, Yunxiang Wang1, Zerui Liu1, Deming Meng1, Hao Yang, Fanxin Liu3, and Wei Wu1* 1Ming Hsieh Department of Electrical and Computer Engineering, University of Southern California, Los Angeles, CA USA 90089 2Huazhong University of Science and Technology, Wuhan, Hubei, PR China 3Department of Applied Physics, Zhejiang University of Technology, Hangzhou, PR China *E-mail: [email protected]

Plasmonic Structures and Applications Fabricated Using Collapsible Nano-Fingers

Abstract Nano-gap structure has attracted great scientific interests. For example, plasmonic nanostructures with nano-gapsconcentrate light to a small volume, which can lead to many potential applications. While it is theoretically predicted that the optimal plasmonic hot spot is a gap of less than 1 nanometer between two metallic particles, there is still no manufacturing technology to reliably fabricate it with high-precision and controllability at practical cost.In this work, we invented a technology to fabricate large-area gapped plasmonic structures deterministically with atomic precision, high throughput and high reliability at low cost. The technology is based on collapsible nano-fingers fabricated using nanoimprint lithography(NIL)[1] and ALD.Several applications have been realized based on this technology. For example, we studied the quantum phenomena in the gap plasmon[2]. Moreover, we also demonstrated label-free single molecule sensing with surface-enhanced Raman spectroscope (SERS)[4], studied the plasmon-enhanced molecular fluorescence[3], and achieved plasmonic- enhance photocatalysis using devices fabricated by this technology. Keywords Plasmonics, nanofabrication, nanoimprint, SERS, nanophotonics, plasmon-enhanced fluorescence References [1] S. Y. Chou, P. R. Krauss, P. J. Renstrom, Appl. Phys. Lett. 1995, 67, 3114. [2] B. Song, Y. Yao, R. E. Groenewald, Y. Wang, H. Liu, Y. Wang, Y. Li, F. Liu, S. B. Cronin, A. M. Schwartzberg, S. Cabrini, S. Haas, W. Wu, Acs Nano 2017, 11, 5836. [3] B. Song, Z. Jiang, Z. Liu, Y. Wang, F. Liu, S. B. Cronin, H. Yang, D. Meng, B. Chen, P. Hu, A. M. Schwartzberg, S. Cabrini, S. Haas, W. Wu, Acs Nano 2020. [4] F. Liu, B. Song, G. Su, O. Liang, P. Zhan, H. Wang, W. Wu, Y. Xie, Z. Wang, Small 2018, 14, 1801146.

Page- 87 GSELOP2021 Global Summit and Expo on Laser, Optics and Photonics August 23-25, 2021 | Paris, France

Biography Dr. Wei Wu is an associate Professor at the Ming Hsieh Department of Electrical Engineering, University of Southern California. He graduated from Peking University with a BS in Physics in 1996 and received a Ph.D. in Electrical Engineering from Princeton University in 2003.His work includes nanoimprint lithography and applications in nano-electronics, nano-photonics, plasmonics, chemical sensing and nano-electrochemical cells.He coauthored 111 peer-reviewed scientific journal papers with 10346 citations, 2 book chapters and more than 100 conference presentations. He has 118 granted US. His H-index is 49. He is a co-editor of Applied Physics A and an associate editor of IEEE Transactions on Nanotechnology. He was also an IEEE Nanotechnology Council 2015 and 2016 distinguished lecturer, and a recipient of USC Stevens Center for Innovation Commercialization Award 2020. He is currently the chair of nanofabrication technical committee (TC3), IEEE Nanotechnology Council.

Page- 88 GSELOP2021 Global Summit and Expo on Laser, Optics and Photonics August 23-25, 2021 | Paris, France Zhenguo Lu1* Zhenguo Lu1*, Khan Zeb1,2, Guocheng Liu1, Jiaren Liu1, Youxin Mao1, Philip J. Poole1, Ruoshi Xu1,3, Yu Huang1,3, Pedro Barrios1, James Pan1,4, John Weber1, Xiupu Zhang2, Jianping Yao3, and Ke Wu5, 1Advanced Electronics and Photonics Research Centre, National Research Council, Ottawa, ON, Canada 2iPhotonics Labs, Department of Electrical and Computer Engineering, Concordia University, Montreal, QC, Canada 3School of Electrical Engineering and Computer Science, University of Ottawa, Ottawa, ON, Canada 4Department of Electrical Engineering, University of British Columbia, Vancouver, BC, Canada 5Department of Electrical Engineering, Ecole Polytechnique Montreal, Montreal, QC, Canada *Corresponding Author E-mail: [email protected]

Quantum-Dot Coherent Comb Lasers For 5G and Beyond Wireless Networks Abstract We have designed, grown, fabricated and investigated several InAs/InP quantum-dot (QD) coherent comb lasers (QDCCLs) around 1550 nm with the frequency spacing from 10 GHz to 1000 GHz [1]. Those QD CCLs have very low RIN, ultra-narrow optical linewidth, small timing jitters, compact size, low power consumption and the ability for hybrid integration with silicon substrates. We have modulated the selected wavelength channels of the QD CCL by using data formats 16QAM and 32QAM with the symbol rate of up to 10 Gbaud, and have used ultra-fast photodetectors to generate mmW signals of the QD CCL [2]. The performance of the QD CCL is investigated in a photonic aided radio-over-fiber (RoF) system through 25-km standard single-mode fiber (SSMF) and a real time mmW RoF wireless communication system with a data bandwidth of up to 50 Gbit/s (10-Gbaud × 32QAM) and EVM of less than 8% has been demonstrated. Keywords Quantum dot lasers; mmW generation and transmission; 5G and beyond wireless networks; Reference [1].Zhenguo Lu, et al. IEEE J. Lightwave Tech., (Invited Review Paper), 39(12), 3751-3760 (2021). [2]. Khan Zeb, Zhenguo Lu, et al., Optics Express, 29 (11), 16164-16174 (2021).

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Biography Dr. Zhenguo Lu is a Principal Research Officer, Team Lead of Photonics and Project Leader of National Challenge Program “HTSN” at Advanced Electronics and Photonics (AEP) Research Centre of National Research Council (NRC), Ottawa, Canada. He also serves as an Adjunct Professor at Department of Electrical & Computer Engineering of both University of Ottawa and Concordia University in Canada since 2006. Dr. Lu has joined NRC as a Research Officer in 1997. He is an expert in the field of photonics devices and their applications in optical coherent networks, data center networks, 5G & beyond wireless networks. He has published over 250 refereed journal and conference papers, and 8 US patents. He has given over 50 invited talks in the international conferences, universities and industry companies.

Page- 90 GSELOP2021 Global Summit and Expo on Laser, Optics and Photonics August 23-25, 2021 | Paris, France Mariama Rebello Sousa Dias1 A. Rehan1, R. Kent1,2, M. K. Kreider1, A. Bezerra3, and Mariama Rebello Sousa Dias1 1Department of Physics, University of Richmond, Richmond VA, USA 2Department of Physics, Ohio State University, Columbus OH, USA 3Departamento de Fisica, Universidade Federal de Alfenas, Alfenas, Brazil

Improving The Performance of Photonic Devices by Engineering Alloys and Intermetallic

Abstract The use of nanostructures with varied chemical compositions is promising for improving the performance of photonic devices such as plasmonic assisted catalists, surface plasmon resonance (SPR) sensors, and solar cells. In order to determine the ideal composition for a particular application, we use a combination of traditional methods of material synthesis and characterization, and simulation and modeling methods to enabled the expansion of databases that cover the optical properties of known and hypothetical systems. In this work, we designed an artificial neural network trained to predict an Al-Au system's dielectric response. To confirm our prediction, we fabricated bimetallic films with different compositions and measured their optical response at different temperatures. We find that the accuracy of the ML is very high, and the time response is relatively short. Moreover, we show that all alloys outperform their pure counterparts in sensitivity, with Au0.85Al0.15 being the best candidate for replacing pure gold in SPR sensors.

Page- 91 GSELOP2021 Global Summit and Expo on Laser, Optics and Photonics August 23-25, 2021 | Paris, France L. Misoguti* * São Carlos Institute of Physics, University of São Paulo, PO Box 369, 13560-970 São Carlos, SP, Brazil.

Polarization-Resolved Measurements: New Tools to Discriminate the Origin of the Third-Order Nonlinear Refractive Signals Abstract Femtosecond laser pulses have many special characteristics which bring several advances in applied optics. In nonlinear optics, for instance, the broad bandwidth, high intensity and short pulse duration are explored by several ways to improve the understanding of nonlinear optical effects. Indeed, thanks to the tunable femtosecond laser pulses, it is possible to determine the nonlinear spectral response of several materials. Moreover, among the study of response time of ultrafast phenomena, we can use these pulses with appropriate laser polarization and different experimental methods to discriminate the origin of nonlinear effects [1,2]. As it is known, an effective nonlinear optical signal can arise from different origins such as nearly instantaneous bound-electronic, non- instantaneous nuclear contributions and thermal effects which need to be discriminated for better materials’ characterization point of view. In this context, in this presentation, I will present how the laser polarization can be explored to understand the third-order nonlinear refractive properties of materials. Keywords Z-scan, Nonlinear refraction, Nonlinear ellipse rotation, Kerr effect, Ultrafast laser

References [1] M. S. Melhado, T. G. B. de Souza, S. C. Zilio, E. C. Barbano, Opt. Express, 28, 3352 – 3360 (2020). [2] M. L. Miguez, T. G. B. de Souza, E. C. Barbano, S. C. Zilio, and L. Misoguti, Opt. Express 25, 3553 (2017)

Biography Lino Misoguti received his Ph.D degree in Material Science and Engineering in 1999 from USP at São Carlos working with nonlinear optical properties of new organic crystals. From 1999 to 2001 in his Postdoctoral position in the Center for Ultrafast Optical Science, University of Michigan and JILA, University of Colorado, he worked with ultrafast lasers. Currently he is Professor at the IFSC- USP, where his main research interest lies in ultrafast laser pulse applications for nonlinear optics, fundamental understanding of nonlinear effects, developing new methods for nonlinear optical measurements, etc. He is a member of the SBF, OSA (Senior Member) and IEEE.

Page- 92 GSELOP2021 Global Summit and Expo on Laser, Optics and Photonics August 23-25, 2021 | Paris, France Matt Kalinski Department of Chemistry and Biochemistry Utah State University, Logan UT 84322-0300 matt. [email protected]

Multi-Electron Trojan-Like Wavepackets on Synchronous Regular Polygon Trajectories in the Magnetic Field Abstract Some time ago we have discovered that placing the Langmuir trajectories [1] of the type one i.e those in the “Hoop Earrings” configuration in a combination of the symmetry augmented Circularly Polarized (C.P.) electromagnetic field and the magnetic field perpendicular to the planes of the both electron parallel circular motions results in classical stabilization of the resulting Langmuir trajectories which therefore can support the stable non-dispersing quantum Trojan Wave Packets [2]. We have also discovered that replacing the weak moving spin dipole electron magnetic field in so called Gryzinski model of atom [3] with the classically free falling electron avoiding the normal Coulomb collision with the nucleus by the uniform magnetic field leads to the regular polygon trajectories and the associated nondispersing Trojan wave packets on them when the Circularly Polarized (C.P.) field is added. Here we find the multi-electron nondispersing wavepackets in the joined combination of the external C.P. field and the perpendicular static magnetic field and the frequency tuned to the natural frequency of the closed periodic polygon orbits for N electrons. Unlike in the single electron case each of N electrons is synchronously hopping between the regular polygon vertices and stop at them to accelerate further while they interact with each other with the order of the polygon equal to that of the electrons. Numerical simulations using the split operator method for the 3D Hartree approximation as well as our recently developed Time Dependent Quantum Diffusion Monte Carlo Method are also provided.

References 1. I. Langmuir, “The Structure of the Helium atoms”, Phys. Rev. 17, 339 (1921). 2. M. Kalinski, L.Hansen, and D. Farrelly, “Nondispersive Two-Electron Wave Packets in a Helium Atom”, Phys. Rev. Lett. 95, 103001-103004 (2005). 3. M. Gryzinski, “Radially Oscillating Electrons - the Basis of the Classical Model of the Atom”, Phys. Rev. Lett. 53, 1059 (1965).

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Biography Matt Kalinski (born 1968) is US theoretical physicist who discovered Trojan wave packets, squeezed, coherent and intrinsically coordinate-entangled states of electrons in true atoms solving the long standing problem of interstellar rocket propulsion by extending the positron or positronium lifetime and control the arbitrary slowdown of the recombination process of antimatter in positronic rocket engine. Kalinski earned his PhD from the University of Rochester. The broad applications of his discov- ery of coherent non-dispersing electrons are important and not limited to photonic superconductivity, laser centrifugal isotope separation of Deuterium, detection of ultra-weak magnetic fields with Aharonov-Bohm effect and Berry’s phase, observa- tion of Unruh-Davies effect as well as the detection of gravitoelectromagnetic force and precise engineering of complex quantum dot systems.

Page- 94 GSELOP2021 Global Summit and Expo on Laser, Optics and Photonics August 23-25, 2021 | Paris, France E. R.Martins1* A.Martins1, B-H. V. Borges1, T. F. Krauss2, and E. R.Martins1* 1São Carlos School of Engineering Department of Electrical and Computer Engineering, University of São Paulo, 13566-590, Brazil. 2University of York, Department of Physics, York, YO105DD, UK *[email protected]

Metalenses with Arbitrarily Wide Field of View Abstract Metalenses are an emerging light-weight technology that offers unprecedented flexibility in shaping wavefronts with arbitrary phase profiles[1]. One remarkable feature of metalenses is their possibility of achieving arbitrarily wide field of view with a single layer. Such feature arises when a quadratic phase discontinuity is imposed on a wavefront [2, 3]. Interestingly, this functionality cannot be achieved with bulk optics [2], as the quadratic metalens essentially acts as a spherical bulk lens in the limit of infinite radius and infinite refractive index [2]. Here, we will discuss the physics and applications of metalenses with arbitrarily wide field of view, insightfully compare their optical features with diffraction limited metalenses, and show how polarization effects and straightforward pos-processing strategies can be used to improve the quality of images.

There is no fee for submission of an abstract, but the accepted abstract will appear in the conference program only if you pay the registration fee in full by the deadline.

Keywords metasurface, metalenses, imaging, field of view

References [1] H. Liang, A. Martins, B-H. V. Borges, J. Zhou, E. R. Martins, J. Li, T. F. Krauss, Optica, 6, 1461- 1470 (2019). [2] A. Martins, K. Li, J. Li, H. Liang, D. Conteduca, B-H. V. Borges, T. F. Krauss, E. R. Martins, ACS Photonics, 7, 2073-2079 (2020). [3] X. Luo, M. Pu, Y. Guo, X. Li, F. Zhang, X. Ma. Advanced Optical Materials474, 2001194 (2020)

Biography Dr. Emiliano R. Martins completed a degree in Electrical Engineering in 2005 (USP, Brazil). He holds a Msc in Electrical Engineering (USP, Brazil, 2008) and a Msc in Photonics (St. Andrews, UK, 2010). In 2014 he completed his PhD with a thesis entitled “Light Management in Optoelectronic Devices” (St. Andrews, UK). He is currently a professor at the University of São Paulo (USP, Brazil). His main research interests are in controlling light for applications in optoelectronics, biosensors and integrated optical systems. His research activities involve photonic crystals, metamaterials and metasurfaces, plasmonics, biophotonics, photovoltaics and thin-films.

Page- 95 GSELOP2021 Global Summit and Expo on Laser, Optics and Photonics August 23-25, 2021 | Paris, France S.Fathpour CREOL, The College of Optics and Photonics, University of Central Florida, USA. *[email protected]

Has Lithium Niobate Photonics Been Rejuvenated?

Abstract The excellent electrooptic and nonlinear-optical properties of lithium niobate have long established it as a prevailing photonic material for the long-haul telecom modulator and wavelength-converter markets. However, conventional lithium niobate optical waveguides are low index-contrast, and hence bulky compared to modern integrated platforms such as silicon photonics. The bulkiness impedes photonic circuit implementations and imposes high optical power requirements for nonlinear applications.

To address these shortcomings, thin-film lithium niobate wafers and high-contrast waveguides (with submicron cross-sectional dimensions) were developed for the first time at CREOL in 2013. Since then, we have demonstrated a plethora of ultracompact integrated photonic devices and circuits (waveguides, microring resonators, modulators, grating couplers, wavelength converters, entangled photon sources, etc.) with significantly superior performances than the conventional lithium niobate counterparts. More recently, commercial availability of the thin-film wafers has facilitated entering of several other research teams into this growing field. The overall efforts have rejuvenated lithium niobate for novel electrooptic and nonlinear- and quantum-optic applications and the material is considered among the top candidates for heterogeneous integrated photonics. That is when multiple materials are monolithically integrated on the same silicon chip, while each material is chosen for the functionalities that suits it best.

Progress in thin-film lithium niobate integrated photonics, its future directions, opportunities and challenges will be presented.

Keywords Heterogeneous integrated photonics, thin-film lithium niobate, electrooptic modulators, nonlinear optics

Biography Sasan Fathpour is a Professor at CREOL, The College of Optics and Photonics at the University of Central Florida. His current research interests include heterogeneous integrated photonics, nonlinear integrated optics, silicon photonics, and unconventional photonic platforms operating in the mid-wave- and near-infrared and visible wavelength ranges. He has received the US National Science Foundation (NSF) CAREER Award (2012) and the US Office of Naval Research (ONR) Young Investigator Program Award (2013). He is a co-author of over 180 publications, including 40 invited journal papers and conference presentations, 6 book chapters and 3 patents. He has co- edited the book Silicon Photonics for Telecommunications and Biomedicine, CRC Press (2012). He is the cofounder of Partow Technologies, LLC, and is a Fellow of OSA, a Senior Member of IEEE and SPIE and a Member of MRS.

Page- 96 GSELOP2021 Global Summit and Expo on Laser, Optics and Photonics August 23-25, 2021 | Paris, France Shin’ichiro Hayashi* Shin’ichiro Hayashi*and Norihiko Sekine National Institute of Information and Communications Technology (NICT), 4-2-1 Nukuikitamachi, Koganei, Tokyo, 184-8795, Japan. *[email protected]

Bidirectional Wavelength Conversion between Infrared and Terahertz-wave using Nonlinear Optics

Abstract Terahertz-wave region (frequency: 0.1–10THz (corresponding wavelength: 3– 0.03 mm)) are important not only in basic sciences, such as spectroscopy, electron acceleration, plasma measurement, and radio astronomy, but also in numerous industrial applications, such as in broadband wireless communication, highprecision radar, global environmental measurement, and non-destructive inspection, since they have higher directivity thanmicrowaves withlower frequency and higher transmittances in atmosphere and in soft materials than mid-infrared with higher frequency. Therefore, in the terahertz region, high-brightness and tunable sources, high-sensitivity and wideband detectors that could be widely used in these studies and applications are required. In this presentation, we demonstrate the generation of high-brightness terahertz-wave using parametric

wavelength down-conversion from infrared to terahertz-wave in a nonlinear MgO:LiNbO3 crystal[1]. We also demonstrate the detection of terahertz-wave using nonlinear up-conversion in the same process. We speculate that the high-brightness terahertz-wave and its coherent detection could be powerful tools not only for solving real world problems but also fundamental physics, such as real-time spectroscopic imaging, remote sensing, 3D-fabrication, and manipulation or alteration of atoms, molecules, chemical materials, proteins, cells, chemical reactions, and biological processes. We expect that these methods will open new fields.

Keywords Terahertz-wave, Nonlinear Optics, Wavelength conversion

References [1] S. Hayashi, K. Nawata, T. Taira, J. Shikata, K. Kawase, and H. Minamide, Sci. Rep., 4, 5045 (2014). Acknowledgement The authors would like to thank Prof. Kawase of Nagoya University, Dr. Nawata, Dr. Minamide, and Prof. Ito of RIKEN, Prof. Taira of IMS, Dr. Sakai of Hamamatsu Photonics, Prof. Shikata of Nihon University, Prof. Ohno of Tohoku University, Prof. Miyamoto of Chiba University, Dr. Urata of PHLUXi for useful discussions. This work was partially supported by JSPS KAKENHI Grant Number 18H01908, Tohoku University – NICT Matching. Biography Shin’ichiro Hayashi received the Ph.D. degree in physics from Meiji University, Japan, in 2004. From 2004, he was with RIKEN, Japan, as a Researcher. In 2016, he joined the NICT, as a Senior Researcher. His research interests include bright terahertz-wave generation and coherent detection using nonlinear optics, and their applications. Page- 97 GSELOP2021 Global Summit and Expo on Laser, Optics and Photonics August 23-25, 2021 | Paris, France David Burghoff1* 1Department of Electrical Engineering, University of Notre Dame, Notre Dame, IN 46656, USA *[email protected]

Frequency Comb Ptychoscopy Abstract The unique structure of frequency combs, light sources whose lines are perfectly evenly-spaced, allows for new avenues in the measurement of optical signals. By beating sources with the many lines of a comb, their spectra are recovered. Even so, these approaches are fundamentally limited to probing coherent sources, such as lasers. They are unable to measure most spectra that occur in nature. We will discuss frequency comb ptychoscopy[1], a technique that allows for the spectrum of any complex broadband source to be retrieved using a comb. In this approach, the spectrum is reconstructed by unfolding the simultaneous beating of a source with each comb line. We demonstrate this both theoretically and experimentally, at microwave frequencies. This approach can reconstruct the spectrum of nearly any complex source to high resolution, and the speed, resolution, and generality of this technique will allow chip-scale frequency combs to have an impact in a wide swath of new applications, such as remote sensing and passive spectral imaging.

Keywords frequency combs, spectroscopy, radiometry, quantum cascade lasers

References [1] D. J. Benirschke, N. Han, and D. Burghoff, “Frequency comb ptychoscopy,” Nat Commun, vol. 12, no. 1, p. 4244, Jul. 2021, doi: 10.1038/s41467-021-24471-4.

Biography David Burghoff is an Assistant Professor in the Department of Electrical Engineering at Notre Dame, having started in 2018. Prior to this he was a postdoctoral fellow and research scientist at the Massachusetts Institute of Technology, where he received his Ph.D. in Electrical Engineering. His research centers around frequency combs and nonlinear optics in quantum-engineered photonic systems, and his awards include the ONR Young Investigator Award, the NSF CAREER Award, the AFOSR Young Investigator Program Award, MIT’s Best Electrical Engineering Ph.D. Thesis Award, and the Intelligence Community Postdoctoral Fellowship. Page- 98 Poster Presentation GSELOP2021 Global Summit and Expo on Laser, Optics and Photonics August 23-25, 2021 | Paris, France A. Bucinskas1* A. Bucinskas1*, R. Durgaryan1, O. Bezvikonnyi1, D. Volyniuk1, J. V. Grazulevicius1, A. Tomkeviciene1

1Department of Polymer Chemistry and Technology, Kaunas University of Technology, Radvilenu St. 19, LT-50254, Kaunas, Lithuania;*[email protected]

New Hole Transporting Materials with Electron- Donating(Alkoxy- and N,N-Dialkylamine-) Substituents: Synthesis and Investigation Abstract Between the cathode and anode organic light emitting diodes (OLEDs) possess 3-6 additional layers based on electroactive semiconducting materials with unique function. For example, the main purpose of hole transporting layer in OLED structure is to ensure efficient migration of positive charges, electron-blocking from the emission layer towards anode and operational stability (lifetime of device). During the last decade, many research groups had been focusing their attention and huge resources in the search of emitters and host materials, while slightly ignoring the importance of hole transporting materials for OLEDs. Around 40-50% of published OLED structures are built using widely known commercially available hole transporting materials, such as, TCTA (tris(4-carbazoyl- 9-ylphenyl)amine), NPB (N,N′-Di(1-naphthyl)-N,N′-diphenyl-(1,1′-biphenyl)-4,4′-diamine), TAPC (4,4′-cyclohexylidenebis[N,N-bis(4-methyl phenyl) and m-MTDATA (4,4',4"-tris(N-3-methylphenyl-N- phenyl-amino) triphenylamine) [1,2], whereas, the stability of these compounds has long been called into question [3,4]. Therefore, a series of modified m-MTDATA derivatives were synthesized and investigated using experimental methods and theoretical tools. For example, charge transporting properties including data from commercially availablem-MTDATA are presented in Figure 1. The main synthesis conditions and comparison of thermal, photophysical and photoelectrical characteristics will be shown in the presentation, as well.

10-3 /Vs) 2

-4 (cm 10 ToF µ 10-5

m-MTDATA ABN2 -6 ABE2 Mobility Mobility 10 ABM2 AB3M2 ABMM2 ABPN2:CELIV 10-7 0 200 400 600 800 1000 Electric field1/2 (V1/2/cm1/2) Figure 1. Hole mobilities versus electric field plots for the films of new compounds.

Page- 100 GSELOP2021 Global Summit and Expo on Laser, Optics and Photonics August 23-25, 2021 | Paris, France

Keywords hole transporting materials, OLED, m-MTDATA

References [1] T. Chatterjee and K.-T. Wong, Adv. Opt. Mater., 2019, 7, 1800565. [2] S. Shahnawaz, et al. J. Mater. Chem. C, 2019, 7, 7144–7158. [3] V. Sivasubramaniam, et al. Solid State Sci., 2009, 11, 1933–1940. [4] S. C. Dong, L. Xu and C. W. Tang, Org. Electron., 2017, 42, 379–386.

Acknowledgement this research was funded by the European Social Fund under the No 09.3.3-LMT-K-712 “Development of Competences of Scientists, other Researchers and Students through Practical Research Activities” measure (Project No 09.3.3-LMT-K-712-19-0177)

Page- 101 GSELOP2021 Global Summit and Expo on Laser, Optics and Photonics August 23-25, 2021 | Paris, France D. Yano1* D. Yano1*, M.Shiraishi2, and S.Kubodera1

1Soka University,1-236 Tangi-machi, Hachioji-shi, Tokyo 192-8577, Japan. 2The University of Electro-Communications, 1-5-1 Chofugaoka, Chofu, Tokyo 182-8585, Japan. *Email: [email protected]

Laser-induced Periodic Surface Structures Formation Analysis of a Gaussian Beam Propagation on a Surface of a Glass Optical Fiber

Abstract In this paper, we studied the effect of the electric-field of a Gaussian beam propagation on the formation of laser-induced periodic surface structures (LIPSS). The results showed thatLIPSS were generated perpendicular to the Gaussian beam electricfield propagation, which enhanced the relation between the polarization of a beam and the formation of the ripples [1, 2]. LIPSS formation on optical fiber might be used as potential diffraction grating and nano-grating SPR sensor.

The experiments were conducted with femtosecond laser pulses of λ = 400 nm. The laser energy was E = 20 µJ, the repetition rate 1 kHz, and the pulse number N = 100. The laser was focused using an objective lens with NA = 0.65, to ablate the top surface of an optical fiber. Figure 1 shows the ablated surface part of the fiber, and the SEM photography of the ablated part.LIPSS periodicity was measured to be 125~200 nm, which is about half theirradiation wavelength. The ripples were formed perpendicular to the polarization of Gaussian beam propagation. Additionally, LIPSS formation was also confirmed on the side wall of microhole inside fiber. The results showed that the nanostructuresdirection also changed according with the polarization direction.

Fig. 1 LIPSS formation on the surface of optical fiber through ablation, a) schematic experimental set up, b) SEM photography of the ablation, and c) the focused part

Keywords Laser-induced periodic surface structures, femtosecond laser, Gaussian beam, beam polarization, electric field

Page- 102 GSELOP2021 Global Summit and Expo on Laser, Optics and Photonics August 23-25, 2021 | Paris, France

References [1] A. Weck, T. H. R. Crawford, D. S. Wilkinson, H. K. Haugen, and J. S. Preston, Appl. Phys. A, 89, 1001-1003, (2007). [2] K. Miyazaki, and G. Miyaji, Appl. Phys. A, 114, 177-185, (2014).

Biography

Daisuke Yano received the B.S. and M.S. degrees at Soka University, Tokyo, Japan, and now working on femtosecond laser and matter interaction towards his D.E. degree at Soka University.

Page- 103 GSELOP2021 Global Summit and Expo on Laser, Optics and Photonics August 23-25, 2021 | Paris, France A.Daskalova1* A.Daskalova1*, L. Angelova1, A.Trifonov2, D. Aceti1, E. Filipov1, I. Buchvarov2 1Institute of Electronics, Bulgarian Academy of Sciences, 72, Tsarigradsko Chaussee blvd., 1784 Sofia, Bulgaria 23Physics Department, Sofia University "St. Kliment Ohridski", 5 J. Bourchier Blvd., BG-1164 Sofia, Bulgaria *Email address: [email protected]

Studies of Ultra-Short Laser Micro-, Nanostructuring of Chitosan Coated Titanium for Orthopedic Applications

Abstract Titanium is an excellent material used in orthopedic implants since it shows excellent biocompatibility properties, however it suffers from poor bioactivity and to overcome this problem modification of the Ti implant surface is needed to improve its bioactivity. The goal of the current research was to estimate the influence of micro-, nano structured titanium with a chitosan coating on osseointegration.

Titanium matrices with a patterned surface structure were prepared using an ultra-short laser processing technology, combined with a fabricated chitosan thin film on their surfaces.

Transparent organic chitosan thin films were deposited on Ti surface to influence and improve the antibacterial property of implant biomaterial used for application in orthopedics [1], thus decreasing the risk of postoperative infection.

In this research, first Chitosan (CS) coating was applied on Ti surface, and subsequently processed via ultra-short laser pulses. Secondly, Ti matrix was laser modified with a diverse number of laser pulses and afterward CS was applied to the treated surface. It was expected that the surface micro-, nanopatterning would affect the Ti implant surface by inducing enhanced bioactivity and improved antibacterial abilities [2].We report the influence of different fs laser parameters (energy, pulse numbers) on the porosity, hydrophobicity, and morphology of Ti and CS coated Ti samples. (Figure 1).

Figure 1SEM images of femtosecond micro-, nanopatterned CS/Ti surfaces.

Page- 104 GSELOP2021 Global Summit and Expo on Laser, Optics and Photonics August 23-25, 2021 | Paris, France

The enhancement of the surface properties and micro- , nanostructure of the host matrix induced by the interaction of ultra-short laser pulses play a major role on the scaffold biological activity. The influence of applied energy on the features obtined on Ti and CS/ Ti samples were investigated by optical, atomic force microscopies and electron microscopy (SEM). In addition, we will introduce new attempts of using diverse design of host matrices for microbiological studies. This study demonstrate that fs-laser microprocessing is an attractive option to texture biocompatible surfaces, and to investigate basic aspects of the interplay between surface topography and cellular and antimicrobial behaviour.

Keywords laser micro-, nanostructuring , biomaterials, micropatterning, biomedical applications, tissue engineering.

References: 1. Lv H., Chen Z., Yan X., Cen L., Zhang X., Gao P., (2014), Layer-by-layer self-assembly of minocycline-loaded chitosan/alginate multilayer on titanium substrates to inhibit biofilm formation, Journal of Dentistry, Volume 42, Issue 11, Pages 1464-1472. 2. Estevam-Alves R., Ferreira P. , Coatrini A. , Oliveira O., Fontana C., Mendonca C., (2016), Femtosecond Laser Patterning of the Biopolymer Chitosan for Biofilm Formation, International Journal of Molecular Sciences,17, 1243.

Acknowledgments This research was funded by EU H2020 ITN Marie Sklodowska-Curie Grant Agreement No. 861138 AIMed and by Bulgarian National Science Fund (NSF) under grant number No. KP- 06-H48/6 (2020–2023).

Biography Dr Albena Daskalova has an expertise on ultra-fast laser material processing for diverse applications in tissue engineering. She is an associate professor at laboratory of Micro and Nano Photonics,Institute of Electronics-BAS, since 2019. Currently she is a head of newly formed Femtoscience application group at IE-BAS. She has obtained her PhD degree at Institute of Applied Physics in TUWIEN in 2003 and have received a Marie Curie individual grant in 2009 at Institute of Electronic Structures and Lasers- Foundation of Research and Technology (IESL- FORTH), Heraklion, Creete. Her current interests are directed towards application of laser methods for treatment of diverse biomaterials and producing matrices with enhanced surface properties for application in tissue engineering. She is a project leader and participant in numerous National and International projects funded by Bulgarian National Science Fund, Horizon 2020, Laserlab Europe and COST. She has co-authored more than 25 publications in international peer- reviewed scientific journals.

Page- 105 GSELOP2022nd 2 Global Summit and Expo on Lasers, Optics and Photonics August 22-24, 2022 | Edinburgh, Scotland