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EE298‐5 AND PLASMONICS SEMINAR – SPRING 2011 unit value: 1 instructor: Prof. Ivan Kaminow, [email protected] coordinator: Lea Barker, [email protected] class time: FRIDAYS, 11:00AM ‐ 12:30, 521 CORY HALL pre‐requisite: An interest in Photonics and/or Plasmonics. May be taken for credit and/or fun. website: http://inst.eecs.berkeley.edu/~ee298‐5/sp11/ plasmonics list: [email protected]

This course is intended to give students at the advanced undergraduate or graduate level, and researchers, insight into current research based on a series of invited talks.

SCHEDULE:

1/21 ‐ Prof. REUVEN GORDON, U. Victoria, Canada, “Challenging the Limits of Diffraction”

Abstract: This talk will show ways of challenging three limits of optical diffraction. First, it will be shown how to focus below the Abbe diffraction limit [1]. Next it will be shown how to squeeze light through small holes in a metal screen, allowing for 100% transmission in some cases, in contrast to Betheʹs aperture theory as found in textbooks [2,3]. This has interesting applications for biosensors. Finally, it will be shown how to optically trap nanoparticles with powers orders of magnitude smaller than required by conventional by Rayleigh scattering formulations [4], which has interesting applications for manipulating viruses and quantum dots. Theoretical and experimental results will be presented.

(1) R. Gordon, ʺProposal for superfocusing at visible wavelengths using radiationless interference of a plasmonic array,ʺ Letters, 102, 207402 (2009). (2) R. Gordon, A. G. Brolo, A. McKinnon, A. Rajora, B. Leathem, and K. L. Kavanagh, ʺStrong polarization in the optical transmission through elliptical nanohole arraysʺ Physical Review Letters, 92, 037401, (2004). (3) R. Gordon, ʺBetheʹs theory for aperture arrays,ʺ Physical Review A, 76, 053806, (2007). (4) M. L. Juan, R. Gordon, Y. Pang, F. Eftekhari, R. Quidant, ʺSelf‐induced back‐action optical trapping of dielectric nanoparticles,ʺ Nature , advanced publication online 11 Oct. (2009).

Bio: Reuven Gordon received his B.A.Sc. in (1997) and his M.A.Sc. in

1 (1999) from the University of Toronto. He received a Ph.D. in Physics (2002) from the University of Cambridge. In 2002, he joined the University of Victoria, where he currently holds a Canada Research Chair in Nanoplasmonics and an Associate Professor position in the Department of Electrical and Computer Engineering. In 2009, Dr. Gordon was a visiting Professor at the Institute for Photonic (ICFO ‐‐ Barcelona, Spain). He has received a Canadian Advanced Alliance Award, an Accelerate BC Industry Impact Award and he was co‐inventor of the mode‐locked VCSEL (patents held by Hitachi). Dr. Gordonʹs recent works on nanoplasmonics, biosensors and optical trapping have been featured in the news sections of Nature, Nature and IEEE Spectrum. Dr. Gordon has authored and co‐authored over 60 journal papers (including 5 invited contributions) with 1250 indexed journal citations and he has co‐authored two book chapters. Dr. Gordon is a Senior Member of the IEEE and a Professional of BC.

1/28 – Prof. J‐P. REITHMAIER, Institute of Nanostructure , U. Kassel, Germany, “Nanostructured for Optoelectronic Applications: From Single Photon Emission to High Power Quantum Dot ”

Abstract: An overview will be given on a part of our research of the last few years on nanostructured semiconductors with the focus on III‐V materials. The strength of nanostructure technologies is the control of material and device properties by the geometry and the arrangement of nano objects. Additional degrees of freedom allow tailoring of material and device properties not possible with conventional technologies. Major technologies involved are self‐organized growth techniques of III‐V quantum dots including also position‐controlled QDs and high resolution electron beam lithography with high aspect ratio etching techniques. Examples will be given, which are covering a wide span of application areas from single photon emitters for quantum information processing, high speed lasers and amplifiers for optical data‐ and telecom and high‐power quantum dot lasers for coolerless optical pump modules.

Biography: Johann Peter Reithmaier studied Physics at TU Munich and made his PhD at Siemens and Walter‐Schottky‐Institute in 1990. Until 1992, he worked as Postdoc at IBM in Rüschlikon, Switzerland on III/V epitaxy. In 1992, he joined University of Würzburg where he built up a research group working on nanostructured semiconductors and their applications in optoelectronic devices. In 2005 he became a full professor of physics and director of the Institute of Nanostructure Technologies and Analytics at the University of Kassel. He is author or co‐author of more than 480 journal and conference papers (240 in refereed journals, 2 books, 3 book articles and 75 invited talks). He is a member of the Deutsche Physikalische Gesellschaft (DPG) and of IEEE Photonics Society (Fellow of IEEE since 2011).

2 1/28 EXTRA SEMINAR: 3‐4pm in 521 Cory Hall Prof. WOLFGANG STOLZ, Material Sciences Center and Faculty of Physics, Philipps‐ University, Marburg, Germany & CTO NAsP III/V GmbH Marburg, “Novel dilute nitride III/V‐ system for the monolithic integration to Si‐ microelectronics”

Abstract: In recent years the class of dilute nitride III/V‐semiconductors and corresponding heterostructures are gaining increasing interest both from fundamental as well as applied point of view. This is caused by their unique optoelectronic properties and in particular by the novel conduction band formation process leading to an extreme band gap bowing with increasing N‐content in the crystal.

The novel material system Ga(NAsP) can be grown lattice‐matched to (001) Si‐substrate. The incorporation of N in the Ga(NAsP)‐material allows for a significant reduction in the lattice constant, which leads on one side to a dislocation free deposition. On the other side the specific conduction band formation process in these materials is used to realize a direct band gap semiconductor. By applying a variety of physical investigation techniques the high crystalline as well as the direct band gap character of the novel Ga(NAsP)‐material system have been verified. Ga(NAsP)/(BGa)(AsP)‐MQWH were grown on exact oriented (001) Si substrates embedded in thick (BGa)P separate confinement hetero‐layers by metalorganic vapour phase epitaxy (MOVPE). The incorporation of B into GaP and Ga(AsP) allows for a precise strain management of the whole III/V laser stack towards the lattice constant of Si. The optoelectronic properties and first lasing characteristics of Ga(NAsP)‐ MQWH on (001) Si‐substrate will be presented and discussed.

These results form the basis for a unique realization of monolithic integration of III/V‐based optoelectronic and Si‐microelectronic functionalities in the near future. The challenges of this integration concept will be discussed and possible solutions will be presented.

Biography: Wolfgang Stolz received the M.S. in physics (diploma) from the University of Heidelberg (Germany) in 1982. He performed his Ph.D. work in physics at the Max‐Planck‐Institute for Solid State Research, Stuttgart (Germany) and obtained the Ph.D. degree from the University of Stuttgart (Germany) in 1986. He received the Habilitation degree in from the University of Marburg (Germany) in 1994. Currently he is co‐head of the Structure and Technology Research Laboratory in the Material Sciences Center at Philipps‐University of Marburg (Germany), Adjunct Professor at the Optical Sciences Center of the University of Arizona, Tucson (USA) and Chief Technology Officer at NAsP III/V GmbH Marburg (Germany).

3 His fields of research include the epitaxial growth of III/V‐compound semiconductor materials and related heterostructures, the (opto)electronic properties and the integration of these heterostructures on Si‐substrate as well as realization of novel device concepts for electronic, laser and solar cell applications.

2/4 – YONGMIN LIU, Prof. Xiang’s Lab, UCB , “Transformation for Plasmonics and Photonics”

Abstract: has recently attracted extensive interests, since it provides a novel design methodology for manipulating light at will. In this talk, I will first briefly discuss the interplay among transformation optics, and plasmonics. Then I will show that surface plasmon polaritons (SPPs) can be manipulated in a prescribed manner by carefully controlling the dielectric material properties adjacent to a metal based on the transformation optics technique. Since the metal properties are completely unchanged, it provides a straightforward way for practical implementations. This approach can assist to tightly bound SPPs over a broad wavelength range at uneven and curved surfaces, where SPPs would normally suffer significant scattering losses. In addition, a plasmonic Luneburg lens and a plasmonic bend are demonstrated. Finally, I will present a new approach of designing a single photonic element that possesses simultaneously multiple distinct functions, such as double beam shifters along two different directions. These findings open up a new avenue to effectively scale down the size of future optical systems.

Biography: Yongmin Liu received his Ph.D. from the University of California at Berkeley in 2009, under the supervision of Prof. Xiang Zhang. Currently he is a post doctoral researcher in the same group. Dr. Liu’s research interests include nanophotonics, metamaterials and plasmonics. His recent awards include Chinese Government Award for Outstanding Self‐Financed Students Abroad (2009), International Society for (SPIE) Scholarship Award (2008), and Tse‐Wei Liu Memorial Fellowship at UC‐Berkeley (2008).

2/11 – IVAN P. KAMINOW, EECS, UC Berkeley, “Lightwave Modulators: Early Research at Bell Labs”

Abstract: Ted Maiman’s announcement of the ruby laser in May 1960 created great excitement worldwide, and particularly at Bell Labs. I was in the Microwave Systems Research Lab, soon to become the Lightwave Systems Research Lab, in Holmdel, NJ. Many of my colleagues decided to pursue laser research. Based on my experience with microwave systems, I decided to explore broadband light modulators that would be key for any telecom system. In my talk, I plan to touch on some of the highlights of a 15‐year period of research on electrooptic

4 modulators in the Bell Labs ambience. I include a 9 GHz travelling wave modulator, studies of electrooptic materials and photonic integrated circuits.

Biography: Ivan Kaminow retired from Bell Labs in 1996 after a 42‐year career (1954‐1996), mostly in lightwave research. At Bell Labs, he did seminal studies on electrooptic modulators and materials, Raman scattering in ferroelectrics, integrated optics (including titanium‐diffused lithium niobate modulators), semiconductor lasers (including the DBR laser, ridge waveguide InGaAsP laser and multi‐frequency laser), birefringent optical fibers, and WDM lightwave networks. Later, as Head of the Photonic Networks and Components Research Department, he led research on WDM components (including the erbium‐doped fiber amplifier, waveguide grating router and the fiber Fabry‐Perot resonator), and on WDM local and wide area networks. Earlier (1952‐1954), he did research on microwave antenna arrays at Hughes Aircraft Company.

After retiring from Bell Labs, he served as IEEE Congressional Fellow on the staffs of the House Science Committee and the Congressional Research Service in the Library of Congress. From 1997 to 1999, he returned to Lucent Bell Labs as a part‐time Consultant. He also established Kaminow Lightwave Technology to provide consulting services to various technology companies, and to patent and litigation law firms. In 1999 he served as Senior Science Advisor to the Optical Society of America in Washington.

He received degrees from Union College (BSEE), UCLA (MSE) and Harvard (AM, Ph.D.). He was a Hughes Fellow at UCLA and a Bell Labs Fellow at Harvard. He has been Visiting Professor at Princeton, Berkeley, Columbia, the University of Tokyo, and Kwangju University (Korea). Currently, he is Adjunct Professor in EECS at University of California, Berkeley, where he has been teaching since 2004. He is a member of the National Academy of Engineering.

2/18 – FRANK BRUECKNER, Institute of Applied Physics, U. Jena, Jena, Germany, “Advanced mirror concepts for high‐precision metrology”

Abstract: Commercially available highly‐reflective dielectric devices are commonly built of multilayer coatings containing at least two different layer materials. Due to the complex alternating coating technique, a critical laser induced damage threshold, and most severely a remarkable internal thermal noise level, these dielectric stacks appear as a drawback for various applications such as in the field of optical high‐precision measurements. We investigate the capability of so‐called guided‐mode resonant waveguide gratings as alternative mirror setups with a rapidly reduced coating thickness. By utilizing the resonant behavior of light coupling of a subwavelength periodic structure in a high refractive index layer attached to a

5 low refractive index substrate (or layer) high reflectivity can be achieved. It is shown that by introducing an effective low‐index layer instead of a homogeneous one, earlier grating configurations can even be advanced to purely monolithic mirror architectures. Without the need of adding any other material to the mirror substrate, this new approach might give a promising solution for long‐standing problems as mentioned above. Within this work the first monolithic high‐reflectivity surface mirror was realized from a single silicon crystal and had a record reflectivity of 99.8 percent.

Biography: Frank Brueckner is a PhD student at the Microstructure Technology / Microoptics group of the Institute of Applied Physics under supervision of Dr. Ernst‐Bernhard Kley and Prof. Andreas Tünnermann, at the Friedrich Schiller University of Jena – Jena, Germany. From April‐July, 2006, he held a Fellowship of the German Academic Exchange Service, participating in the NSF program “International Research Experience for Undergraduates” at the Laser Laboratory group of the College of Optics CREOL (University of Central Florida, Orlando). Research topic: “Two‐photon polymerization for nano‐optical devices.” His Diploma in General Physics (similar to M.Sc.) was obtained in 2006 at U. Jena, at the Ultrafast Optics group of the Institute of Applied Physics.

2/25 – MARIO PANICCIA, Director, Photonics Technology Lab, Intel, “Bridging Photonics and Computing”

Abstract: The silicon chip has been the mainstay of the electronics industry for the last 40 years and has revolutionized the way the world operates. Today a silicon chip the size of a fingernail contains over one billion transistors and has the computing power that only a decade ago would take up an entire room of servers. Silicon photonics that mainly based upon silicon on insulator (SOI) has recently attracted a great deal of attention since it offers an opportunity for low cost opto‐electronic solutions for applications ranging from telecommunications down to chip‐to‐chip interconnects as well as possible applications in new emerging areas such as optical sensing and or bio‐medical applications.

Recent advances and research breakthroughs in silicon photonic device performance over last few years have shown that silicon can be considered as a material onto which one can build future optical devices. While significant efforts are needed to improve device performance and to “commercialize” these technologies, progress is moving at a rapid rate. If successful, silicon may similarly come to dominate the optical communications as it has the electronics industry.

This presentation will provide an overview of silicon photonics research at Intel Corporation, describe some of the recent advances including the recently announced demonstration of an integrated silicon photonics optical link operating at 50Gbps and the 6 scalability of this to >1Tbps. In addition the presentation will provide an overview and discuss the potential applications and future opportunities for enabling “photonics” in and around the PC and server platform.

Biography: Dr. Mario Paniccia is an Intel Fellow and Director of the Photonic Technology Lab at Intel Corporation. Mario currently directs a research group focused in the area of Silicon Photonics. The team is developing silicon‐based photonic building blocks for future use in enterprise and data center communications. Mario has worked in many areas of optical technologies during his career at Intel including optical testing for leading edge microprocessors, optical communications and optical interconnects. His teams pioneering activities in silicon photonics have led to many firsts such as the first silicon modulator with bandwidth >1GHz (2004) and then the first at 40Gb/s (2007). The first continuous wave Silicon laser breakthrough (2005) and together with UCSB, the world’s first “Hybrid Silicon Laser” (2006). Mario has won numerous awards including in November 2004 Mario was awarded by Scientific American to be one of the top 50 researchers for his teams work in the area of silicon photonics. In October 2008 Dr Paniccia was being by R&D Magazine as “ of the year” for his teams pioneering research in the area of Silicon Photonics. He has published numerous papers, including 3 Nature papers, 3 book chapters, and has over 65 patents issued or pending. He is a fellow of IEEE, OSA and SPIE. Mario earned a B.S. degree in Physics in 1988 from the State University of New York at Binghamton and a Ph.D. degree in Solid State Physics from Purdue University in 1994.

3/4 – Prof. JOE KAHN, E. L. Ginzton Laboratory, Stanford – “Understanding and Exploiting Multimode Fiber Dispersion”

Abstract: Multimode fiber (MMF) is widely used in short‐reach systems, such as data‐center networks. Random perturbations cause coupling between modes having different group delays (modal dispersion), strongly limiting bit rate  distance products (to about 10 Gbit/s  300 m in current systems). For decades, modal coupling and dispersion have been modeled using incoherent power coupling models. By using a coherent field coupling model, we predicted the existence of principal modes, which are linear combinations of ideal modes that are free of modal dispersion to first order. As random mode coupling evolves over time, the principal modes and their delays change. Using adaptive optics to launch into a principal mode, we have achieved transmission far beyond previous bit rate  distance limits (10 Gbit/s  11 km or 100 Gbit/s  2.2 km). We will discuss further increasing transmission capacity in short‐ reach MMF systems by spatial multiplexing in several principal modes. Finally, we will discuss spatial multiplexing in MMF to increase capacity in long‐haul systems using inline optical amplifiers and coherent receivers. Mode‐dependent gain poses serious challenges, which we hope to overcome by exploiting innate properties of multimode propagation.

7 Biography: Joseph M. Kahn received the A.B., M.A. and Ph.D. degrees in Physics from UCB in 1981, 1983 and 1986, respectively. From 1987‐1990, he was at AT&T Bell Laboratories, Crawford Hill Laboratory, in Holmdel, NJ. He demonstrated multi‐Gbit/s coherent transmission systems, setting world records for receiver sensitivity. From 1990‐2003, he was on the EECS faculty at UCB, performing research on optical and wireless communications. Since 2003, he has been on the EE faculty at Stanford University. Current research interests include: rate‐adaptive and spectrally efficient modulation and coding methods, coherent detection and associated digital signal processing algorithms, digital compensation of fiber nonlinearity and high‐ speed transmission in multimode fiber. In 2000, he co‐founded StrataLight Communications (now Opnext Subsystems), a leading supplier of transmission subsystems for high‐capacity terrestrial networks.

3/11 – Prof. S.L. CHUANG, U. Illinois at Urbana‐Champaign, ECE Dept., “Metal‐Cavity NanoLasers: How Small Can They Go?”

Abstract: Since the invention of the first ruby laser in 1960 and semiconductor lasers in 1962, the size of lasers has been reduced significantly. Ultra‐small lasers such as vertical‐cavity surface‐ emitting lasers, microdisk lasers, and photonic crystal lasers have been realized toward micro‐ and nanoscales. Most recently, metal‐cavity nanolasers of subwavelength dimensions have been demonstrated either by optical pumping at low to room temperatures or by pulsed electrical injection up to 298K. In this talk, I will present the design and experimental demonstration of our proposed nanoscale metal‐cavity surface‐emitting lasers, which operate in continuous‐wave mode at room temperature with electrical injection. Nanoscale metal‐ cavity lasers have advantages, such as subwavelength optical confinement, excellent isolation from device crosstalk, and excellent thermal conduction for heat removal. Inspite of the metal loss, the large negative plasma permittivities of metals at optical frequencies help with the optical confinement. Nanoscale semiconductor lasers have potential applications for the future generation of digital photonic circuits; for example, intrachip and interchip optical interconnect.

Biography: S. L. Chuang received the BS degree from National Taiwan University in 1976; and the MS., E.E., and Ph. D. degrees from MIT in 1980, 1981, and 1983, respectively. He joined in 1983 the Department of Electrical and Computer Engineering, University of Illinois at Urbana‐ Champaign, where he is currently the R. MacClinchie Distinguished Professor. His research interest is on semiconductor nanophotonic devices. He is the author of Physics of Photonic Devices (2nd edition, 2009) and Physics of Optoelectronic Devices (1st edition, 1995), Wiley. He is a Fellow of the American Physics Society, IEEE, and Optical Society of America. He received Engineering Excellence Award from OSA in 2004, the IEEE/LEOS Distinguished Lecturer

8 Award for 2004 to 2006, and the William Streifer Scientific Achievement Award in 2007. He received the Humboldt Research Award for Senior U.S. in 2008‐2009. He was elected a member of the Board of Governors for IEEE Photonics Society for 2009‐2011.

3/18 – Dr. FRED A. KISH, Jr., VP, Optical Integrated Components Group, INFINERA, “Current Status of Coherent Large‐Scale InP Photonic Integrated Circuits”

Abstract: The current state‐of‐the‐art for large‐scale InP photonic integrated circuits (PICs) is reviewed with a focus on the devices and technologies that are driving the commercial scaling of these highly integrated devices. Specifically, high‐capacity dense wavelength division multiplexed (DWDM) transmitter and receiver photonic integrated circuits (PICs) are reviewed with a focus next generation devices: >500 Gb/s coherent multi‐channel transmitter and receiver InP PICs. These large‐scale PICs integrate hundreds of devices onto a single monolithic InP chip and enable significant reductions in cost, packaging complexity, size, fiber coupling, and power consumption which enable benefits at the component and system level.

Biography: Fred A. Kish received his B.S., M.S., and Ph.D. degrees in electrical engineering from the University of Illinois at Urbana‐Champaign in 1988, 1989, and 1992, respectively. His Ph.D. was obtained under the direction of Professor Nick Holonyak, Jr. on ʺNative Oxides on Aluminum‐Bearing III‐V Semiconductors with Applications to High‐Performance Laser Diodesʺ. This work is part of the core Al‐bearing III‐V native‐oxide technology that has enabled the development of the highest performance VCSELs and has been licensed to VCSEL manufacturers throughout the world. From 1992 to 1999, he was at Hewlett‐ Packard’s optoelectronics division where he co‐invented and led the commercialization of the highest performance (efficiency) red‐orange‐yellow visible LEDs produced at the time (wafer‐bonded transparent‐substrate AlGaInP LEDs). The efficiencies of these devices exceeded those of incandescent and halogen lamps. From 1999 to 2001, he was with Agilent Technologies as the department manager of III‐V R&D and Manufacture in the Network Solution Division. There, he led a department that developed commercially viable 2.5Gb/s VCSELs and VCSEL/detector arrays (12 x 2.5 Gb/s) for next generation fiber‐optic transceiver and parallel‐optic transmitter/receiver products.

In 2001, he joined Infinera as Vice President of photonic integrated circuit (PIC) development and manufacturing and later as Sr. Vice‐President of the Integrated Optical Components Group. At Infinera, he co‐invented and led the effort to research, develop, and commercialize the first practical (commercially deployed) large‐scale InP PICs. These large‐scale PICs are at the core of Infinera’s optical network products that have achieved #1 market share in North America and #2 market share worldwide in the long‐haul DWDM optical communications market.

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Dr. Kish is a Fellow of the Optical Society of America and the IEEE and has been awarded the 1987 E.C. Jordan Award and the 1992 R.T. Chien Award from the University of Illinois, the 1996 Adolph Lomb Award from the OSA, the International Symposium on Compound Semiconductors 1997 Young Scientist Award, the 1999 IEEE LEOS Engineering Achievement Award, the 2000 University of Illinois Electrical and Computer Engineering Young Alumni Achievement Award, and the 2004 IEEE David Sarnoff Award. He has coauthored over 100 U.S. Patents and over 50 peer‐reviewed publications.

3/25 – NO SEMINAR – SPRING RECESS.

4/1 – Prof. ALAN WILLNER, Steven & Kathryn Sample Chair in Engineering, USC, “Tailoring of Dispersion, Nonlinearity and Polarization in On‐Chip Slotted Waveguides”

Abstract: On‐chip optical structures have the potential to play a significant role in high‐capacity optical interconnections. First, we will discuss the use of slotted waveguides for tailoring chromatic dispersion and nonlinearity over a wide spectral range. Such optical waveguides can alter the data signals traversing the structure. There are several scenarios in which one may want to tailor the dispersion and nonlinearity, including for transmission, signal processing, wavelength conversion, and phase and polarization manipulation. Second, we will discuss the use of novel ring‐resonator configurations in efficient optical interconnections for: (a) low‐power modulators, and (b) data modulation and demodulation of phase‐shift‐keyed signals.

Biography: Alan Willner (Ph.D., Columbia) has worked at AT&T Bell Labs and Bellcore, and is the Steven & Kathryn Sample Chair in Engineering at USC. His awards include: Intʹl Fellow of the Royal Academy of Engineering, NSF Presidential Faculty Fellows Award from the White House, Packard Foundation Fellowship, NSF National Young Investigator Award, Fulbright Foundation Senior Scholars Award, OSA Forman Engineering Excellence and Bookham Leadership Awards, IEEE Photonics Society Distinguished Lecturer, IEEE / OSA / SPIE Fellow, and Eddy Paper Award from Pennwell Publications for the Best Contributed Technical Article. Prof. Willner has been President of IEEE Photonics Society; Editor‐in‐Chief of Optics Letters, IEEE/OSA Journal of Lightwave Technology, and IEEE Journal of Selected Topics in Quantum Electronics; and Co‐Chair of OSA Science and Engineering Council; General Co‐Chair of CLEO. He has 875 publications, including one book and 25 patents.

NOTE: There will be two seminars on Friday, April 8.

4/8 (1) – Prof. FENG WANG, UCB Physics – “Tunable Optical Phenomena in Graphene”

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Abstract: Graphene is a two‐dimensional material with unusual electrical and optical properties. I will describe how the elastic and inelastic optical processes in grapheme can be controlled through electrical gating. I will also discuss plasmon excitations of the two‐dimensional electron gas in grapheme and its potential for tunable terahertz metamaterials.

Biography: Feng Wang has been an Assistant Professor in the Department of Physics at UC Berkeley since 2007. Professor Wang is the Principal Investigator of the Ultrafast Nano‐Optics Group, which is associated with both the Dept. of Physics, and the Materials Sciences Division of Lawrence Berkeley National Laboratory. The research group is interested in light‐matter interaction in , with an emphasis on novel physical phenomena emerging in nanoscale structures and at surfaces/interfaces. See: http://blogs.ls.berkeley.edu/fengwang/

Feng Wang gained his BS (Physics) from Fudan University, Shanghai, China in 1999, and received his Ph.D. (Physics) from Columbia University, New York in 2004. From 2005‐2007, he was a Miller Fellow in the Miller Institute for Basic Science at UC Berkeley. Other awards and fellowships include: Alfred P. Sloan Research Fellow (2008), Outstanding Young Researcher Award, Overseas Chinese Physics Assn. (2008), NSF CAREER Award (2009), International Union of Pure and Applied C10 Young Scientist Prize (2009), DOE Early Career Award (2010), and a Packard Fellowship (2010).

4/8 (2) – SEBASTIAN PAUL STARK, Max Planck Institute for the Science of Light, Erlangen, Germany, (Postdoc candidate), “Novel Aspects of Pulse Propagation in Photonic‐ Crystal Fibers”

Abstract: We exploit the high designability of solid‐core photonic‐crystal fibers (PCFs) and engineer devices with unusual linear and nonlinear properties. This is used to manipulate the spectro‐ temporal characteristics of propagating laser light.

First, we demonstrate that the behaviour of ultrashort pulses is strongly affected by axially‐ varying fibers. Surprisingly, the shrinking core size leads to a blue‐shift of the soliton center wavelength, counteracting the Raman red‐shift of ultrashort pulses. Another striking effect is the existence of multiple scattering events between solitons and linear radiation, increasing dramatically the blue edge of the spectrum. We used such taper transition to generate supercontinua extending to a record‐breaking 280nm.

11 Another promising fiber design is given by a submicron‐core fiber. This device maximizes the nonlinearity, leading to broad spectra even for very low lasing powers. We discuss the various pulse propagation regimes that arise for different pump parameters. In collaboration with the Max Planck Institute for (Garching, Germany) we use this device to generate frequency combs for astro‐metrology.

Last, we demonstrate that the large nonlinear interaction of the light with the core material can also be used to shape the temporal characteristics of the optical field. We present the synthesis of a train of sub‐50 fs pulses, having repetition rates in the THz region. Additionally, it is shown that the temporal spacing between these pulses can be tuned by varying the fiber and laser properties.

Biography: Stark is just finishing his Doctoral thesis in nonlinear photonics under the supervision of Prof. P. St.J. Russell.

4/15 – Dr. JIM SCHUCK, Staff Scientist, Molecular Foundry, LBNL, “Life Beyond Diffraction: Nano Imaging with Optical Antennae”

Abstract: The control of light, and therefore information, at nanoscale dimensions is critical for addressing, and ultimately providing solutions to, a broad range of pressing scientific and societal challenges. In our nano‐optics lab, we are particularly interested in harnessing local light‐matter interactions for the elucidation of fundamental properties of quantum, optical and optoelectronic structures, where the critical length scales and time scales involved are in the nm‐scale and sub‐picosecond regimes, respectively. In this talk, I will highlight our efforts in hyperspectral nano‐imaging. To date, there have been significant limitations to optical near‐field imaging spectroscopy, precluding the investigation of many classes of nanoscale structures and devices. To fully explore heterogeneous nanoscale structures optically, we have engineered and fabricated (with high yield) optical antennae‐based scan probes, enabling, for the first time, hyperspectral nano‐Raman imaging.

Biography: Jim Schuck is currently a Staff Scientist at the Molecular Foundry located at Lawrence Berkeley National Laboratories. He earned his B.A. in Physics at UC Berkeley, and his Ph.D. in Applied Physics with Prof. Robert Grober at Yale University. He did his postdoctoral studies at Stanford University with Prof. W. E. Moerner, studying optical nanoantennas and single‐molecule spectroscopy. Jim has co‐authored four book chapters on plasmonics and high‐resolution imaging spectroscopy, and his research currently focuses on plasmonic device applications and nanoscale spectroscopic investigations of localized states and defects in novel materials.

12 4/22 – MATTEO STAFFARONI, PhD candidate (Prof. Eli Yablonovitch), UCB, “Circuit Analysis in Metal‐Optics, Theory and Applications” **Postponed until next semester**

4/22 – OWEN MILLER, PhD candidate (Prof. Eli Yablonovitch), UCB, “Nano‐photonic Inverse Design”

Abstract: Inverse design represents an important new paradigm in nano‐photonics. Over the past few decades, substantial progress has been made in computing the electromagnetic response of a given structure. We present computational methods for solving the inverse problem of finding a dielectric structure that produces a desired electromagnetic response. The mathematical framework of shape calculus, coupled with parameter‐free level set methods, enables one to efficiently find non‐intuitive, superior designs relatively quickly. Applications of the method to resonant waveguides and optical cloaking will be presented.

Biography: Owen Miller is a fourth‐year graduate student in the Yablonovitch research group at UC Berkeley. He graduated in 2007 from the University of Virginia, where he doubled‐majored in electrical engineering and physics. In addition to inverse design he is researching methods for achieving high efficiencies in solar cells. He was a recipient of the NSF Graduate Research Fellowship.

4/29 – Dr. THOMAS M. BAER, Executive Director, Stanford Photonics Research Center, Stanford University, “Biomedical Applications of Dynamic Quantitative Imaging: Oncology, Developmental Biology, and Neuroscience”

Abstract: Our understanding of the molecular basis of life has been greatly expanded by the development of highly precise analytical instruments capable of measuring tens of thousands of molecular targets simultaneously. In parallel with these revolutionary developments, new imaging technologies have also rapidly evolved, providing unsurpassed resolution and highly accurate three dimensional images of cells and organ systems in living organisms. A growing research frontier is at the intersection of these two areas: correlating dynamic quantitative imaging data with precise multi‐parameter molecular analysis of DNA, RNA, and proteins in vivo, and from samples harvested from live tissue. Working at this intersection requires mathematical modeling of complex molecular data sets and development of automated image analysis and feature extraction algorithms of large three dimensional image data sets. In this seminar I will discuss several examples of recent research using this approach in studies in human development biology, neuroscience, and oncology.

Biography:

13 Dr. Baer is currently the Executive Director of the Stanford Photonics Research Center and a member of the Applied Physics Department at Stanford University. His research is focused on developing imaging and analysis technology for exploring the molecular basis of developmental biology and neuroscience.

From 1996 to 2005 Dr. Baer was CEO, chairman, and founder of Arcturus Bioscience, a biotechnology company located in Mountain View, CA, which he established in 1996. Arcturus Bioscience pioneered the area of Microgenomics by developing and manufacturing laser microdissection instrumentation and integrated bioreagent systems. Arcturus developed products that allowed precise genetic analysis of microscopic tissue samples and which were integrated into a new generation of cancer diagnostic tests. Prior to Arcturus, Dr. Baer was Vice President of Research at Biometric Imaging, where he led an interdisciplinary group developing products with applications in the areas of AIDS monitoring, bone marrow transplant therapy, and blood supply quality control. From 1981 to 1992 Dr. Baer was at Spectra‐Physics, Inc., where he held positions as Vice‐President of Research and Spectra‐ Physics Fellow. While at Spectra‐Physics his research focused on ultra‐fast lasers, optical pulse compression, diode‐pumped solid‐state lasers, and .

Dr. Baer has made major contributions in the areas of biotechnology, quantum electronics, and laser applications. He is listed as an inventor on 60 patents and is a co‐author on many peer reviewed publications in a number of different scientific fields. His commercial products have received many industry awards for design innovation. Co‐founder of four companies in Silicon Valley, he was named entrepreneur of the year for emerging companies in Silicon Valley in 2000 by the Silicon Valley Business Journal. Dr. Baer graduated with a BA degree in Physics Magna Cum Laude from Lawrence University and received his MS and Ph.D. degrees in from the University of Chicago. He is also an alumnus of Harvard Business School and in 1994 he received the Distinguished Alumni Award from Lawrence University. He has been elected to the status of Fellow in two international scientific societies, the American Association for the Advancement of Science and The Optical Society of America (OSA), and served as the President of OSA in 2009.

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