Abstract: Graphene has emerged as an alternative saturable absorber to other semiconductors due to its nearly constant broadband absorption of 2.3%. It has been shown that graphene and graphene-based nanomaterials can be used as efficient saturable absorbers to generate ultrashort pulses from lasers operating in the near- and mid-infrared. However, the 2.3% absorption of the monolayer graphene introduces operational challenges to the lasers with low gains. To obviate such challenges, the Fermi level position of the graphene can be varied to control the amount of absorption at the desired wavelength. For this purpose, chemically- or electrostatically-doped novel graphene architectures with reduced optical insertion losses can be used to optimize the power performance of the femtosecond lasers.

In this talk, the use of carbon-based saturable absorbers to generate ultrashort pulses from solid-state lasers will be presented and their current drawbacks will be discussed. This will be followed by the overview of the possible approaches, which have been demonstrated to shift the Fermi level of graphene to control the amount of absorption at the desired wavelength. At this point, the voltage-controlled graphene-based supercapacitor architectures proposed by our groups will be demonstrated and the femtosecond pulse generation results obtained with these devices will be discussed.

In the remainder part of the talk, Dr. Baylam will give information about the opportunities provided by The Optical Society (OSA) to the graduate students and early career researchers.

Prof. Armani is the head of a research lab at USC where she "develops advanced materials and integrated optical devices that can be used in portable disease diagnostics and telecommunications." Read more about her research at https://armani.usc.edu/. 

Nanomateial-Enhanced Integrated Photonics
Abstract: Integrated photonics offers a potential alternative to integrated electronics, with reduced heating and faster data rates. However, to achieve many of the desired performance metrics, it is necessary to combine disparate material systems. Heterogeneous integration is plagued by challenges, including different lattice constants, thermal expansion coefficients, and fabrication compatibilities, all of which can impact the final device performance ad lifetime. Therefore, new materials and material systems as well as fabrication methods are desired. One approach is to combine the conventional top-down fabrication methods and optical materials, such as silica and silicon, with bottom-up fabrication and nano-materials. These hybrid systems provide access to optical behavior and performance not attainable with conventional approaches. This talk will present several of the new integrated hybrid photonic devices being developed in the Armani Lab, including approaches based on nonlinear organic small molecules and plasmonic nanoparticles to develop Raman lasers and frequency combs.

Grade 6+ ONLY
Proof of U.S. Persons required:
ALL tour attendees must bring ONE of the following IDs:
(1) U.S. Passport
(2) U.S. Naturalization Certificate
(3) Permanent Resident/Green Card
(4) U.S. Birth Certificate AND either Photo ID or Social Security card
Note: For parents or chaperones, a driver's license is NOT valid proof. Yes, even children need this proof.

Megan Birney is President of Unite to Light, a nonprofit organization that manufactures and distributes solar lights to people living without access to electricity across the globe.
Throughout her career Megan has focused on increasing access to clean, renewable energy. She started her career at the Community Environmental Council where she ran the Energy Efficiency and Renewable Energy Programs, including creation of Solarize, a residential group-purchasing program in California. While there she advocated for renewable energy projects and policies leading to over 1 GW of solar in the Central California region.  Then Megan served as Director of Strategic Affairs and Product Manager for a commercial solar financing company that was aiming to address the financing gap for nonprofits and small businesses. Megan is also a Water Commissioner for the City of Santa Barbara. She has a Masters in Public Policy from the University of Southern California, and a BA in Sociology from the University of California, San Diego. Megan has taught a courses on energy sources, uses and issues through the University of California extension program. 

Photonics and Global Aid & Development: the Power of Solar Lights
Unite to Light, a nonprofit founded at UCSB, manufactures and distributes solar lights and solar power to people living without electricity. Hear from President & CEO Megan Birney about how the organization was founded, the innovation of their lights, and the impact around the world. 

Fluency Lighting Technologies is an early stage start-up company developing technology out of UC Santa Barbara. At Fluency, we are creating next-generation bright and narrow-beam light sources for highly efficient illumination, using laser technology and materials design. Our focus is the development of low-cost, optical platforms that convert laser diode emission into high-quality white light in various light levels, beam angles, and color temperatures, designed for customer-driven metrics, in applications where energy-saving LED technology is not used because of the limited light output from an LED.

In this talk I will highlight the history of GaN research at UCSB, and some of the key breakthroughs and technologies developed by the faculty, students and staff.  Starting with one MOCVD system, UCSB Faculty were the first University world-wide to achieve a blue GaN Laser in 1996. In 2000, Prof. Shuji Nakamura joined the Faculty and along with Prof. DenBaars, Prof. Speck and Prof. Mishra co-founded the Solid State Lighting and Energy Electronics Center (SSLEEC), which has now become one of the largest academic GaN based Photonic and Electronic research centers in the world. SSLEEC has played a key role in developing numerous breakthroughs, some of which have led to the realization of high-efficiency Solid-State Lighting, which the Dept. of Energy estimates will save the equivalent annual electrical output of about fifty 1,000-megawatt power plants. 

​Looking into the future we see next generation GaN Laser Diode based solid state lighting as impacting high brightness specialty lighting. We have demonstrated laser based white lighting with luminous efficacies of 87 lm/watt, and over 1000 lumens from a single emitter.  In addition, tunnel junctions have been employed to achieve vertical cavity surface emitting lasers (VCSELs) in the blue spectral region. Blue and green lasers and Micro-LEDs based on GaN materials are expected to enable new full color projections displays for cinema, office and augmented reality (AR) applications.

Two-dimensional Van der Waals materials have emerged as a very attractive class of optoelectronic material due to the unprecedented strength in its interaction with light. In this talk I will discuss approaches to realize quantum photonic devices by integrating these 2D materials with microcavities, and metamaterials. I will first discuss the formation of strongly coupled half-light half-matter quasiparticles (microcavity polaritons) and their optical and electrical control in the 2D transition metal dichacogenide (TMD) systems. Prospects of realizing condensation and few photon nonlinear switches using Rydberg states in TMDs will also be discussed. Following this, I will discuss the broadband enhancement of light-matter interaction in these 2D materials using photonic hypercrystals and chiral metasurfaces. Finally, I will talk about room temperature single photon emission from hexagonal boron nitride and the prospects of developing deterministic quantum emitters using them through strain engineering. The realization of room temperature single photon emitters and few photon
nonlinear switches using 2D materials presents an attractive direction for robust next generation quantum photonic technologies.​

Abstract
The continuing growth in demand for bandwidth (from residential and business users), necessitates significant research into new advanced technologies that will be employed in future broadband communication systems. Two specific technologies, becoming increasingly important for future photonic systems, are wavelength tunable lasers and optical frequency combs. Although these topics have been studied for over two decades their significance for the development of future ultra-high capacity photonic systems has only recently been fully understood. Wavelength tunable lasers are currently becoming the norm in optical communication systems because of their flexibility and ability to work on any wavelength. However, as their operating principles are different to standard single mode lasers they can effect how future systems will operate. For example as optical transmission systems move towards more coherent transmission (where the data is carried using both the intensity and phase of the optical carrier), the phase noise in these tunable lasers will become increasingly important. Optical frequency combs also have many applications for future photonics systems, and for telecommunications they can be used to obtain the highest spectral efficiency in optical transmission systems by employing the technology of optical frequency division multiplexing (OFDM), and also for generation of high frequency RF signals in future 5G networks. Wavelength tunable lasers and optical frequency combs are thus topics at the leading edge of current photonics systems research, and their detailed understanding promises new applications in all-optical signal processing, optical sensing and metrology, and specifically telecommunications. This talk will focus on the development and characterization of various wavelength tunable lasers and optical frequency combs, and then outline how these sources can be employed for developing optical transmission systems and networks which make the best use of available optical spectrum.

Biography
Liam Barry received his BE (Electronic Engineering) and MEngSc (Optical Communications) 
degrees from University College Dublin in 1991 and 1993 respectively. From February 1993 until January 1996 he was employed as a Research Engineer in the Optical Systems Department of
France Telecom's Research Laboratories (now known as Orange Labs) in Lannion, France, and as a result of this work he obtained his PhD Degree from the University of Rennes in France. In February 1996 he joined the Applied Optics Center in Auckland University, New Zealand, as a Research Fellow and in March 1998 he took up a lecturing position in the School of Electronic Engineering at Dublin City University, and established the Radio and Optical Communications Laboratory. From April 2006 until February 2010 he served as Director of The Rince Institute, an interdisciplinary research center with over 100 researchers. He is currently a Professor in the School of Electronic Engineering, a Principal Investigator for Science Foundation Ireland, and Director of the Radio and Optical Communications Laboratory. His main research interests are; all-optical signal processing, optical pulse generation and characterization, hybrid radio/fibre communication systems, wavelength tuneable lasers for reconfigurable optical networks, and optical performance monitoring. He has published over 200 articles in international peer reviewed journals, 250 papers in international peer reviewed conferences, and holds 10 patents in the area of optoelectronics. He has been a TPC member for the European Conference on Optical Communications (ECOC) since 2004, and a TPC member for the Optical Fibre Communication Conference (OFC) from 2007 to 2010, serving as Chair of the Optoelectronic Devices sub-committee for OFC 2010.