 Monday March 11th, 11am, ESB 1001 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. Refreshments provided! 
12:00 PM Friday, March 1st in Elings 1605
Pizza will be provided! 
Thursday, Feb 28, 12 - 1 pm, ESB 1001
Refreshments will be provided 
Friday, Feb 8, 1 – 2 pm, ESB 1001 More than a billion individual VCSELs were deployed before 2017 as optical sources within short-reach optical interconnects as well as for position sensing. In 2018, laser manufacturing began the era of 2D VCSEL arrays. As a result more than a billion new VCSELs were added in a single year to provide new functionality for consumer electronics products. In this talk I will report on the development of coherently coupled VCSEL arrays which may enable new VCSEL applications. I will discuss the physics of operation for antiguided photonic crystal VCSEL arrays, and will show their potential application for electronic beam steering and high speed digital data transmission. Refreshments Provided!
Friday, Jan. 25th at 12:00 PM in ESB 1001 Pizza will be provided Thursday, Jan. 17th, 12 pm, ESB 1001  If you're interested in joining, get a head start by joining one of our parent professional organizations: IEEE Photonics Society, OSA, or SPIE!
Friday, Jan 18, 12 – 1 pm, Elings 1605 As various systems and networks in our society grow larger and more complex, analysis and optimization of such systems are becoming increasingly important. Such tasks are classified as combinatorial optimization problems, which are generally difficult to solve with current digital computers. It is well known that combinatorial optimization problems can be converted to ground-state-search problems of the Ising model, a theoretical model for the interacting spins. Recently, several approaches to find solutions to the Ising model using artificial spin systems have been studied intensively. A coherent Ising machine (CIM) is one of such systems in which degenerate optical parametric oscillators (DOPO) pulses are used as artificial spins. By using a long-distance (typically 1 km) fiber cavity that contains a phase sensitive amplifier based on a periodically poled lithium niobate waveguide, we can generate thousands of DOPO pulses multiplexed in time domain. Since a DOPO phase only takes either 0 or p at above threshold, we can stably express an Ising spin with a DOPO by allocating phase 0 (p) as spin up (down). The “spin-spin interaction” can be implemented by using a measurement-feedback scheme, with which we can effectively realize mutual injection of lights among thousands of DOPO pulses. The networked DOPOs are most likely to oscillate at a phase configuration that best stabilize the whole network, which gives the solution to the given Ising problem. Based on this scheme, we realized a CIM with all-to-all-coupled 2000 DOPO pulses, by which we could find good solutions to 2000-node combinatorial optimization problems in less than 100 microseconds. In the talk, I will describe the basic principle and the experimental details of the CIM, as well as our effort for finding its applications. Refreshments Provided!
Tuesday, Dec. 11th at 12:00 PM in Elings 3001
Pizza will be provided!
Tuesday Dec. 4th at 12:30 pm in ESB 1001 Pizza will be provided! This is the start of the weekly student lecture series IEEE Photonics is hosting throughout Winter 2019! Ryan DeCrescent and Robert Zhang will be presenting their talks.   Wednesday November 28th, 2 pm, ESB 1001 Alex is an entrepreneur with a track record of building teams that take ideas from the research laboratory through commercialization. Alex was a co-founder, the CEO, and Board Director of Aurrion from 2008-2016 which was a fabless semiconductor company that developed photonic integrated circuits for data center networking applications. The business was acquired by Juniper Networks. Alex worked for IBM, Lawrence Livermore National Laboratory, and Intel prior to founding Aurrion. Alex earned his M.S & Ph.D. from UCSB and is an alumnus of the Harvard Business School Owner/President Management Program. In his downtime, Alex enjoys riding off road motorcycles, playing guitar, smoking meat and reading books. Alex loves spending time with his wife and daughter going to live shows, travelling and eating weird stuff. Refreshments Provided! |
