Coherent Ising machine: a photonic Ising model solver based on degenerate optical parametric oscillator network
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.
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.
Dr. Ken-Tye Yong
Director of the Bio Devices and Signal Analysis (VALENS)
School of Electrical and Electronic Engineering
Nanyang Technological University (NTU)
Tuesday, Nov. 20th, 3 - 4 pm, ESB 2001
Nanomaterials have been applied in healthcare applications such as cancer imaging, lymph node mapping and brain diseases therapy. These nanomaterials can be engineered to serve as a platform for challenges in highly sensitive optical diagnostic tools, biosensors, and guided imaging and therapy. The versatility of nanomaterials may provide the keys to improve diagnostics and therapy of human diseases. In this talk, we will highlight the use of nanomaterials with different sizes, compositions, and shapes for nanomedicine applications. This talk is intended to promote the awareness of past and present developments of nanomaterials in biomedical fields, the potential toxicity of nanomaterials, and the approaches to engineer new types of safe nanomaterials, whereby encouraging researchers to think about exciting and promising biophotonic and nanomedicine applications with nanomaterials in the future.
Friday Nov 9th, 1pm, Elings 1605
The past decade has seen accelerated progress in III-V semiconductor infrared photodetector technology. The advent of the unipolar barrier infrared detector device architecture has in many instances greatly alleviated generation-recombination (G-R) and surface-leakage dark current issues that had been problematic for many III-V photodiodes. Meanwhile advances in a variety type-II superlattices (T2SLs) such as InGaAs/GaAsSb, InAs/GaSb, and InAs/InAsSb, as well as in bulk III-V material such as InGaAsSb and metamorphic InAsSb, have provided continuously adjustable detector cutoff wavelength coverage from the short wavelength infrared (SWIR) to the very long wavelength infrared (VLWIR). The confluence of these developments has led to a new generation of versatile, cost-effective, high-performance infrared detectors and focal plane arrays based on robust III-V semiconductors, providing a viable alternative to HgCdTe (MCT).
Women in Photonics 2018