The OptoElectronic Computing Group (OECG), under the direction of Professor Sadik Esener at the University of California San Diego, presently consists of 4 professional and post-doctoral researchers and 12 graduate students. The goal of the OECG is to research and develop massively parallel optoelectronic computer systems through the optimal utilization of micro-electronic and photonic technologies. A coherent and cohesive plan of research is being pursued, spanning the areas of optoelectronic materials and devices, diffractive and micro-optics, non-linear optics, optical storage technologies, parallel computing algorithms and architectures including database and neural systems, computer modeling, and optoelectronic packaging. In addition, the group has extensive collaborations in many of these areas with faculty members and their graduate students at various academic institutions as well as with several R&D companies. The Optoelectronic Computing Group is an integral part of the Heterogeneous Optoelectronic Technology Center (HOTC), a center for excellence funded by DARPA, that also includes research groups at the University of California Santa Barbara, University of California Los Angeles, and Cornell University. The group is also the leading insitution of the 3D OptoElectronic Stacked Processors Consortium, a joint Government-Industry-University effort.

The structure and operation of the Optoelectronic Computing Group emphasizes the fact that this field of research is highly interdisciplinary, involving not only optoelectronic material scientists and device engineers, but also optical component and optical system engineers, as well as computer engineers and scientists. To reach the goal of developing massively parallel optoelectronic computer systems, frequent interactions between researchers in these diverse disciplines have proven to be very crucial. Therefore, the team at UCSD works very closely together through internal meetings, and through joint contract support with the collaborating faculty members and industry researchers.

Major pioneering contributions have already been made in the past by the OptoElectronic Computing Group at UCSD, such as integration of optical transmitters and receivers with electronic logic circuits, diffractive optics design and fabrication, novel addressing schemes for parallel access optical disks and three-dimensional optical memories, new optoelectronic parallel computing architectures, and models for optoelectronic devices. The research effort undertaken at UCSD has now become a leading activity in the field of optoelectronic computing.

As the need for more computing power grows, either the micro-electronic devices in a computer have to work faster, or many processors have to be operated in parallel. With rapid advances in VLSI technology, micro-electronic devices are quickly approaching their fundamental limits. In addition, the performance of a computing system is dependent on the communication system that links the processors in parallel and on the communication system with the storage units. Thus, as the communications grow longer and denser, due to architectural requirements and/or physical system dimensions, pure electronic interconnections experience great difficulties in terms of latency, power dissipation and crosstalk. Our studies show that by providing free-space optical interconnections between the processing planes, many of the communication problems among the electronic circuits can be solved. Thus, there is a need to examine when, in terms of processor size, processor array dimensions, and memory characteristics, optical interconnections should be used to help electronic computing to achieve higher performance. This means that the design trade-offs between micro-electronics and photonics for various system applications need to be determined.

To bring optoelectronic parallel computing into reality, there is a need to resolve the technical problems of interfacing micro-electronics and photonics by developing appropriate light transmitters and receivers. The yield problems in fabrication need to be investigated, and new fault tolerant system architectures that support optical interconnections need to be explored. Also, there is a need to address the issues of optoelectronic system packaging, system reliability and testing, and system design automation that link algorithms and architectures to device and component design, fabrication, and assembly.

The availability of basic micro-electronic and photonic equipment and facilities in one location at UCSD allows the group to meet the challenges of building prototypes of parallel optoelectronic computers. The OptoElectronic Computing Group has a significant amount of its own research equipment and facilities, and it shares other equipment with various research groups in the ECE department at UCSD. The group has currently access to over 2,500 sq. ft. of optics space and 1,600 sq. ft. of micro-fabrication space. For optoelectronic device design and fabrication, CAD tools (Epoch, Tanner, Magic, VHDL, Spice), a class 100 clean room for photolithography, a class 1000 clean rooms for diffusion furnace, PECVD, LPCVD, evaporation RIE, MBE, and r.f. sputtering systems are available to the group's members. For micro-optics and diffractive optics design and fabrication, there are also CAD tools (CodeV, Optica), electron beam lithography, and reactive ion beam etching. For characterization and testing of optoelectronic materials, devices, and components as well as for optoelectronic system prototyping, the group has electronic instrumentation (e.g. C-V, G-V, IC testers, TDR, surface profilers, X-ray diffraction, electron microscope, etc.), a number of lasers (e.g. GaAs, Nd:YAG, Argon, Ti:Sapphire, Dye, He-Ne, Co2 etc.), high quality optics and vibration isolated tables in all the laboratories.

The Optoelectronic Computing Group has established several joint projects with various aerospace and communication companies, some through joint contracts to the US Departments of Defense and Commerce. This type of collaboration offers numerous opportunities for interactions between professional researchers in industry and the group's graduate students. The industrial collaborators benefit from this program by attending the group's workshops and by having first hand access to the research reports, as well as other publications. Specific face-to-face meetings with group researchers, whose expertise may assist the industrial collaborators in their research and development effort, are also available. To aid in their recruiting effort, industrial collaborators are informed of senior graduate students about to enter the job market.

The UCSD Optoelectronic Computing Group provides a unique framework to perform research in optoelectronics by combining experts in critical disciplines to the future of computing systems, state of the art facilities, and collaboration opportunities with the industry.

If you would like more information about the group, collaboration opportunities, or for graduate studies, please do not hesitate to contact us.