Intellectual Merit: The photonic interconnect architectures and design techniques proposed here aim to significantly improve interconnect robustness, energy efficiency, and bandwidth density, which is necessary for continued scaling of future computer systems. While progress has been made in photonic interconnects, the optimal interconnect architecture which most efficiently leverages these optical devices for off-chip and network-on-chip applications is still an open question. This work?s research goal is to develop robust energy-efficient transceivers for a unified inter- and intra-chip photonic interconnect architecture based on integrated ring resonator modulators and waveguide photodetectors. To accomplish this goal, an ultra-fast system-level optimization framework for photonic on-chip networks and inter-chip links that investigates trade-offs in bandwidth density, energy efficiency, and interconnect throughput will be developed to compare photonic interconnect technologies and leveraged in the design of the proposed architecture. Novel circuit topologies will be developed that address challenges imposed due to nanometer transistor scaling properties, such as transistor reliability constraints conflicting with voltage-swing requirements of optical source devices and shrinking transistor gain and growing mismatch having a large impact on receiver sensitivity. The combination of system level optimization with circuit-level accuracy and new ultra-efficient circuit topologies enables architectures capable of leveraging photonic interconnects? properties of extreme low latency and high bandwidth to realize completely new computing models with orders of magnitude performance improvement. Broader Impact: The explosion in interconnect bandwidth capacity provided by this photonic interconnect architecture will allow the realization of numerous transformative applications, such as future smart mobile devices capable of Tflop/s performance, multi-channel high-resolution magnetic resonance imaging, and exascale supercomputers. Interconnect architectures developed with the proposed optimization framework will have a broad impact on not only the US semiconductor industry, but also on the sustainability and security of the nation as a whole, as it will dramatically reduce the energy these integrated systems demand. This project will include an interdisciplinary educational program involving 1 Ph.D. and 5 undergraduate students, with a commitment in several engaging outreach activities to foster the representation of women and minority groups. These activities include participating in a four-week summer workshop for K-12 school teachers and also annual one-week summer camps for high school students. Project results will be broadly disseminated by inclusion in the syllabi and website of a new graduate course entitled ?Optical Interconnect Circuits and Systems? and through publication in national and international journals and conferences.
