Toward Scalable Short-Reach DWDM Optical Links

Event details Date: Wednesday, August 5, 2026 Time: 9:00 AM to 9:00 AM Location: BWRC Open Forum (2108 Allston Way) Type: Performing Arts Audience: Faculty,Students About this event The demands of today’s AI workloads are fundamentally reshaping compute infrastructure, making interconnect bandwidth a first-order scaling constraint. While conventional electrical links continue to improve, increasing channel loss and equalization complexity make it difficult to scale both reach and bandwidth density. Microring Resonator-based Dense Wavelength Division Multiplexing (MRR-DWDM) offers a short-reach optical alternative that scales aggregate bandwidth through wavelength multiplexing over a shared optical path. To establish the system-level motivation for this architecture, I analyze how higher bandwidth and larger scale-up domains can enable more efficient batching and parallelism, thereby improving attainable distributed-inference throughput under latency constraints. I complement this workload-level analysis with a qualitative comparison of bandwidth-scaling mechanisms, positioning MRR-DWDM as a promising architecture for high-bandwidth short-reach interconnects. With this system context, the remainder of the talk addresses three challenges in advancing MRR-DWDM toward a robust and scalable short-reach optical transceiver architecture. First, I develop a physics-aware statistical link framework that translates resonator dynamics, inter-symbol interference, inter-channel crosstalk, and equalization onto a common power-penalty metric, revealing the link performance landscape across transmit and receive microring quality factors. Second, I formulate DWDM wavelength initialization as a policy-driven arbitration problem and develop two autonomous algorithms: one that establishes cyclic wavelength ordering, and another that minimizes the maximum tuning distance through spectral-order matching. Third, I present two fabricated high-speed receiver prototypes, a monolithically integrated optical DWDM receiver and an ADC-based electrical receiver, as comparative case studies showing how tighter integration shifts the locus of design complexity toward cross-domain physical implementation. Collectively, these studies show that scalable... Official event details: https://events.berkeley.edu/eecs/event/325056-toward-scalable-short-reach-dwdm-optical-links