Scalability analysis of optical Beneš networks based on thermally/electrically tuned Mach-Zehnder interferometers

Silicon Photonic interconnects are a promising technology for scaling computing systems into the exa-scale domain. However, significant challenges exist in terms of optical losses and complexity. In this work, we examine the applicability of thermally/electrically tuned Beneš network based on Mach-Zehnder Interferometers for on-chip interconnects as regards its scalability and how optical loss and laser power scale with the number of endpoints. In addition, we propose three hardware-inspired routing strategies that leverage the inherent asymmetry present in the switching components. We evaluate a range of NoC sizes, from 16 up to 1024 endpoints, using 4 realistic workloads and found very promising results. Our routing strategies offer an optical loss reduction of up to 32% as well as a laser power reduction by 33% for 32 endpoints.