Scaling up silicon photonic-based accelerators: Challenges and opportunities

Digital accelerators in the latest generation of complementary metal-oxide-semiconductor processes support, multiply, and accumulate (MAC) operations at energy efficiencies spanning 10-100 fJ/Op. However, the operating speed for such MAC operations is often limited to a few hundreds of MHz. Optical or optoelectronic MAC operations on today's SOI-based silicon photonic integrated circuit platforms can be realized at a speed of tens of GHz, leading to much lower latency and higher throughput. In this Perspective, we study the energy efficiency of integrated silicon photonic MAC circuits based on Mach-Zehnder modulators and microring resonators. We describe the bounds on energy efficiency and scaling limits for N x N optical networks with today's technology based on the optical and electrical link budget. We also describe research directions that can overcome the current limitations.& nbsp;(c) 2022 Author(s). All article content, except where otherwise noted, is licensed under a Creative Commons Attribution (CC BY) license(http://creativecommons.org/licenses/by/4.0/).