Towards Scalable, Energy-Efficient and Ultra-Fast Optical SRAM

Abstract: Optical static random access memory (O-SRAM) is one of the key components required for achieving the goal of ultra-fast, general-purpose optical computing. We propose and design a novel O-SRAM using fabrication-friendly photonics device components such as cross-coupled micro-ring resonators and photodiodes. Based on the chosen photonic components, the memory operates at a speed of 20 Gb/s and requires ultra-low static (switching) energy of ~ 16.7 aJ/bit (~ 1.04 pJ/bit) to store a single bit. The footprint of the bit cell is ~ 2400 {\mu}m^2. The proposed O-SRAM can be configured in a 2D memory array by replicating the bit-cells along rows and columns for creating ultra-large scale on-chip optical memory sub-system. Such manufacturing-friendly, large-scale optical-SRAM could form the underlying memory backbone for photonics integrated circuits with wide applications in novel computing and networking.