  The integration of silicon photonics (SiPh) and phase change materials (PCMs)
has created a unique opportunity to realize adaptable and reconfigurable
photonic systems. In particular, the nonvolatile programmability in PCMs has
made them a promising candidate for implementing optical memory systems. In
this paper, we describe the design of an optical memory cell based on PCMs
while exploring the design space of the cell in terms of PCM material choice
(e.g., GST, GSST, Sb2Se3), cell bit capacity, latency, and power consumption.
Leveraging this design-space exploration for the design of efficient optical
memory cells, we present the design and implementation of an optical memory
array and explore its scalability and power consumption when using different
optical memory cells. We also identify performance bottlenecks that need to be
alleviated to further scale optical memory arrays with competitive latency and
energy consumption, compared to their electronic counterparts.
