Photonic latch memory could enable optical processor caches that run up to 60 GHz, twenty times faster than standard caches — optical SRAM stores and outputs data entirely as light, but density challenges remain

Akhilesh Jaiswal (left) and Md Abdullah-Al Kaiser.

Researchers have built a prototype that paves the way for enabling light-powered processor caches that can run at up to 60 GHz in the future, or roughly 20 times faster than some modern processor caches. The functional regenerative "photonic memory latch," fabricated on the commercially available GlobalFoundries’ 300mm Fotonix photonics platform, is designed as an optical counterpart to a standard SRAM bit, and the team positions it as a missing component for fully photonic processors. However, further density improvements will be needed before the tech can be fully integrated into optical processors.

The prototype addresses two bottlenecks that plague modern high-performance systems — interconnect delay and the cost of repeatedly converting information between light and electricity.