Photonic non-volatile memories using phase change materials

TL;DR

This paper introduces an all-photonic, non-volatile memory system using phase-change materials integrated with nanophotonic waveguides, enabling multi-level operation and potential neuromorphic computing applications.

Contribution

It presents a novel photonic memory device based on phase-change materials that modulate resonator properties for non-volatile data storage and processing.

Findings

High sensitivity to crystallization degree in GST enables multi-level memory states.

Reversible control of resonance wavelength and extinction ratio demonstrated.

Potential for neuromorphic computing due to non-volatile, tunable photonic states.

Abstract

We propose an all-photonic, non-volatile memory and processing element based on phase-change thin-films deposited onto nanophotonic waveguides. Using photonic microring resonators partially covered with Ge2Sb2Te5 (GST) multi-level memory operation in integrated photonic circuits can be achieved. GST provides a dramatic change in refractive index upon transition from the amorphous to crystalline state, which is exploited to reversibly control both the extinction ratio and resonance wavelength of the microcavity with an additional gating port in analogy to optical transistors. Our analysis shows excellent sensitivity to the degree of crystallization inside the GST, thus providing the basis for non-von Neuman neuromorphic computing.