Out-of-plane phase change memory cell switching for optical computing

Phase Change Materials (PCMs) have found success in Photonic Integrated Circuits (PICs) because of their significant optical property changes between amorphous and crystalline states. These properties enable applications such as optical switches, multi-level memories, and neuromorphic hardware accelerators. Typically, programming PCM cells in-plane, optically or electronically, is done through additional optical inputs or electronic contacts. To avoid this, an out-of-plane approach using a Vertical-Cavity Surface-Emitting laser (VCSEL) array with flip-chip bonding is employed. Combined with height control and focusing of the laser through micro-3d printed structures and lenses the intensity on the PCM cells can be maximized. This approach enhances the design flexibility for multi-PCM cell circuits.