Interleaved resistive micro-heater for switching phase-change materials integrated in silicon photonics

Phase-change material (PCM)-based photonic devices provide non-volatile control over phase and amplitude. This can potentially transform large-scale photonic integrated circuits by enabling ultra-low power, highly reconfigurable, and compact photonic integrated circuits for applications such as photonic switching arrays, RF photonics, and optical information processing. Here, we demonstrate a new approach, to our knowledge, for the electrical switching of PCMs using an interleaved resistive micro-heater structure that provides an efficient switching mechanism by overcoming some of the limitations of existing micro-heater designs and can also potentially increase PCM lifetime by eliminating the electrical current flowing through the PCM. The proof-of-concept device was fabricated in a commercial silicon photonics foundry using our post-processing technique with only a few fabrication steps and coarse-resolution laser-writing lithography. The device achieved 0.775 dB/µm of amplitude switching contrast using a thin layer (12.5 nm) of GST.