High-Endurance, Low-loss Sb2Se3 Optical Switches on Silicon Nitride using Transparent Conductive Heaters
We report an electrically actuated, low-loss non-volatile optical switch based on the phase-change material (PCM) Sb2Se3 integrated on a silicon nitride (Si3N4) platform. The device is fabricated using an 8-inch wafer-scale process flow, demonstrating the feasibility of scalable manufacturing for photonic integrated circuits (PICs). By employing transparent indium tin oxide (ITO) micro-heaters, reversible switching between the amorphous and crystalline states is achieved with an extinction ratio of 25~dB and an endurance exceeding 140 million switching cycles, establishing a new benchmark for non-volatile integrated photonic memory and reconfigurable architectures. Furthermore, multi-level operation beyond 6 bits can be repeatably demonstrated by tailoring the electrical pulse widths, enabling precise control of the optical phase. These results highlight a scalable and energy-efficient platform for high-density programmable and non-volatile photonic integrated systems.