CMOS-compatible Integrated Silicon Nitride Optical Phase Array for Electrically Tunable Off-chip Laser Beam Steering

We present a highly compact integrated silicon nitride optical phased array (OPA) for laser beam steering fabricated in a CMOS-compatible silicon photonic platform. The basic components to form the OPA are optimized separately, including low-loss waveguide, multi-mode interference splitter, thermo-optic phase shifter, and grating emitter array. The demonstrated OPA with 16 channels exhibits continuous thermo-optic steering in free space of ~12° with beam divergence of ~1.1° and speed of ~8 kHz. The approaches for further performance improvement are discussed.