Large field of view and high-resolution beam steering based on power-efficient polarization multiplexing optical phased arrays.

High-performance optical phased arrays (OPAs) are pivotal for realizing chip-scale, all-solid-state light detection and ranging (LiDAR). In this work, we propose and experimentally demonstrate a power-efficient and polarization-multiplexing silicon photonic OPA with a large field of view (FOV) for high-resolution beam steering. The FOV in orthogonal dimensions is enhanced by harnessing a sparse array and a dual-polarization multiplexing method. For large-scale integration, a power-efficient phase shifter for both polarizations is designed by employing a dual-waveguide dense superlattice array. Further combined with the proposed subwavelength grating, a large antenna array aperture as well as high angular resolution are realized in both dimensions. A 128-channel OPA chip is fabricated and subsequently underwent electro-optical packaging. The experimental results show that the phase shifter exhibits low excess losses of 0.77 dB and 0.87 dB for two polarization states. The power consumptions are both below 5.8 mW/π, which is only 1/4 compared to the conventional designs. The demonstrated OPA offers a wide FOV of 80° × 29.4° and a narrow beam divergence of 0.12° × 0.10°.