Progress and prospects for LiDAR-oriented optical phased arrays based on photonic integrated circuits

Abstract Chip-scale LiDARs hold promise for high volume, low cost, and compact footprint. A key candidate is based on the adoption of phased array beam-forming and beam-steering in the optical domain, hence the optical phased array (OPA). Piggybacking on the rapid development of photonic integrated circuits (PICs), integrated OPAs today can emit a diffraction-limited laser beam with sub-mrad divergence and steer the beam at a point-to-point rate of ~GHz. Nevertheless, key issues remained to be addressed for practical LiDAR application. Here, we review the features and development of PIC-based OPAs from a LiDAR-oriented perspective, providing necessary backgrounds and analysis of challenges, recent breakthroughs, and long-term prospects.