SiN‐On‐SOI Optical Phased Array LiDAR for Ultra‐Wide Field of View and 4D Sensing

Abstract 3D imaging techniques are facilitating autonomous vehicles to build intelligent systems. Optical phased arrays (OPAs) featured by all solid‐state configurations are becoming a promising solution for 3D imaging. However, the majority of state‐of‐art OPAs commonly suffer from severe power degradation at the edge of the field of view (FoV), resulting in limited effective FoV and deteriorating 3D imaging quality. Here, the chained grating antenna and the vernier concept is synergized to design a novel OPA for realizing a record wide 160°‐FoV 3D imaging. By virtue of the chained antenna, the OPA exhibits less than 3‐dB beam power variation within the 160°FoV. In addition, two OPAs with different pitches are integrated monolithically to form a quasi‐coaxial Vernier OPA transceiver. With the aid of a flat beam power profile provided by the chained antennas, the OPA exhibits uniform beam quality at an arbitrary steering angle. The superior beam steering performance enables the OPA to accomplish 160° wide‐FoV 3D imaging based on the frequency‐modulated continuous‐wave (FMCW) LiDAR scheme. The ranging accuracy is 5.5‐mm. Moreover, the OPA is also applied to velocity measurement for 4D sensing. To the best of knowledge, it is the first experimental implementation of a Vernier OPA LiDAR on 3D imaging to achieve a remarkable FoV.