Solid-State Optical Beam Scanner for LiDAR Application

Abstract

We demonstrate a silica arrayed waveguide grating (AWG) based on optical phased array (OPA) solid-state beam scanner with a low total insertion loss of 4.04~dB. The 64-channel AWG OPA, combined with a digital MEMS device, achieves two-dimensional (2D) optical beam steering via wavelength tuning from 1535~nm to 1565~nm, providing a field-of-view (FOV) of 15.8$^{\circ}$(H)$\times$12$^{\circ}$(V). Furthermore, the FOV is efficiently expanded to 76.58$^{\circ}\times$48$^{\circ}$ using a compact lens relay system without deteriorating the beam profile. A metalens with a hyperbolic cylindrical phase gradient reshapes the elliptical output beam into a circular profile, yielding a full-angle divergence of 0.125$^{\circ}$(H)$\times$0.095$^{\circ}$(V). In addition, we propose and experimentally demonstrate a synchronous transceiving FMCW ranging scheme using a single silica AWG OPA chip, functioning as both transmitter (Tx) and receiver (Rx), offering a promising approach with a negligible errors and highlighting its potential for future solid-state FMCW LiDAR sensors.