Solid-state Swept Source Lidar: single-sweep-per-frame 3D FMCW lidar with OPA-plus-dispersion beam steering

Solid-state and compact beam steering is critical for next-generation lidar (light detection and ranging). We previously proposed and demonstrated Swept Source Lidar, a method that combines broad continuous wavelength sweeping with dispersive beam steering for frequency-modulated continuous-wave (FMCW) ranging. In that system, the dispersive scan was assigned to the fast axis, requiring multiple wavelength sweeps to form a single frame. Here, we reassign the dispersive beam steering to the slow axis and use a silicon-photonic optical phased array (OPA) on the fast axis, enabling one frame per single wavelength sweep. The 32-channel OPA with Si <i>p</i>-<i>i</i>-<i>n</i> phase shifters provides ∼50° horizontal active beam steering, while the dispersive slow axis adds ∼5° vertical beam steering via wavelength tuning. With a tunable-laser sweep rate of 10 Hz, we perform FMCW 3D imaging at a frame rate of 10 Hz. This chip-scale architecture demonstrates, to our knowledge, the first active, dual-axis, on-chip, fully solid-state swept source lidar that forms a complete 2D frame within a single, broad, continuous wavelength sweep.