Silicon Photonics FMCW LiDAR Chip With a Slow-Light Grating Beam Scanner

Abstract

Photonic crystal slow-light gratings fabricated using Si photonics enable high-speed, high-resolution, and wide field-of-view two-dimensional beam scanning via the thermo-optic effect. In this paper, we built a frequency-modulated continuous-wave light detection and ranging system on a chip by combining a beam scanner with Ge photodiodes for delay homodyne coherent detection. Emitting and scanning frequency-swept laser beam, point cloud images of 154 × 32 = 4928 points were obtained. The real-time operation and velocity imaging were also demonstrated. This device is expected to detect Lambertian targets over long distances in the 100-m class by reasonably reducing chip and optics losses and suppressing internal noise components.