Ultrafast parallel single-pixel LiDAR with all-optical spectro-temporal encoding
Zihan Zang, Zhi Li, Yi Luo, Yanjun Han, Hongtao Li, Xuanyi Liu, H. Y. Fu
Abstract
Light detection and ranging (LiDAR) with scanning beam has been widely used in autonomous driving and large-scale manufacturing, where the fast-changing scene is of great interest. However, the acquisition rate of current LiDAR is limited by beam steering speed and the round-trip delay, hindering the development of video-rate LiDAR. Here, we uniquely combine all-optical encoders with wavelength-division multiplexing devices to implement spectro-temporal encoding on the illumination light. Parallel detection and fast spectral scanning can be achieved with only one laser and one single photodetector. Our result shows the fastest single-pixel LiDAR to date, and the detection speed can be multiplied with scalability. We demonstrate 3.56-fold improvement of speed for a maximum of 75 m detection range compared with a serial LiDAR. A record acquisition rate of 21.38 MHz for a maximum of 25 m detection range is obtained. This approach has the potential to break the limitation on current ultrafast single-pixel LiDAR and opens a new paradigm for ultrafast-frame-rate imaging systems.