Data-compressed FMCW LiDAR with long range and high resolution using TFOC-based receiving

Despite its high range resolution, frequency modulated continuous-wave (FMCW) light detection and ranging (LiDAR) faces challenges from large data volume in long-range detections due to its de-chirping receiving principle. We propose a data-compressed FMCW LiDAR with long range and high resolution, using time-frequency optical comb (TFOC)-based receiving. By replacing the traditional single linear frequency modulating (LFM) reference signal with TFOC, the echo at any distance beats with the nearest LFM comb tooth. This approach breaks the conventional linear relationship between target range and beating frequency, resulting in a substantial decrease in beating frequency, receiver bandwidth, and data volume. An experiment shows a resolution of less than 1.87 cm for targets at equivalent free-space ranges of 0.11-0.50 m, 0.38-179 m, and 1.5-5.2 km. This is realized using a receiver bandwidth of only 125 MHz for echoes with 8 GHz sweeping bandwidth, achieving a high data compression ratio of 64. The proposed approach greatly reduces FMCW LiDAR's demand for large-bandwidth photodetectors and high-performance memory and processors.