Demonstration of a Solar-Blind Single-Photon Imaging Lidar Based on SiC Ultraviolet Avalanche Photodiodes

In this work, a prototype solar-blind single-photon imaging lidar based on SiC ultraviolet (UV) avalanche photodiodes (APD) is demonstrated. The SiC APD with a peak responsivity at ~280 nm can greatly lessen the strict solar-blind filtering requirement for the system. When characterized by using a gated quenching circuit, the SiC APD operating in Geiger mode could exhibit a room temperature single photon detection efficiency of ~27% with a dark count probability of $1.59\times 10 ^{-2}$ . Based on the SiC APD, a 266 nm nanosecond pulsed laser, a galvanometer scanner and a time-correlated single-photon counter, 3-dimensional depth image with $128\times 128$ resolution is realized by the prototype system in daylight. The average ranging accuracy of the system is found within 28 mm based on current setup.