Single Photon Detectors for Automotive LiDAR Applications: State-of-the-Art and Research Challenges

Due to the fast growth of the autonomous vehicles industry, there is a growing need for distance sensing systems. Among such systems, the light detection and ranging (LiDAR) system is very attractive because of their wide detection range, good spatial resolution, and high precision. For various LiDAR systems, detectors that have single photon counting (SPC) abilities are becoming increasingly popular as they have high sensitivity and can achieve long detection range. However, many publications about LiDAR only focus on the data processing and the algorithms, without sufficient considerations on the sensor-design stage. Only a few studies investigated the sensor's performance in various LiDAR applications. To assist in the future improvement and application of SPC LiDAR, this article provides a new perspective by reviewing the optical sensors and the related circuits architectures in LiDAR systems, focusing on automotive applications. The principles, architectures, emerging techniques, research challenges and future directions are critically discussed.