CMOS SPAD Sensors for Solid-state LIDAR

Single-photon avalanche diode (SPAD) arrays implemented in CMOS are one of the key technologies behind solid-state LIDAR. CMOS SPAD arrays in image sensor format, with integrated photon timing and processing, have enabled all-digital receiver units to be realised that, combined with pulsed, multi-element laser sources, are now supporting demanding applications such as automotive LIDAR. We review important advances at device-, circuit- and system-level that have helped propel SPADs to the forefront of LIDAR innovation and consider potential future directions in SPAD architectures for LIDAR.