Modeling of Perimeter Gated SPAD-based Direct Time-of-Flight Sensor for Low Light LiDAR Applications

This paper presents a novel model of perimeter gated single photon avalanche (SPAD)-based direct time-of-flight (TOF) sensor for low light detection and ranging (LiDAR) applications. A perimeter gated SPAD (PGSPAD) is an improved version of SPAD which incorporates an extra field modulating gate terminal to mitigate perimeter edge breakdown without unnecessarily increasing the device size. Additionally, the extra gate terminal of PGSPAD device provides controls for the device’s noise, sensitivity, and dynamic range. In order to predict and optimize the performance of the system, we have taken into account all the fundamental factors that affect a typical LiDAR acquisition system, including background noise and device noise in the developed model. Results show that the applied gate voltage of PGSPAD helps to improve the signal-to-noise ratios (SNR) by reducing the device noise in low light scenarios. Additionally, the model incorporates the coincidence detection to minimize background noise.