Improving noise performance of a flash LiDAR sensor using perimeter-gated SPADs for low-light imaging

This paper aims to improve the noise performance of a flash LiDAR Sensor using perimeter-gated SPADs for low-light imaging. A perimeter-gated SPAD is a new version of SPAD having an additional gate terminal. The extra gate terminal mitigates the perimeter edge breakdown without changing the size of device. In addition, applied gate voltage can modulate the breakdown voltage of SPAD devices resulting in improvements in performances such as dark count rate, dynamic range, etc. We developed a new analytical model that includes all the features to verify the performance of the proposed perimeter-gated SPAD-based flash LiDAR system. The analytical model replicates a DTOF flash LiDAR system, including the optics, illumination source, and perimeter-gated SPAD-based CMOS image sensor architecture. In addition, we include the coincidence window to improve the background noise for the image reconstruction process. Finally, the performance of a perimeter-gated SPAD-based flash LiDAR system is analyzed for a wide range of different gate voltages and various coincidence thresholds for low-light scenarios using the model. This paper focuses on both device noise and background noise performance of the DTOF flash LiDAR system. Consequently, the perimeter-gated SPADbased LiDAR system sensors exhibit promise for usage in low-light virtual prototyping applications such as 3D scanners, security surveillance, gesture recognition, and the automobile sector.