Accuracy improvement of imaging lidar based on time-correlated single-photon counting using three laser beams

Time-correlated single-photon counting (TCSPC) is one of the most active technologies for optical time-of-flight ranging and three-dimensional (3D) imaging. Ranging accuracy is one of the most critical issues of lidar system. We propose a three-laser-beam TCSPC lidar system. Besides the main measuring laser beam, the second beam is used to decrease the error caused by jitter of time synchronization. The third beam has n+0.5 time bins' difference with the main measuring beam, and it is used to correct the error caused by the discrete sampling of time-to-digital converter (TDC). To validate the feasibility of the three-laser-beam TCSPC lidar system, a series of simulation experiments using the scheme is carried out. The results show that this method is effective to improve the ranging accuracy of TCSPC lidar system.