Detection performance improvement method of single-photon LiDAR by the combination of speckle suppression with adaptive adjustment of aperture diameter and spatial correlation method

Abstract

The flash array imaging LiDAR with the laser transmitted by the multimode fiber (MMF), will get a low detection performance which is caused by the severe transmitting light field's speckle and high-noise intensity in the daylight condition. In this paper, a scheme of the combination of speckle suppression with adaptive adjustment of aperture diameter (AAAD) and spatial correlation method is proposed to improve the detection performance. In which the speckle suppression by vibrating the MMF with the optimal vibration parameters can effectively suppress the speckle, and the AAAD can help to get the optimal triggering probability, besides, the spatial correlation method can increase the detection number and suppress the speckle in a further step. Firstly, the proposed scheme is built based on the speckle suppression and single-photon triggering probability model. Secondly, the proposed scheme is verified by the theoretical analysis, and it can effectively improve the detection performance under the low SNR condition. Finally, the experimental verification under the high-noise intensity condition is carried out, and the speckle contrast is reduced from 1.247 to 0.057, which is decreased by 95.4%; the target recovery ratio or signal detection probability is increased from 28.8% to 97.7%, which is improved by 239.2%. This work is useful for the effective detection of the laser MMF coupling transmitted single-photon LiDAR under daylight conditions.