Noise-tolerant LiDAR approaching quantum-limited precision

Abstract

Quantum-inspired imaging techniques have been proven to be effective for LiDAR with the advances of single photon detectors and computational algorithms. However, the quantum-limited performance is still far from its ultimate limit set by the quantum fluctuations of signal and noise photons. In this work, we propose and demonstrate LiDAR from the detection perspective for approaching quantum-limited performance. A photon-number-resolving detector is introduced to accurately reconstruct the echo signals in a wide photon-flux range and an active photon number filter is further developed to overcome the heavy background noise. The Fisher information of this LiDAR based on a coherent source is only 0.04 dB below the quantum limit in intensity detection when mean signal photon number is 10. An improvement of 41.17 dB in the signal-to-background ratio is achieved with the proposed LiDAR in daytime, and the accuracy of intensity estimation is consistent with the theoretical prediction, which helps to improve the quality of reconstructed images. This work provides a fundamental strategy for constructing a noise tolerant LiDAR approaching quantum-limited precision.