High-Precision Noncooperative Target Ranging at the Single-Photon Level Based on Dual-Comb Asynchronous Optical Sampling

In the field of high-precision, large-scale equipment manufacturing and assembly, it is important to achieve high-precision distance and topography measurements of noncooperative targets with complex topography. However, ensuring a high measurement accuracy under a weak echo remains challenging. Here, a high-precision noncooperative target ranging method based on single-photon frequency up-conversion detection is proposed, which combines time-correlated single-photon counting and dual-comb asynchronous optical sampling. By introducing a silicon-based single-photon avalanche photodetector with photon-level responsivity, the low signal-to-noise ratio problem caused by the low frequency conversion efficiency in the intensity cross-correlation process is overcome, and fast, high-precision absolute ranging is achieved with a large range in ambient illumination conditions and weak echo at the single-photon level. Additionally, it has a high detection sensitivity, precision, and robustness for noncooperative targets with different roughness values at different incidence angles and different acquisition times, as well as the capacity to resolve multiple targets. Specifically, for a positive aluminum oxide plate, the standard deviation of 20 measurements is better than 1.5 μm, and the linearity is within 2 μm. Furthermore, the proposed method has potential application prospects in the fabrication of single-photon LiDAR and three-dimensional profiling measurement with micrometer precision.