Few-photon imaging at 1550 nm using a low-timing-jitter superconducting nanowire single-photon detector.

Hui Zhou,Junjie Wu,Zhen Wang,Sijin Chen,Xiaoming Xie,Weijun Zhang,Lixing You,Yuhao He

doi:10.1364/oe.23.014603

Abstract

We demonstrated a laser depth imaging system based on the time-correlated single-photon counting technique, which was incorporated with a low-jitter superconducting nanowire single-photon detector (SNSPD), operated at the wavelength of 1550 nm. A sub-picosecond time-bin width was chosen for photon counting, resulting in a discrete noise of less than one/two counts for each time bin under indoor/outdoor daylight conditions, with a collection time of 50 ms. Because of the low-jitter SNSPD, the target signal histogram was significantly distinguishable, even for a fairly low retro-reflected photon flux. The depth information was determined directly by the highest bin counts, instead of using any data fitting combined with complex algorithms. Millimeter resolution depth imaging of a low-signature object was obtained, and more accurate data than that produced by the traditional Gaussian fitting method was generated. Combined with the intensity of the return photons, three-dimensional reconstruction overlaid with reflectivity data was realized.

Highlights

Light detection and ranging (LIDAR) is a remote sensing technology that measures distance by illuminating a target with a laser and analyzing the time-of-flight (TOF) of the reflected light
Combined with advanced time-correlated single-photon counting (TCSPC) techniques, LIDAR is sensitive to ultra-low levels of light and exhibits excellent depth resolution, which are determined by the detection efficiency (DE) and the timing jitter (TJ) of the optical receivers
We demonstrated a TCSPC depth imager operated at a wavelength of 1550 nm that incorporated a low-TJ superconducting nanowire single-photon detector (SNSPD)

Summary

Introduction

Light detection and ranging (LIDAR) is a remote sensing technology that measures distance by illuminating a target with a laser and analyzing the time-of-flight (TOF) of the reflected light This method is used to make high-resolution maps for many applications, including remote sensing, terrain mapping, and space debris tracking [1, 2]. Infrared depth imaging based on the TCSPC technique usually required hundreds of detected photons per pixel to obtain accurate information about the range and reflectivity, as the reported imaging system used a relatively noisy SPD with a high TJ in the receiver. Because of the low-TJ SNSPD and sub-picosecond time bin, the depth information was determined directly by the highest bin counts, which produced more accurate data than the traditional Gaussian fitting method for the low-signature target. Combined with the intensities of the return photons, the indoor and outdoor depth imaging overlaid with reflectivity data for a target with a stand-off distance of 2.5 m were demonstrated

Experimental setup and results

Findings

Conclusion