Single-photon imaging over 200 km

TL;DR

This paper demonstrates a compact single-photon lidar system capable of 3D imaging over 200 km, using advanced optical devices and noise suppression techniques, enabling accurate imaging with minimal photons.

Contribution

The authors introduce a novel noise-suppression method and high-efficiency optical system that extend the operational range of single-photon lidar to over 200 km.

Findings

Achieved 3D imaging at 201.5 km range.

Enabled accurate imaging with as few as 0.44 photons per pixel.

Demonstrated potential for practical long-range lidar applications.

Abstract

Long-range active imaging has widespread applications in remote sensing and target recognition. Single-photon light detection and ranging (lidar) has been shown to have high sensitivity and temporal resolution. On the application front, however, the operating range of practical single-photon lidar systems is limited to about tens of kilometers over the Earth's atmosphere, mainly due to the weak echo signal mixed with high background noise. Here, we present a compact coaxial single-photon lidar system capable of realizing 3D imaging at up to 201.5 km. It is achieved by using high-efficiency optical devices for collection and detection, and what we believe is a new noise-suppression technique that is efficient for long-range applications. We show that photon-efficient computational algorithms enable accurate 3D imaging over hundreds of kilometers with as few as 0.44 signal photons per pixel. The results represent a significant step toward practical, low-power lidar over extra-long ranges.