Single-photon imaging over 200  km

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.

Robust and Guided Bayesian Reconstruction of Single-Photon 3D Lidar Data: Application to Multispectral and Underwater Imaging

“…The parameters of x are independent allowing parallel updating of x n , ∀n. It is clear from (12) that the conditional distribution of x results from (9). Minimizing the negative-log of the conditional distribution reduces tô…”

“…Set conv= 1 if the convergence criteria are satisfied 17: end while 18: Output: 19: x, M , , Ψ of D is obtained by combining the likelihood in (8), and the prior in (9). Straightforward computations show that the update d…”

“…This paper focuses on some of them and provides a principled statistical-based solution to improve performance. Such challenges include the photon sparse regime [4]- [6] often observed for long-range imaging [7]- [9] or rapid imaging based on short acquisition times [10], [11] or adaptive imaging [12], [13]. Lidar is also sensitive to the observation environment when imaging in bright daylight conditions [14], and through obscurants or turbid media, such as underwater [11], [15], or through fog, rain [1], [16].…”

Single-Pixel Photon-Counting Imaging Based on Dual-Comb Interferometry

“…The development of single-photon detectors has revolutionized photon-counting laser ranging and imaging in speed and sensitivity [ 1 , 2 , 3 , 4 , 5 , 6 , 7 , 8 , 9 , 10 ]. Recently, there has also been interest in new methods that leverage the dual-comb target-encoded spectrum to perform imaging using a single-pixel detector [ 11 , 12 , 13 , 14 , 15 , 16 ].…”

“…Up to now, this method has only been applied using powers of the order of milliwatts to microwatts, which does not reach a photon-counting level [ 11 , 13 , 15 , 16 ]. However, to extend this method to more application scenarios such as remote imaging or sensitive biological tissue imaging, a dilemma will be encountered when the light signal reaches a photon-counting level [ 5 , 10 ]. To solve this problem, we come up with the idea to integrate the dual-comb imaging with a time-correlated single-photon counting technique which may provide the possibility to achieve both high resolution and high detection sensitivity in a dual-comb target-encoded imaging system for weak-light applications.…”