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Published November 3, 2025 | Version Published
Journal Article Open

Mid-infrared high-resolution photon-counting LiDAR

Creators

  • 1. ROR icon University of Glasgow
  • 2. ROR icon Jet Propulsion Lab
  • 3. ROR icon École Polytechnique Fédérale de Lausanne
  • 4. ROR icon California Institute of Technology
  • 5. Sung Kyun Kwan University
  • 6. ROR icon University of Geneva

Abstract

Mid-infrared (MIR) detection at the single-photon limit has become increasingly accessible, enabling applications in free-space communications, industrial sensing, astronomy, and biomedicine. However, direct time-correlated single photon-counting in the MIR remains a significant challenge. Here, we demonstrate single-pixel scanning light detection and ranging (LiDAR) at 3500 nm wavelength with sub-millimeter depth resolution in the single-photon regime, enabled by a differential impedance-matched tungsten silicide (WSi) superconducting nanowire single-photon detector (SNSPD), optimized for MIR detection, and an optical parametric oscillator (OPO) laser source. The detector's exceptional timing performance is demonstrated by resolving sub-millimeter depth features of a target positioned 100 mm from the transceiver. In addition, we present the wavelength-dependent photoresponse and timing jitter of the device across a 1550–5438 nm wavelength range. The photon-counting MIR LiDAR system shown features extremely wide broadband operation, high timing performance, and single-photon sensitivity. This work demonstrates the potential of MIR time-correlated single photon-counting applications enabled by SNSPDs.

Copyright and License

Published by Optica Publishing Group under the terms of the Creative Commons Attribution 4.0 License.
Further distribution of this work must maintain attribution to the author(s) and the published article’s title,
journal citation, and DOI.

Acknowledgement

DK and RHH acknowledge the work of former group members in constructing and improving the TCSPC ranging setup and sourcing MIR components, in particular Nathan Gemmell, Mahmoud Ahtaiba, Vidur Raj, and Ewan N. MacKenzie. DK also thanks Devendra K. Namburi, Vikas, and Robert Lamb for manuscript feedback. RHH thanks Chromacity Ltd. for excellent technical support. DK thanks the EPSRC and SFI Centre for Doctoral Training in Photonic Integration for Advanced Data Storage (CDT-PIADS EP/S023321/1).

Funding

Engineering and Physical Sciences Research Council (EP/S026428/1, EP/T00097X/1); National Research Foundation of Korea; Jet Propulsion Laboratory (NASA—80NM0018D0004); Defense Sciences Office, DARPA.

Data Availability

Data underlying the results presented in this paper are available in the University of Glasgow Enlighten Research Data Repository [59].

Supplemental Material

See Supplement 1 for supporting content.

Files

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Additional details

Identifiers

PMID
41414068

Related works

Describes
Journal Article: 41414068 (PMID)
Is supplemented by
Supplemental Material: 10.6084/m9.figshare.30342106 (DOI)
Dataset: 10.5525/gla.researchdata.2070 (DOI)

Funding

Engineering and Physical Sciences Research Council
EP/S026428/1
Engineering and Physical Sciences Research Council
EP/T00097X/1
National Research Foundation of Korea
Jet Propulsion Laboratory
80NM0018D0004
United States Department of Defense

Dates

Submitted
2025-08-21
Accepted
2025-10-10
Available
2025-10-20
Published online

Caltech Custom Metadata

Caltech groups
Division of Engineering and Applied Science (EAS)
Publication Status
Published