Description
Hydrogen is attracting increasing interest as a clean energy carrier, driving demand for sensitive remote sensing technologies for leak detection and monitoring. More broadly, remote gas sensing is important for environmental, industrial, and safety applications. Raman LiDAR provides a selective and spatially resolved approach based on the characteristic Raman signatures of different molecular species. We present a numerical model of a time-correlated single-photon counting (TCSPC) Raman LiDAR system for remote gas detection. Based on the photon-counting form of the LiDAR equation, the model incorporates Raman scattering, optical overlap, detector response, detector dark counts, and crosstalk from Rayleigh scattering and adjacent Raman channels. It uses Poisson statistics as the basis for a Monte-Carlo approach to single-photon counting. The model successfully reproduces experimental measurements obtained from a TCSPC Raman LiDAR system, which employs a 355 nm pulsed laser, narrowband optical filtering, and single-photon detectors. This system has demonstrated a hydrogen limit of detection (LOD) of 137 ppm at a stand-off distance of 11 m. The validated model provides insight into the factors governing system performance and serves as a practical tool for the analysis, design, optimisation, and performance prediction of future field-deployable Raman LiDAR systems. This work demonstrates the value of physics-based numerical modelling in advancing TCSPC Raman LiDAR as a photonic sensing technology for selective and spatially resolved remote gas detection.
| I am the presenting author | Yes |
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