QLM is revolutionising gas sensing in the oil & gas industry by developing compact, high-sensitivity, low-power Tuneable Diode Lidar (TDLidar) gas detection and imaging systems based on infrared single-photon detection. Using technology based on research developed at the University of Bristol, QLM meets the needs of natural gas producers, distributors and service providers with fast, accurate and low-cost gas leak identification and monitoring. QLM is also developing some of the world's most sensitive remote gas detectors for environmental monitoring. The sensors provide 3D mapping of methane, a key greenhouse gas, and can also be adapted for different gas species.