Remote gas leak detection using a portable mini-Lidar based on a doubly-resonant OPO

The laser transmitter is one of the key elements in a Lidar system. It has to produce a high-peak-power, single longitudinal mode (SLM) radiation, that can be tuned to the absorption lines of the species of interest, with a high beam quality. To fulfil such requirements, we have developed a compact semi-monolithic entangled cavity doubly resonant OPO (ECOPO) to reach SLM operation. Thanks to its low oscillation threshold (less than 2 μJ), the ECOPO is pumped by use of a microchip lasers, allowing the development of very compact instruments. Here we make use of the performances of this laser transmitter to develop a portable 3.8-4.3 μm range Lidar system for remote gas leak detection.