A novel 2 µm laser source for CO2 DIAL

Laser specifications for a spaceborne sensitive measurement of CO₂, by differential absorption LIDAR (DIAL) at 2.05 mum, have been derived in terms of output energy, frequency stability and beam quality. To achieve such operation, single longitudinal mode (SLM) operation and fine frequency control is needed. In previous work, the authors have developed an optical parametric oscillator based set-up for the detection of species (CO₂, CH₄, N₂O) with very low oscillation threshold. In this work, the range of operation of the previous device was extended to 2 mum range. It was demonstrated that using a type II PPLN based doubly resonant optical parametric oscillator (DROPO) in a master oscillator power amplifier (MOPA) configuration, energy levels in the tens of mJ range can be obtained, while maintaining both high spectral and spatial performances. High efficiency and high beam quality performances have been demonstrated recently in OPO/OPA configurations.