Watt-level long-wave infrared CdSe pulsed-nanosecond optical parametric oscillator

Abstract In this paper, using two cadmium selenide (CdSe) crystals, we have demonstrated signal-resonant pulsed-nanosecond optical parametric oscillators (OPOs) in linear and rectangular ring cavity designs with output powers of up to 1.03 W at 10.15 μm (idler) and 1.18 W at 11 μm (idler) were obtained, respectively. A Q-switched Ho:YAG laser at 2.09 μm with a pulse repetition frequency of 1 kHz was used as the OPO pump source. At the maximum output power level of the idler at 10.15 μm, the corresponding slope efficiency and optical conversion efficiency were 5.22% and 2.33%, respectively, with a spatial beam quality of M2