High-power mid-infrared tunable optical parametric oscillator based on 3-mm-thick PPMgCLN

The experimental results of a high-power tunable mid-IR laser are presented. The optical parametric oscillator (OPO) with a 3-mm-thick PPMgCLN crystal was pumped by a 1.064 mu m pulse laser. When the pump power of the 1.064 mu m laser was 151 W at 10 kHz, and the operating temperature of the PPMgCLN with 5% MgO doping was 100A degrees C, average output power of 23.7 W at 3.91 mu m was obtained with a slope efficiency of 18.2% for the idler resonant OPO. The variation of the 3.91 mu m output power was about +/- 4% in 10 min continuous operation. The beam quality factor M (2) was less than 2.6. The average output power of 27.4 W at 3.91 mu m was also obtained with 151 W pump power and the slope efficiency of 20.9% for the signal resonant OPO by changing the coating parameters of the OPO cavity mirrors. The mid-IR wavelength tunability of 3.7-4.0 mu m can be achieved by adjusting the temperature of a 29 mu m period PPMgCLN crystal from 200 to 30A degrees C.