Singly-resonant pulsed optical parametric oscillator based on orientation-patterned gallium phosphide

摘要

We report a pulsed singly-resonant optical parametric oscillator (OPO) based on the new nonlinear crystal, orientation-patterned gallium phosphide (OP-GaP). Pumped by a Q-switched Nd:YAG laser at 1064 nm, and using a 40-mm-long OP-GaP crystal with a single grating period of Lambda = 16 mu m, the OPO generates signal and idler output across 1.6-1.7 mu m and 2.8-3.1 mu m, respectively, under temperature tuning. For an average pump power of 4.8 W at 50 kHz pulse repetition rate, mid-infrared idler powers of up to similar to 20 mW have been obtained at 2966 nm with high output stability. For pump pulses of similar to 13 ns duration, the OPO generates similar to 6 ns output signal pulses. From temperature-dependent wavelength tuning measurements at two different pump powers of 4.2 W and 1.2 W, a discrepancy of 11-17 degrees C in the internal crystal temperature is estimated, implying that the OP-GaP sample suffers from increasing thermal effects at higher pump powers due to absorption. (C) 2018 Optical Society of America