Quasi-phase-matched optical parametric oscillator based on PPMgLN

Theoretical and experimental study is presented on grating period-tuned single-resonated quasi-phase-matched optical parametric oscillator in multi-grating periodically poled MgO-doped lithium niobate(PPMgLN) pumped by 1 064 nm laser. Theoretical analyses include grating period tuning, pump threshold and converting efficiency of PPMgLN SRO. The pump source is a acousto-optically Q-switched CW- diode- side- pumped Nd:YAG laser. The pump beam polarization matches the e→e+e interaction in PPMgLN, thus the maximum nonlinear coefficient (27.4 pm/V) is effective. When pump power is 8 W, an average output power of more than 1.6 W at 3.7 mm is obtained with a corresponding slope efficiency of more than 20%, and a tunable mid-infrared wavelength output from 2.7 to 4.8 mm is also obtained by gratin