Experimental Study On Passively Q-switched All Solid State Optical Parametric Oscillators

Eye-safe and intermediate infrared laser can be obtained by all-solid-state Optical Parametric Oscillators, which has important application in some fields such as laser ranging, medical treatment and military.In this paper, the theory of quasi-phase-matching was explained from the point of three-wave interaction and operational characteristics of OPO was analyzed. Based on the rate equations of passively Q-switched, the rate equations of IOPO system under the ESA effects were studied, the expression of OPO effective cross-section was deduced; The period-tunable characteristics of PPMgLN was discussed.The PPMgLN-IOPO experimental system of LDA end-pumped Nd:YVO4/Cr:YAG passively Q-switched laser was constructed. Wide spectral tuning range were obtained, the signal wavelength was from 1.4 tol.64μm and the idle wavelength was from 3.03 to 4.49um. When the pump power was 10.2W, the pulse width of signal light was 14ns, the output power of 3.13μm idle light was up to 250.4mW, conversion efficiency of intermediate infrared laser was 2.54%. At the same time, the output characteristics of PPMgLN-IOPO experimental system of LDA end-pump Nd:YVO4/Cr:YAG passively Q-switched were explained.