Research On Compound Crystal Short Pulse 532 Nm Laser

All solide state green lasers have been applied to many fields because of the small cavity, high efficiency and other advantages. This article begins with many superiorities of all solide state laser. Firstly, we summary the develop and application system of all solide state laser, then analyze every structure in the laser cavity detailedly. Therefore the complexed crystal of Nd:YAG/Cr4+:YAG, nonlinear crystal of KTP and output mirror with diffirent transmittance are optimized and experimental data are analyzed.In the aspect of theory analysis, based on the complexed crystal of Nd:YAG/CR4+:YAG, we introduce the theory of Q-switched and the advantages of choosing passively Q-switched, and discuss the saturation absorption characteristics of Q-switched crystal Cr4+:YAG and the advantages of complexed crystal compared with ordinary Q-switched lasers, then test and verify the experiment based on the rate equation of passively Q-switched. We deduce the coupling wave equation and theory of frequency doubling and nonlinear frequency conversion, and analyse physico-chemical property and optical performance of nonlinear crystal. The end, we choose the optimised KTP crystal.In the aspect of experiment, LD with output power of 5W is used as pumping source for complexed crystal laser and TEC is used for cooling, compexed crystal Nd:YAG/Cr4+:YAG as laser medium and Q-switch. TypeⅡphase matching KTP is used as frequency doubling crystal. when the pumped power is 4.8W, 532 nm pulse green laser is achieved which average power is 120 mW. The repetition rate is 17.55 k Hz and pulse width is 12 ns, the power of 1064 nm is 950 mW. The optical conversion efficiency of pumped light to fundamental frequency light is 19.7% and pumped light to 532 nm green laser is 2.5%.