4～5μm全固化可调谐激光实验研究

Experimentation of Tunable All-Solid-State Laser Producing4～5 μm Radiation

报道了采用KTP晶体和LiIO3晶体实现4～5μm可调谐激光输出的光参量振荡器（OPO）至差频产生器（DFG）的全同化结构和相应的实验结果。其中光参量振荡器的抽运源为倍频Nd：YAG激光，差频产生器的抽运源分别是上述光参量振荡器激光和Nd：YAG基频激光经KTP倍频晶体后剩余的1．064μm激光。实验中Nd：YAG基频脉冲激光脉宽12ns，单脉冲能量300mJ。观察到最大倍频效率达到66．7％，KTP参量量子转换效率达到50％，差频量子转换效率为1．5％，在4．45“μm得到了单脉冲100μJ的激光输出。差频光的调谐范围为4．1～4．5μm，发散角为垂直方向12mrad，水平方向4mrad。

An all-solid state LiIO3 difference frequency generator （DFG）, pumped by a singly resonant KTP optical parametric oscillator （OPO） pumped by the second harmonic of a pulsed Nd： YAG laser, which have a pulse width of 12 ns and pulse energy of 300 mJ, operating at 1. 064μm and the fundamental frequency Nd：YAG laser, is experimentally demonstrated and analyzed. The maximum frequency-doubling conversion efficiency is 66.7%; quantum conversion efficiency of KTP OPO is 50%; the quantum conversion efficiency of difference frequency generator is 1.50%, and 100 μJ energy of single pulse is achieved at 4.45μm wavelength. The frequency tuning range is 4.1-4.5 μm. The beam divergence is 12 mrad in vertical direction and 4 mrad in horizontal direction.