阐述了3～4 μm KTA光参量振荡器(OPO)研究的背景和意义,对目前国内外研究现状和发展趋势进行了分析。对KTA-OPO的相位匹配方式、温度调谐特性以及腔形进行了理论计算分析。同时对KTA-OPO参量设计中应考虑的一些问题如KTA晶体的最佳长度,抽运功率的影响,OPO腔镜的镀膜,OPO谐振腔的结构和腔长、抽运源和OPO之间的模式匹配等进行了讨论。所设计的3～4 μm KTA-OPO,其重复频率为1～40 Hz,脉宽<20 ns,单脉冲能量>30 mJ。

The background and the meaning of studying on 3～4 μm KTiOAsO4 (KTA) optical parametric oscillator (OPO) were clarified. The researching status at present and the developing direction in the future of the KTA OPO were introduced too. The phase-matching mode, the temperature tuning characteristic and the structure of OPO cavity were calculated and theoretically analyzed. At the same time, some problems which should be considered, such as the best length of the KTA crystal, the effect of pumping power, the coating of the OPO cavity mirror, the structure and cavity length of the OPO, the mode matching between the pump source and OPO, were discussed. The designed 3～4 μm KTA OPO pocessed the repeating frequency of 1～40 Hz, the pulse-width less than 20 ns and the single pulse energy more than 30 mJ.