为了达到野外使用要求,采用变反射率镜(VRM)非稳腔和折叠腔方式,研制了高光束质量的小型脉冲激光器。分析了VRM腔参数对输出激光束特性的影响,针对高光束质量输出要求,通过计算,选择出适合的谐振腔参数。为了实现小型化和免调整特性,采用角锥棱镜作为折叠棱镜,设计了腔内线偏振光振荡的角锥棱镜激光谐振腔。根据理论分析结果,进行了实验研究。结果显示,在氙灯抽运下注入电能32.4 J,实现重复频率(1-10 Hz)单脉冲能量输出,获得了高光束质量、高动静比的基模光斑。在3 Hz重复频率下,脉冲能量为320.2 mJ,脉宽8.3 ns,光束质量为1.27,Q开关效率为95.5%,电光转换效率为0.99%。

A Q-switched repetitive mini laser is developed by requirement of high beam-quality.The interrelations between the parameters of variable reflectivity mirror (VRM) and con-focal unstable resonator and their effects on laser intensity distributions are analyzed.A suit of resonator parameters is obtained to meet high beam-quality of outputting.In order to develop a mini adjust-free laser,a folded resonator is designed,where a cube corner prism is used as the folded mirror.Because linearly polarized light exists in the resonator,the laser can be run with an electro-optic Q-switch in a special polarization azimuth.Based on these theory analyses,an amount of experiments have been done.Using a xenon flash lamp with 32.4 J as the pump energy,single pulse laser output of high beam-quality and high dynamic to static ratio light spot is obtained,and its repetitive frequency is 1-10 Hz.When the laser works at the repetitive frequency of 3 Hz,an energy of 320.2 mJ,pulse width of 8.3 ns output beam is achieved,and its efficiency of the Q-switch is 95.5%,while the electro-optical efficiency is 0.99%.