LD端面泵浦千赫兹多波长激光器

LD End-Pumped Kilohertz Multiwavelength Lasers

报道了一台用于大气探测激光雷达系统的LD脉冲端面泵浦Nd∶YAG激光晶体的腔外倍频千赫兹多波长激光器。采用紧凑介稳腔设计和电光调Q方式,获得具有高动静比的1064 nm基频光脉冲输出。腔外采用Ⅰ类相位匹配LBO晶体倍频,Ⅱ类相位匹配LBO晶体和频,实现了355 nm和频光输出,同时对355 nm和频光单脉冲能量的影响因素进行了理论分析和实验研究。当倍频转换效率为53%时,获得重复频率为1 kHz的三波长激光分束输出,对应的单脉冲能量分别为1.18 mJ@1064 nm、1.06 mJ@532 nm、0.73 mJ@355 nm;脉冲宽度分别为3.49 ns@1064 nm、3.42 ns@532 nm、3.02 ns@355 nm;光束质量因子分别为M_(x)^(2)=1.70、M_(y)^(2)=1.75@1064 nm,M_(x)^(2)=1.57、M_(y)^(2)=1.41@532 nm,M_(x)^(2)=1.51、M_(y)^(2)=1.38@355 nm。

This study describes an extra-cavity frequency-doubled kilohertz multiwavelength laser for an atmospheric detection lidar that uses an LD pulse end-pumped Nd∶YAG laser crystal.It adopts an electro-optic Qswitching technique and a compact metastable cavity design to achieve a high dynamic-to-static ratio of 1064-nm fundamental frequency optical pulse output.TypeⅠphase-matched LBO crystal frequency doubling and typeⅡphase-matched LBO crystal sum-frequency outside the cavity were used to produce 355-nm sum-frequency light.Additionally,the influence factor of 355-nm sum-frequency light pulse energy was theoretically and experimentally investigated.A three-wavelength laser beam splitting output with a repetition frequency of 1 kHz was obtained for a frequency doubling conversion efficiency of 53%.The corresponding single-pulse energy was 1.18 mJ at 1064 nm,1.06 mJ at 532 nm,and 0.73 mJ at 355 nm,and the pulse width was 3.49 ns at 1064 nm,3.42 ns at 532 nm,and 3.02 ns at 355 nm;and the beam quality factors were M_(x)^(2)=1.70,M_(y)^(2)=1.75 at 1064 nm,M_(x)^(2)=1.57,M_(y)^(2)=1.41 at 532 nm,and M_(x)^(2)=1.51,M_(y)^(2)=1.38 at 355 nm.