基于圆环达曼光栅整形的环形光抽运的Nd…YAG声光调Q涡旋光激光器

Acousto-Optically Q-Switched and Vortex Nd…YAG Laser by Using Circular Dammann Grating for Annular Pumping

研究了圆环达曼光栅(CDG)整形的环形光抽运的声光调Q Nd…YAG激光器。该激光器的腔体由激光晶体、声光调制器以及平面输出耦合镜组成。所用抽运源为光纤耦合808nm半导体激光器,其发射光经过CDG发生一级衍射,产生的环形光场强度分布用于端面抽运Nd…YAG激光晶体。实验获得了高光束质量、线偏振、且具有螺旋相位的主动调Q脉冲光输出。当吸收抽运功率为5.6 W、声光调制器工作频率为5kHz时,激光脉冲的平均功率为470mW,峰值功率达到588 W,脉冲宽度为160ns。

An acousto-optically Q-switched vortex Nd： YAG laser by annular pumping of circular Dammann grating （CDG） shaping is investigated. The cavity of the laser is composed of a laser crystal, an acousto-optical modulator and a planar output coupling mirror. The pump source is a fiber coupling semiconductor laser of 808 nm. The annular intensity distribution of pump light is formed by the first-order diffraction of a CDG with high diffraction efficiency, which is used to end pumped Nd： YAG laser crystal. The active Q-swith pulse laser is obtained with high optical, quality, linear polarization and spiral phase. The obtained power of laser pulse is 470 mW, the peak power of laser pulse reaches 588 W and pulse width is 160 ns, when the absorbed pump power is 5.6 W and the frequency of acousto-opticai modulator is 5 kHz.