激光二极管双端抽运高功率高光束质量Z型折叠腔Nd:YVO_4激光器

High Power High Beam Quality LD Dual-End-Pumped Z Folded Resonator Nd:YVO_4 Laser

在高功率激光二极管(LD)抽运条件下,固体增益介质的热透镜效应是优化激光谐振腔系统所必须考虑的重要因素之一。利用带尾纤耦合输出的激光二极管和整形聚焦透镜组组合抽运Nd:YVO4晶体,用稳腔法测量了激光晶体的等效热焦距。利用LAS-CAD软件模拟了三种热稳腔结构在所测等效热焦距下的模式分布,对LD双端抽运Nd:YVO4激光器Z字型谐振腔进行优化设计后,实验选定后腔镜曲率半径R1=300mm,输出镜曲率半径R2=100mm,腔长Ltotal=280mm,耦合输出镜透射率T=50%。当输入61W抽运功率时,激光最高输出功率达21.3W,光束质量因子M2<1.41,所得激光器输出结果与理论预期吻合得很好。

When operating at a high-power region,thermal lens effect of diode pump solid state laser is an important factor which must be considered to optimize the laser system.The Nd：YVO4 crystal is pumped by a fiber-coupled laser diode which is shaped and focused by a lens group.The focal length of thermal lens is measured by using stable cavity method.The mode distribution of three thermal stable resonators with the thermal focal length is simulated by LAS-CAD software.By using this results the LD dual-end-pumped Nd：YVO4 laser Z-folded resonator has been optimized,with total reflection mirror radius of curvature R1=300 mm,and output coupling mirror radius of curvature R2=100 mm,with length of the resonator Ltotal=280 mm,and transmisttance of the output coupling mirror T=50%.CW TEM00 mode output is 21.3 W when the pump power is 61 W,and beam quality factor M2 1.41.The experimental results on laser output characteristics are in good agreement with the theoretical ones.