由于a轴切割Nd∶YVO4晶体的非对称性,使得激光二极管(LD)端面抽运Nd∶YVO4固体激光器不同于Nd∶YAG激光器,输出的激光经常产生非对称结果。用有限元法分析激光二极管端面抽运a轴切割Nd∶YVO4固体激光器的晶体热效应,包括温度分布、内部应力和产生的形变。分析结果表明端面抽运a轴切割Nd∶YVO4晶体产生了椭球热透镜效应。从结构方面和抽运方面提出了热透镜非对称性的平衡方法,实验验证了方法的可行性。

The asymmetry of a-cut Nd∶YVO4 leads to asymmetrical laser output from laser diode (LD) end-pumped Nd∶YVO4 solid state laser, which differs from Nd∶YAG laser. The finite element was applied to analyze the thermal effect of LD end-pumped a-cut Nd∶YVO4 crystal, including temperature distribution, internal stress and its deformation. The results indicate that the thermal lens of end-pumped a-cut Nd∶YVO4 crystal takes the ellipsoidal distribution. The method of balancing the asymmetry of thermal lens was put forward by the way of structure and pumping, and experimentally proved feasible.