激光二极管端面抽运Nd:GdYVO4晶体热效应分析及倍频研究

通过求解泊松热传导方程,得出了端面抽运下矩形截面Nd:GdYVO_4激光晶体内部温度场分布以及Nd: GdYVO_4激光晶体抽运端面达到热平衡后的热形变量。当抽运功率为12 W,抽运光斑半径w_p=320μm时,Nd: GdYVO_4激光晶体的热形变量为0．855μm。根据Nd:GdYVO_4晶体内部温度场分布和晶体抽运端面达到热平衡后的热形变量,进而计算出晶体热焦距随抽运功率的变化。通过ABCD矩阵进行了腔参数优化,选取了更有效压缩KTP上基模光斑半径的V腔进行腔内倍频实验。在抽运功率为6．71 W时Nd:GdYVO_4获得了1．73 W稳定倍频绿光输出,光-光转换效率达到25．8％,绿光非稳度为1．13％。

Characteristics of Laser Diode End-Pumped Laser Crystal on Thermal Effect and Second Harmonic Generation

Based on Possion equation, a thermal model of rectangle end-pumped Nd:GdYVO4 was bulit. The crystal temperature fields of Nd:GdYVO4 were distributed. Then the distortion on pump face was calculated. When the pumping power is 12 W, the radii of pump beam is wp=320 μm, the distortion of Nd:GdYVO4 is 0.855 μm. Based on the previous calculation, the focus of thermal lens changing with input power was calculated. Using ABCD matrix to optimize cavity parameters, V-shaped folded cavity which could compress the laser mode radii on KTP effectively was selected. With the pumped power of 6.71 W, an 1.73 W output power of stable frequency-doubled green light was achieved by V-shaped folded cavity, giving an optical-optical conversion efficiency of 25.8%, and green light non-stability Δ/=1.13%.