提出了一种用于激光二极管端面抽运固体激光器(DPSSL)中晶体端面直接散热的新方案——在传统的侧壁散热基础上采用金刚石薄片对晶体的抽运面进行散热。使用有限元方法(FEM)分析了该方案的散热效果, 并与传统侧壁散热方案的散热效果作了比较, 结果表明, 使用晶体端面直接散热方案可以将集中于晶体端面的热量更为有效地抽出, 大幅度降低晶体抽运端面内的温差, 晶体温度最高点出现在晶体内部, 降低了晶体抽运端面热损伤概率, 显著减弱了晶体热效应; 在相同注入功率条件下实验测量了两种散热方式下的输出功率, 结果表明, 晶体端面直接散热方案可以有效抑制晶体热效应对于输出功率的不良影响, 该方案特别适合用于解决大功率端面抽运固体激光器的散热问题。

A new method of heat dissipation in a laser diode end-pumped solid-state laser is proposed, and the heat is dissipated from the pumped end with a piece of diamond disk clinging to the pumped end and from the side surface of the crystal rod. The finite element method (FEM) is used to analyze the effect of heat dissipation, and a comparison is made of the cooling effect of the new method with that of traditional method dissipating heat through the side surface of crystal rod. The results indicate that the heat concentrated in the pumped end of the crystal rod can be efficiently removed by the new method, which greatly decreases the temperature difference in the pumped end, and that the highest temperature point appears inside the gain medium, which lowers probability of break in the pumped end, and obviously reduces the thermal effects of the crystal rod. With the same power injected into the crystal rod, experiments are done to compare the output power of a laser diode end-pumped solid-state laser with the two different heat dissipation methods. The results show that the method of direct heat dissipation from the pumped end can sufficiently weaken the influence of thermal effect on the power output and this method is particularly suitable for solving the problem of heat dissipation in a high-power end-pumped solid-state laser.