为解决激光二极管阵列侧泵浦激光板条引起的热效应问题,通过对侧泵浦板条温度场与热形变场分布的解析研究以及对激光二极管阵列侧泵浦激光板条工作状态的分析,建立了符合实际情况的热模型,提出了求解Poisson方程的新方法,得到了侧泵浦板条温度场与热形变场的一般解析表达式。以Nd:YAG板条为例,分析了侧泵浦Nd:YAG板条温度场、热形变场的分布情况。并结合全固态激光器的设计需要,定量研究了激光二极管阵列取不同泵浦功率与不同泵浦光斑时Nd:YAG板条的温度场分布情况。计算结果表明:使用输出功率为30 W的激光二极管阵列侧面泵浦Nd:YAG板条,若耦合到板条侧面的高斯光斑半径为150 μm、板条钕离子掺杂质量分数为1.0%时,板条泵浦面具有102.3 ℃的最高温升,泵浦面与通光端面产生1.54 μm和2.66 μm的最大热形变量。激光板条温度场解析方法解决了使用数值分析法造成研究精确度不高的问题,该方法还可以应用到激光系统的其他热问题研究中,为减弱激光系统中的热问题提供理论依据。

In order to solve the thermal effect problem of diode bar side-pumped laser slab,a temperature modeling of laser slab according to the practical situation was established based on analysing on the temperature field and thermal distortion field of diode bar side-pumped laser slab and discussing on its working characteristics.A novel solution of the Possion equation was established and the general analytical solutions of temperature field and thermal distortion field of laser slab were obtained.Then,by taking the Nd∶YAG slab as a model,the distributions of temperature field and thermal distortion field were analyzed.And the temperature fields of Nd:YAG slab under different pump powers and coupled radii were quantitative studied by considering on design requirements of all-solid-state lasers.Computational results indicate that when the YAG doped with a mass percent of 1.0% of Nd-ion is side-pumped by a diode bar with output power of 30 W,the Gaussian spot radius coupled on the side-face of laser slab is 150 μm,and the slab can get a maximum temperature rise of 102.3 ℃,and the maximum thermal distortions of 1.54 μm and 2.66 μm on the side-face and the end-face,respectively.This analytical solution of temperature field can improve the low precision of the numerical analysis method in research of diode laser side-pumped laser slab interior temperature field,and also can be used to analyze other thermal problems in laser systems.