圆棒Nd:glass热容激光器的热过程半解析分析

建立了基于Nd:glass热容激光器的热传导模型,利用半解析热分析理论,对于给定的边界条件和初始条件,分别求解出泵浦阶段和冷却阶段时圆棒Nd:glass晶体的Poisson方程的解,得出圆棒Nd:glass晶体的温度场、形变场以及由端面热形变引起的热焦距、附加光程差的计算公式。研究结果表明:当泵浦总功率为2kW,4阶超高斯分布LD对Nd:glass晶体泵浦4s时,获得泵浦阶段圆棒Nd:glass晶体最高温升67.10℃,最大形变量为35.45μm,中心处附加光程差为5.677μm。冷却阶段圆棒Nd:glass晶体冷却800 s后中心最大热形变量为0.943μm。为优化热容激光器提供了理论依据。

Semianalytical analysis of the thermal process of a heat capacity Nd:glass laser rod

Based on the thermal conduction model of Nd:glass laser of which the boundary and initial conditions were given,the temperature field,distortion field,the thermal focal length and the additional optical path difference caused by thermal distortion in the end surface in the Nd:glass rod were obtained by solving the Poisson equation of the Nd:glass rod in the pumping and cooling stages using semi-analytical thermal analysis theory.The results show that,when the Nd:glass rod is pumped for 4 s by a LD with a total power of 2 kW and pump light of fourth rank of super-Gaussian distribution,in the pumping stage the maximum temperature rise is 67.10 ℃,the maximum thermal distortion is 35.45 μm,and the additional optical path difference in the center is 5.677 μm.After the Nd:glass being cooled for 800 s in the cooling stage,the maximum thermal distortion is 0.943 μm.The results can provide theoretical basis for the optimized design of the heat capacity lasers.