激光二极管阵列端面抽运复合棒状激光器热效应的有限元法分析

建立了激光二极管阵列(LDA)端面抽运棒状激光介质的数值模型.考虑到介质与空气的对流换热和介质的热力学参数随温度的变化,根据经典热传导方程和热弹性方程,运用有限元法得出了复合棒状介质和未复合棒状介质内瞬态温度、热应力和应变的时空分布,分析了温度、热应力和应变随抽运功率、换热系数和时间的变化规律.结果表明,复合棒的最高温度、最大张应力和最大轴向应变的位置与未复合棒不同,并且数值分别为未复合棒的73%,60%和33%.由此可知,利用复合棒可极大地减小热效应的影响.理论分析结果可为LDA抽运固体激光器的结构优化设计和实验研究提供理论参考.

Analysis on thermal effect of laser-diode array end-pumped composite rod laser by finite element method

A numerical model of the rod laser medium pumped by laser-diode array (LDA) end is set up. Considering the influence of temperature correlation of the thermodynamic parameters of the material and heat transfer coefficient between air and medium, using the thermal conduction equations and the thermal-elastic equations, the transient distributions of temperature and thermal stress and strain in the composite rod medium and un-composite rod medium are calculated by the finite element analysis method. The effects of pump power and heat transfer coefficient and time on transient distributions of temperature and thermal stress and strain in the medium are analyzed. The results indicate that the positions of maximal temperature maximal tensile stress and maximal axial strain of the composite rod are different from those of the un-composite rod. And the maximal temperature, maximal tensile stress and maximal axial strain of the composite rod are respectively 73 per cent, 60 per cemt, and 33 per cent of the corresponding values of the un-composite rod. It is obvious that the thermal effect of the composite rod is greatly reduced. The theoretical results provide theoretical reference for the design of solid laser pumped by LDA and experimental study.