LD端面抽运激光介质热效应的有限元分析

Finite element analysis of thermal effect of LD endpumped laser medium

针对激光介质的通光面为方形、抽运光为高斯光束的情况,以Nd∶YAG激光介质为例,用ANSYS有限元软件模拟了激光介质的热效应,精确地给出了激光介质中各点的温度和温度分布。分别对提高介质侧面对流换热系数、降低冷却液温度、抽运端面水冷这3种情况下的温度场进行了模拟。结果表明,通过提高晶体侧面的热对流换热系数和降低冷却液温度,几乎不能降低激光介质的热效应,而通过抽运端面水冷,可有效地降低激光介质的热效应。

For the case of square end faces of the medium,focused Gaussian beam pumping,temperature field of laser medium end-pumped by laser diode（LD） has been studied by using finite element methods. The temperature and its distribution in the medium, such as Nd：YAG, are determined. At last the temperature field at the condition of improving the convective heat coefficient of medium＇s surface, reducing the coolant temperature or cooling the pumped face of rod is simulated. The results indicate thatit hardly fall the thermal effects by imoroving the convective heat coefficient of medium＇s surface and reducing the coolant temperature ,but it can reduce the thermal effects virtually by cooling the pumped face of rod.