激光二极管端泵平板Nd:GdVO_4晶体热效应

Thermal effect of laser diode end-pumped Nd:GdVO_4 crystal slab

以解析热分析理论为基础,建立了平板Nd:GdVO4激光晶体在激光二极管阵列端面抽运时的导热微分方程。通过对方程的求解,得到了Nd:GdVO4晶体内部温度场解析式和热透镜焦距随抽运光半径和功率变化的分布关系。温度场的数值模拟表明:当泵浦光功率P=30W、泵浦区域为1mm×1 mm时,晶体在x,y,z方向的最高相对温升分别为104 K、31 K和31.8 K;若令z=0和x=0,则xy和xz面处的温度场分布类似于倒鼻型,这两个面上最高相对温升均为104 K;若令x=0,则yz面上的温度场分布类似于波包,此面处最高的温升为31 K左右;热透镜焦距的数值模拟给出了热透镜效应随抽运光功率和泵浦光半径变化的趋势。此方法也可以应用于其他激光晶体的热问题研究中,为有效解决激光系统热问题提供了理论依据。

Based on the theory of thermal analysis,the heat conduction equation of Nd：GdVO4 crystal slab end-pumped by diode laser arrays was built.By solving the equation,the analytic expression of temperature field and thermal focal length distribution along with the change of radius and power of pump light were obtained.When geometry of pumping diodes corresponds to 1 mm×1 mm,and the power is about 30 W,temperature numerical simulation results show that the maximum temperature rise is 104 K,31 K,31.8 K along x,y and z direction,respectively.If making z=0 and y=0,the temperature field of surface xy and xz are similar to the inverted nose,and the maximum temperature rise is 104 K at the two surface.If making x=0,the temperature field of surface yz is similar to the wave packet,and the maximum temperature rise is about 31 K at this surface.The change trends of thermal focal length along with the change of radius and power of pump light were given by numerical simulation.This method can also be applied in the research on the other thermal problems of laser crystal and offer theoretical basis for solving the thermal problems in laser system effectively.