脉冲LD端面泵浦Nd:YAG晶体温场研究  

Temperature field of pulse LD end pumped Nd:YAG crystal

作　　者：支音[1] 李隆[1,2] 史彭[1,2] 屈子杰 甘安生[1] 

机构地区：[1]西安建筑科技大学理学院,陕西西安710055 [2]西安建筑科技大学应用物理研究所,陕西西安710055

出　　处：《红外与激光工程》2015年第2期491-496,共6页Infrared and Laser Engineering

基　　金：陕西省教育厅专项科研基金(11JK0532)

摘　　要：为解决脉冲激光二极管端面泵浦Nd:YAG晶体产生瞬态热效应的问题,对激光晶体内的温场分布进行了解析分析与定量计算。通过对脉冲激光二极管端面泵浦激光晶体工作特点分析,建立了端面绝热、周边恒温的晶体热模型,考虑到Nd:YAG晶体导热系数与其温度的函数关系,引入弦截法求解含时热传导方程,得出了变热传导系数方形Nd:YAG晶体时变温度场的一般解析表达式。定量分析了变热传导系数方形Nd:YAG晶体在不同超高斯阶次和光斑半径下内部温度场时变情况。计算结果表明:使用平均输出功率为60 W的脉冲激光二极管端面泵浦掺钕离子质量分数1.0%的Nd:YAG晶体,若入射的3阶超高斯光束泵浦光光斑半径为400μm,则晶体尺寸为4 mm×4 mm×8 mm的Nd:YAG晶体在达到准热平衡状态时的最高和最低温升分别为364 K和337 K。研究结果为正确计算Nd:YAG晶体温度场分布提供了方法,并对解决激光晶体热效应问题提供了理论依据。The temperature thermal model of crystal was built under the condition of thermal isolation of the end face and constant peripheral temperature, so as to calculate temperature field of pulse LD end-pumped Nd：YAG crystal. Based on the function of temperature of the laser crystal depending on the thermal conductivity, the thermal model of heat conduction equations were solved by methods of the secant method. The numerical values of the temperature field of the pulse LD end-pumped square cross section Nd：YAG crystal with variable thermal conductivity was obtained. Then the internal temperature field distribution was calculated under different of super-Gaussian beam with different orders and pump spot sizes. The results show that when the average output power of diode laser is 60 W, and the neodimium doped yttrium aluminum garnet with 1.0% neodymium-ion doped mass fraction, the third order super-Gaussian radius of incident light is 400 μm. When the transient temperature field of Nd：YAG crystal, which size in 4 mm ×4 mm ×8 mm, reaches thermal dynamic equilibrium state, the maximum and minimum temperatures are 364 K and 337 K respectively. The research methods and results can also be used to analyze other time-varying thermal problems in laser systems, and will play theoretically a directional role in solving thermal problems in laser systems.

关 键 词：激光器 瞬态热效应 ND:YAG晶体 变热传导系数 

分 类 号：TN248.1[电子电信—物理电子学]