LD端面泵浦变热传导系数Nd:YAG晶棒温场特性  

Temperature field characteristics analysis of Nd:YAG rod with variable thermal-conductivity coefficient by LD end-pump

作　　者：齐兵[1] 李隆[1,2] 甘安生[1,2] 王良甚[1,2] 史彭[1,2] 

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》2012年第5期1174-1179,共6页Infrared and Laser Engineering

基　　金：西安市科技局创新支撑项目(CXY1015(6));陕西省工业攻关资助项目(2008K05-15)

摘　　要：为了解决激光二极管泵浦激光晶体产生的热效应问题,对激光晶体内的温升进行了解析分析与定量计算。通过对激光二极管端面泵浦激光晶体工作特点的分析,建立了符合实际工作情况的热模型。考虑到晶体材料热传导系数受其宏观温度变化的影响,应用常数变易法以及特征函数法得到了变热传导系数Nd:YAG晶体棒在端面泵浦情况下温度场的一般表达式。定量计算了激光二极管超高斯分布泵浦光阶次、泵浦功率、光斑尺寸以及晶棒半径对其温度场分布的影响。研究结果表明:使用输出功率为60 W的激光二极管端面泵浦掺钕离子质量分数1.0%的Nd:YAG晶棒,若耦合入射的3阶超高斯光束泵浦光斑半径为400μm,晶棒半径为1.5 mm,长度为8 mm时,Nd:YAG棒内最大温升为343.9℃;而将其热导率视为定值时,晶体的最大温升只有222.7℃。研究结果为正确计算Nd:YAG晶体温度场分布提供了方法,并为提高全固态Nd:YAG激光器性能提供了理论依据。In order to solve thermal effects of Nd：YAG rod end-pumped by diode laser, the temperature raise of Nd：YAG rod were analytically investigated and quantitatively calculated. By analyzing the working characteristics of laser crystal end-pumped by diode laser, a thermal model according to actual situation was established. Considering the thermal-conductivity coefficient of laser crystal would be changed with its macro-temperature, a general temperature field expression of Nd＇YAG rod with variable thermal-conductivity coefficient by diode laser end-pumped was obtained by the methods of constant variation and eigen-function. Meanwhile, the temperature field influences of the super-Gaussian beam with different orders, pump power, pump spot size and the radius of laser rods were quantitatively calculated. The results show that when the 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 p^m, the maximal temperature raise of Nd：YAG rod with the 1.5 mm radius and 8.0 mm length is 343.9 ~C. However, when the value of thermal conductivity is assumed as a definite value, the maximal temperature raise of crystal is 222.7 °C. The results can provide the correct calculation method of the temperature distribution of Nd：YAG rod and play theoretically instructive effects at improving the performance of all-solid-state Nd：YAG lasers.

关 键 词：热效应 激光器 Nd:YAG棒 热传导系数 温度场分布 

分 类 号：TN248.1[电子电信—物理电子学]