激光分布对抽运Nd∶YVO_4晶体热效应的影响  

Influence of laser distribution on thermal effect of Nd∶YVO_4 crystal

作　　者：史彭[1] 陈文[1] 李隆[1] 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

出　　处：《光学精密工程》2008年第2期197-201,共5页Optics and Precision Engineering

基　　金：陕西省教育厅专项科研资助项目(No.06JK251)

摘　　要：以解析各向异性分析理论为基础,研究了在矩形横截面Nd∶YVO4激光晶体受到超高斯分布LD端面抽运时,激光晶体的温度场分布和抽运面热形变分布。通过分析激光晶体工作特点,考虑了激光分布和激光光束半径变化,建立了符合激光晶体工作状态的热模型。利用各向异性介质热传导方程的一种新求解方法,得出了矩形截面Nd∶YVO4晶体的温度场、端面热形变场的通解表达式。研究结果表明:当使用输出功率为15 W的半导体激光器(超高斯阶次为1)从端面中心入射Nd∶YVO4晶体(晶体掺钕离子质量分数为0.5%)时,在抽运端面中心获得了243.8℃最高温升和1.99μm最大热形变量,与实验结果一致。这种方法可以应用到其它激光晶体热问题研究中,为有效解决激光系统热问题提供了理论依据。Based on the analytical theory of anisotropy, the thermal distortion and temperature field distributions of laser crystal were investigated when Nd ： YVO4 crystal with rectangular section was end-pumped by a laser beam of super-Gaussian distribution from a Laser Diode（LD）. By analyzing the working characteristics of the Nd ： YVO4 laser crystal, a thermal model accorded with the working state of the laser crystal was established considering the distribution and the radius change of laser beam. By using a kind of new solution to the thermal conduction equation of the anisotropic medium, the general solution expressions of temperature field and the thermal distortion field of Nd ： YVO4 crystal with rectangular section were obtained. The results show that a maximum temperature rise of 243.8 ℃ and a maximum thermal distortion of 1.99μm can be obtained in the center of the pump face when the Nd ： YVO4 laser crystal is pumped by a LD with an output power of 15 W from the center of end face （the weight percent of neodymium ion doped in the crystal is 0.5%）, which is in agreement with experimental results. Also the result shows that this method can also be applied to the research on the other thermal problems of laser crystal and can offer theoretical basis for effectively solving thethermal problems in laser system.

关 键 词：激光物理 ND:YVO4激光器 热分析 超高斯分布 矩形截面 各向异性 

分 类 号：TN244[电子电信—物理电子学]