二极管阵列侧面泵浦固体激光介质的光场分布

Pump uniformity study of solid state laser rods dircet side-pumped by laser diode

研究LD阵列侧面泵浦Nd:YAG激光器泵浦光场的分布特点。首先,在已建立的二极管单bar单侧面泵浦YAG晶体泵浦光场分布数值模型的基础上,进一步建立了适用于激光二极管阵列多侧面泵浦YAG晶体的泵浦光场分布数值模型。然后,根据所建模型,采用光线追迹的方法,借助Matlab编程模拟了单侧面、二侧面、三侧面、五侧面泵浦方式的泵浦光分布特点,分析了系统参数:介质半径、介质吸收系数、光束光腰半径、泵浦距离、二极管bar间距、介质表面粗糙程度对泵浦光分布特性的影响,总结出了一般规律。可为二极管泵浦固体激光器的结构设计和实验研究提供理论参考。在理论分析的基础上,进行了单侧面、二侧面泵浦方式的二极管阵列直接侧面泵浦固体激光器的实验研究。实验结果与理论分析结果基本相符,验证了所建数值模型的正确性。该数值模型的特点是:采用光线追迹方法;适用于漫反射表面工作物质;适用于多种侧面直接泵浦方式,具有可扩充性。

The characteristics of the pumping light distribution in Nd：YAG rod direct side-pumped by diode bars are studied in this paper.Firstly, an approximation but simple analytical solution to the radical distribution of deposited energy in a diode-ba-pumped laser rod is provided based on the characteristics of the Gauss beam and the output of diode laser. Furthermore, the theoretical models of pumping energy distribution in a diode-array-pumped laser rod are made.Then, how the parameters （size of the medium, absorption coefficient of the medium, distance between the laser diodes, and so on） affect the homogeneity of pumping energy distribution in the medium is achieved according to the numerical simulation, and a set of general rules is summarized, and that can offer reference to experimental investigtion.The distribution of pumping light in Nd：YAG rod is measured with CCD camera which is in good agreement with computer numerical simulation. The experiment results are analyzed and discussed. The comparison results illustrate that the theoretical models are correct.Using ray trace algorithm, applying to the diffuse reflection surface medium and applying to multifarious direct side-pumping are the characteristics of the theoretical model.