谐振腔损耗测量系统的光学模式匹配研究

发布时间：2018-05-26 23:18

本文选题：谐振腔 + 模式　；参考：《西安工业大学》2015年硕士论文

【摘要】：光学谐振腔是激光器的组成部分之一,合理的谐振腔结构设计,可以改变激光器输出光束的特性。低损耗是评价谐振腔结构设计优良的标准之一,而损耗的大小与谐振腔中的光场模式是相关的,因此,本文通过分析谐振腔中的光场模式来获得谐振腔的损耗,从而为谐振腔结构的改善提供理论依据。本文在谐振腔损耗测量系统的基础上,深入研究了外光路与内光路的光斑匹配以及谐振腔内的模式分布。在光斑匹配中,分析了不同曲率半径的球面镜、不同位置时球面镜所引起的象散问题,给出了如何消除象散的方法；对于谐振腔内的模式的研究,本文首先分析了直型谐振腔,利用MATLAB软件,通过仿真得到了谐振腔内优先起振模式的三维分布图,计算了各阶模式的光斑半径值、相移值、损耗值、模式数目等；通过改变谐振腔的结构,分析了腔长、球面镜尺寸、球面镜曲率半径对腔内模式的影响,研究显示三者对腔内模式分布均会产生影响,但腔长和球面镜尺寸对模式的影响更加显著；在此基础上分析了带有光阑的直型腔,通过改变光阑尺寸的大小、位置,发现谐振腔中的损耗值、光斑半径值及模式数目均被影响,并与直型谐振腔进行了对比,结果显示加入光阑后,谐振腔内的高阶模式被抑制了,有效减少了腔内的模式；其次,利用等价的方法将环形腔结构等价为直型腔结构,研究了环形腔内的模式。最后,利用Matlab软件,设计了完整的程序,设计的界面程序使操作和仿真结果显示直观方便。研究结果表明,选取合适的球面镜参数及球面镜的位置,可以降低光学元件所引起的象散；为了使腔内有较少的模式,加入光阑可以起到抑制高阶模式的作用；对于结构较为复杂的环形腔模式研究可以采用等价的方法。
[Abstract]:Optical resonator is one of the components of laser. Reasonable design of resonator structure can change the characteristics of laser output beam. Low loss is one of the best criteria for evaluating the structural design of resonator, and the loss is related to the mode of light field in resonator. Therefore, the loss of resonator is obtained by analyzing the mode of light field in resonator. Thus, the theoretical basis for the improvement of the resonator structure is provided. On the basis of the resonant cavity loss measurement system, the spot matching between the external and inner optical paths and the mode distribution in the resonator are studied in this paper. In spot matching, the astigmatic problem caused by spherical mirror with different curvature radius and different position is analyzed, and the method of eliminating astigmatism is given. By using MATLAB software, the three-dimensional distribution diagram of the priority starting mode in resonator is obtained by simulation, and the radius value of light spot, phase shift value, loss value, number of modes of each order mode are calculated, and the cavity length is analyzed by changing the structure of resonator. The influence of spherical mirror size and radius of curvature of spherical mirror on the mode of cavity is studied. The results show that all of them have an effect on the mode distribution, but the length of cavity and the size of spherical mirror have more significant influence on the mode. By changing the size and position of the diaphragm, it is found that the loss value, the radius of the spot and the number of modes are all affected in the resonator, and compared with the straight resonator. The results show that the higher-order mode in the resonator is suppressed after the aperture is added, which effectively reduces the mode in the cavity. Secondly, the structure of the ring cavity is equivalent to the structure of the straight cavity by the equivalent method, and the mode in the ring cavity is studied. Finally, a complete program is designed by using Matlab software, and the interface program is designed to make the operation and simulation results display intuitively and conveniently. The results show that the astigmatism caused by optical elements can be reduced by choosing proper spherical mirror parameters and the position of the spherical mirror, and in order to make the cavity have fewer modes, the aperture can restrain the higher-order mode. The equivalent method can be used to study the ring cavity model with complicated structure.
【学位授予单位】：西安工业大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TN248

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