猫眼谐振腔氦氖激光器理论分析

猫眼逆向器作为谐振腔镜与一个凹面镜构成猫眼激光谐振腔.精确计算了三种猫眼逆向器(即理想猫眼逆向器和两种存在误差的猫眼逆向器)的逆向平行反射性，并对应用这三种猫眼逆向器的谐振腔中高斯光束的各项参数进行了深入分析，得出结论：对于高斯光束，凸透镜的焦距、凹面镜曲率半径、凸透镜与凹面镜间距三者相等的猫眼逆向器为理想逆向器，其逆向平行反射性最好，此时猫眼谐振腔处于理想状态，基模模体积最大，远场发散角最小，稳定性最好；在猫眼谐振腔的设计中，要尽量减小猫眼逆向器中凸透镜的焦距，增大凹面输出镜的曲率半径；猫眼逆向器存在误差时谐振腔的各项性能将受到影响.为猫眼谐振腔激光器的设计提供了理论依据.

Theoretic analysis of the cat''''s eye cavity He-Ne laser

A concave mirror and a cat's eye reflector acting as a resonator mirror coustitute a cat's eye cavity. The parallelism of the incident and the reflected beams achieved by using three kinds of cat's eye reflectors (one ideal cat's eye reflector and two reflectors with errors), and the parameters of Gaussian beam in resonators which respectively use the three kinds of cat's eye reflectors are accurately calculated. We arive at the conclusion that for the Gaussian beam the cat's eye reflector is ideal and gives best parallelism of the incident and the reflected beam when the focal length of the convex lens, the radius of curvature of the concave mirror and the distance between them are equal. In this case the cat's eye cavity has the highest stability along with the largest fundamental mode volume and the least far-field divergence angle of fundamental mode. In the cavity design, one should strive to decrease the focal length of the convex lens in the cat's eye reflector and increase the radius of curvature of the output mirror. The influence on resonator performance when there are errors in the cat's eye reflector is also discussed. This paper gives a theoretical basis for the design of cat's eye cavity lasers.