抛物反射镜对高斯束变换特性的研究

Research on the Transformation Properties of Gaussian Beam Reflected by a Parabolic Mirror

在准光技术的研究和应用中,利用解析公式设计准光系统具有方便快捷的优点。采用解析公式设计透镜和椭球反射镜组成的准光系统都得到与实际吻合的良好结果。但在使用解析公式计算抛物反射面对高斯束的变换特性时存在较大误差,不满足设计抛物面组成的准光系统的要求。为解决此问题,在Ka波段利用CST全波分析软件对高斯束经抛物面镜的变换特性进行大量仿真并进行相关的数据处理,对经典解析公式进行了校正。校正后的公式对于在Ka波段和W波段的高斯束斜入射抛物面镜问题上的计算结果与全波仿真结果有较好吻合,可以用于设计相关准光系统,同时也消除了使用全波仿真软件带来的耗时长及占用计算机空间大等问题。

In quasi-optical technique, it is convenient to use analytical formula to design the quasi-optical system. A quasi-optical system composed of lens and ellipsoidal reflectors designed by the analytical formula has good agreement with the actual results. However, there is obvious error in deducing the transformation properties of Gaussian beam reflected by a parabolic mirror with the analytical formula. That means it is not satisfied with the requirements of designing quasi-optical system composed of parabolic mirrors. Therefore, a large number of simulations about the transformation properties of Gaussian beam reflected by a parabolic mirror in the Ka-band are carried out with CST, and the analytical formula is revised with the help of the simulation results. The calculation results given by the revised formula is in good agreement with the results of the full-wave simulations about the transformation properties of Gaussian beam reflected by a parabolic mirror in the Ka-band and the W-band. As a result, this modified theoretical formula can be used not only to design the quasi optical system, but also in eliminate tbe long time-consuming computation by using full-wave simulation software.