以光学系统主镜为研究对象,分析了中高频误差对散射损失比的影响。根据光学镜面面形误差近似高斯平稳随机过程特征,结合Harvey-Shack散射理论和统计光学理论,建立了光学镜面中高频误差RMS与散射损失比(RSL)之间的数学关系模型,并利用实际加工数据进行了仿真验证。研究表明,RSL随着中高频误差RMS的增加近似呈指数规律增加,同时在聚焦范围内,理论分析与仿真计算结果非常吻合。在中频误差和高频误差RMS值分别<λ/63时,对RSL的影响均<1%,结果可为中高频误差的修正提供理论支持。
In view of a primary mirror of an optical system, the influence of the mid-and-high frequen- cy errors on the Ratio of Scattering Loss (RSL) was analyzed. On the basis of the statistical optics theory and Harvey-Shack scatter theory, a mathematical model of the relationshop between the Root- mean Square (RMSs) of mid-and-high frequency errors and the RSL was established by assuming the surface errors as a stationary Gaussian random process, and the numerical computation and actual sur- face profile data of the model were validated. It is found that the RSL increases almost in exponential form with the increase of RMS and the mathematical model agrees with the simulation results very well within the focused radius. The influence of the mid-and-high frequency errors on the RSL is less than 1% when the RMSs of the mid-and-high frequency errors are less than λ63 respectively. The a- nalysis results provide the support for correction of the mid-and-high frequency errors.