两镜反射系统的初始结构求解方法

基于三级像差理论提出了一个求解两镜反射系统的初始结构的方法。在仅仅知道系统的焦距长度f，两镜之间的间隔d和后工作距离l′₂时，利用该方法能够方便而有效地计算出系统的初始结构参数。该方法的显著优点是以两镜之间的距离作为求解系统初始结构的条件，在系统的几何尺寸受到限制时，非常方便和有效。同时，由已知参数可以方便地计算主镜遮拦比和次镜放大率。最后分析了4种典型的两镜反射系统，并给出了设计实例，结果表明，此方法是相当精确的。

Method of solving the initial structure of two-mirror reflecting system

A method of solving the initial structure of two-mirror reflecting system on the basis of the tmrd order aberration theory was proposed in this paper.In With this method.the parameters of initial structure could be calculated effectively and efficiently only by knowing the system focal length f,mirror separation d and the back focal length l'2.A remarkable advantage of this method was that the directly determined separation between two milTOrs was one of the conditions of solving the initial structure,thus it wound be more convenient and efficient when the geometrical dimensions of systems were limited.At the same time,some useful formulae were derived drawn,thus the obscurafion ratio and the magnification of secondary mirror could be calculated with the given parameters.Furthermore four typical two-mirror reflecting systems were discussed and a case was designed by this method.The results show that this method is comparatively accurate.