Four families of flat-field three-mirror anastigmatic telescopes with only one mirror aspherised

摘要

In a recent paper the author described a method of acquiring the complete solution set of three-mirror anastigmatic telescopes with concave primary mirrors in which only one mirror is allowed to depart from being strictly spherical. There the solution sets were defined over a plane in constructional parameter space and four loci of points were identified representing solutions in which the Petzval curvature for the system was also zero. In the work presented below curves are fitted to these points. These curves represent the fall range of possible flat-field three-mirror anastigmats with two spherical mirrors. Examples are given from each of the four families and algorithms are given in spreadsheet format which, for each of the four curves, will deliver a complete set of constructional parameters for a flat-field three-mirror anastigmat with two spherical mirrors for a given single input parameter.