Multimirror anastigmat design

摘要

A differential equation method has been developed for design of reflecting systems which will be completely free of astigmatism. From caustic theory and a generalization of the Coddington equations, a second order differential equation can be setup to shape a corrective mirror which eliminates all orders of astigmatism in an optical system. The constant optical path length condition is used to shape another mirror in the system to control spherical aberration. Analysis of results of application of this differential equation design approach to a two-mirror anastigmat is presented, which shows its ability to yield a two-mirror system with high performance over a large field of view.