Mirror Design For Optical Telescopes

Abstract

The reflector mirror is the most important component of an astronomical optical telescope. This chapter provides discussions on the requirements for astronom- ical optical mirrors; the ways to reduce mirror weight, mirror cost, and mirror materials; the methods of mirror figuring, polishing, and surface coating; the design of mirror support mechanism; the concept of mirror seeing; and the stray light control. Emphasis is placed on various mirror designs for modern large optical telescopes. These include the thin mirror, honeycomb mirror, segmented mirror, and multi-mirror telescope concepts. When discussing all these concepts, important formulas and their restrictions are provided for the reader’s reference so that they may use them in their mirror design practice. The discussion on the mirror support system is thorough and comprehensive, including both the positional and flotation support systems. A new mirror support system using a hexapod platform is also introduced. In the stray light control section, a new scattering theory based on the bidirectional reflectance distribution function is also introduced.