The technology of diamond turning of germanium, and the computational power of computer-aided mechanical design have now reached the point at which complex optomechanical layouts can now be considered for thermal imaging telescopes, with high confidence that the finished assembly will perform as predicted. This paper describes the specification, the optical design, and the mechanical design of a three-field telescope, designed to suit the tasks of parent vehicle guidance, target acquisition, and target identification.
D R Barron, D R Barron,
"A Three-Field IR Telescope", Proc. SPIE 0655, Optical System Design, Analysis, Production for Advanced Technology Systems, (31 October 1986); doi: 10.1117/12.938425; https://doi.org/10.1117/12.938425