| 摘要 |
A Cassegrain optical system has a concave primary mirror deployed for receiving incident electromagnetic radiation and generating once-reflected rays, a convex secondary mirror deployed for receiving the once-reflected rays and generating twice-reflected rays, a tertiary reflector deployed for receiving the twice-reflected rays and generating thrice-reflected rays, and a beam-folding optical element deployed between the primary mirror and the secondary mirror for deflecting the thrice-reflected rays laterally so as to exit a volume between the primary and secondary mirrors. |
