Silicon offers significant advantages over other optical substrate materials such as beryllium, silicon carbide and glass for both cryogenic and high-energy laser applications. Silicon is quickly and inexpensively super-polishable (surface figure < (lambda) 10 p-v at (lambda) equals 632.8 nm; surface roughness < 5 angstroms rms), has superior thermal properties at cryogenic temperatures, and can be lightweighted. This paper updates our progress towards producing dimensionally stable ultra-lightweight silicon optics for both cryogenic instruments and high-energy infrared laser systems. We review cryogenic figure test results for three-inch diameter coupons, present analysis results for a half-meter diameter silicon foam-core mirror and tell how these results apply to a Silicon Lightweight Demonstration Mirror, and describe optics being designed for an Offner Relay System.

Date Published: 6 March 2001
PDF: 11 pages
Proc. SPIE 4198, Optomechanical Engineering 2000, (6 March 2001); doi: 10.1117/12.417349

Published in SPIE Proceedings Vol. 4198:
Optomechanical Engineering 2000
Mark A. Kahan, Editor(s)