The Protection of Front Surfaced Aluminium Mirrors with Diamond-Like Carbon Coatings for Use in the Infrared,
ROYAL SIGNALS AND RADAR ESTABLISHMENT MALVERN (ENGLAND)
Pagination or Media Count:
It has recently been shown that aluminium mirrors protected with a variety of thin passivation layers have severe reflectivity losses in the 8-12 micrometer spectral region when used at oblique incidence. This memorandum presents measurements and calculations illustrating this effect and derives the condition that the loss will occur if cos phi n sub 1 sq k sub 1 sq to the minus 12 power where phi is the angle of incidence. Its main purpose is to propose the use of an infrared transmitting diamond-like carbon coating for metallic reflectors in this 8-12 micrometer band. These coatings, in addition to being abrasion resistant and chemically durable, do not exhibit a reflectivity loss at angles of incidence of practical importance.
- Coatings, Colorants and Finishes