High Reflectivity of Silver Extended Down to 200 NM
Silver has the highest reflectance of all of the metals, but it tarnishes in the presence of sulfides, chlorides, and oxides in the atmosphere. Also, the silver reflectance is very low at wavelengths below 400 nm making aluminum more desirable mirror coating for the W region. We have found a way to prevent silver tarnishing by sandwiching the silver layer between two thin layers of NiCrN{sub x}, and to extend the metal's high reflectance down to 200 nm by depositing the (thin) Ag layer on top of Al. Thus, the uv is transmitted through the thin Ag layer below 400 nm wavelength, and is reflected from the A1 layer underneath. This W-shifted durable coating provides a valuable alternative to the aluminum coating for telescope mirror coatings where collection efficiency is an important consideration.
- Research Organization:
- Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)
- Sponsoring Organization:
- US Department of Energy (US)
- DOE Contract Number:
- W-7405-ENG-48
- OSTI ID:
- 15005391
- Report Number(s):
- UCRL-JC-144144; TRN: US200322%%411
- Resource Relation:
- Conference: Optical Society of America's Eighth Topical Meeting on Optical Interference Coatings, Banff, Alberta (CA), 07/15/2001--07/20/2001; Other Information: PBD: 4 Jun 2001
- Country of Publication:
- United States
- Language:
- English
Similar Records
Durable silver mirror with ultra-violet thru far infra-red reflection
Prevention of corrosion of silver reflectors for the National Ignition Facility