High Reflectivity of Silver Extended Down to 200 NM

Conference · Mon Jun 04 04:00:00 EDT 2001

DOI:https://doi.org/10.1364/OIC.2001.TuF2· OSTI ID:15005391

Thomas, N L; Wolfe, J D

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., CA (US)
• Sponsoring Organization: US Department of Energy (US)
• DOE Contract Number: W-7405-ENG-48
• OSTI ID: 15005391
• Report Number(s): UCRL-JC-144144
• Country of Publication: United States
• Language: English

Related Subjects

32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATION
ALUMINIUM
CHLORIDES
COATINGS
EFFICIENCY
MIRRORS
OXIDES
REFLECTIVITY
SILVER
SULFIDES
TELESCOPES
WAVELENGTHS