24 July 2014 Enhanced far-ultraviolet reflectance of MgF2 and LiF over-coated Al mirrors
Author Affiliations +
This paper presents and discuss data obtained on a distribution of Al+MgF2 and Al+LiF witness coupons that show substantial gains in reflectance in the far-ultraviolet (FUV) part of the optical spectrum (90−180 nm). These samples, which have dimensions of 2×2 inches, were coated at various locations inside a 2−me diameter coating chamber at the Goddard Space Flight Center in Greenbelt, MD (USA). These experiments were done to demonstrate a scale−up process for coating up to a 1−m diameter optic, and hence realize the gain in throughput that could be obtained for a telescope system that would employ such mirror coatings. These coatings have been optimized for Lyman-alpha (121.6 nm) or lower wavelengths and they are prepared with the deposition of the MgF2 or LiF layers done at elevated (∼ 250 °C) temperature. These results will be compared to ambient or “cold” depositions. We will also present optical characterization of little-studied rare-earth fluorides, such as GdF3 and LuF3, that exhibit low absorption over a broad wavelength range and could therefore be used as high-index materials to produce dielectric coatings at FUV wavelengths.
© (2014) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
Manuel A. Quijada, Manuel A. Quijada, Javier Del Hoyo, Javier Del Hoyo, Stephen Rice, Stephen Rice, "Enhanced far-ultraviolet reflectance of MgF2 and LiF over-coated Al mirrors", Proc. SPIE 9144, Space Telescopes and Instrumentation 2014: Ultraviolet to Gamma Ray, 91444G (24 July 2014); doi: 10.1117/12.2057438; https://doi.org/10.1117/12.2057438


Coatings for UVOIR telescope mirrors
Proceedings of SPIE (September 21 2015)
Enhanced MgF2 and LiF over coated Al mirrors for FUV...
Proceedings of SPIE (September 12 2012)
Progress in new ultraviolet reflective coating techniques
Proceedings of SPIE (September 15 2011)
Mirror coatings with atomic layer deposition: initial results
Proceedings of SPIE (September 20 2012)

Back to Top