Radiation Hard Multi-Layer Optical Coatings

Next-generation space telescopes require advanced optical coatings to provide low-loss polarization-preserving transmission/reflection of light in a variety of spectral ranges. These coatings also need to protect optical components as well as the coatings themselves, from damage in a space environment. For example, one of the critical technologies identified in the NASA capabilities roadmap for advanced telescopes and observatories is advanced optical coating technology for cryogenic mirrors that is uniform and polarization preserving in the visible through far IR regions as well as improved dichroic, spectral and combiner coatings . To address this need Nanohmics is investigating us of sputter deposited amorphous nitrides and oxides as high quality, long lived radiation resistant coatings for production of anti-reflection and bandpass coatings on optical substrates including metals, PMMA, beryllium and other materials. Discussions with the contracting officer's technical representative indicated that the main Fresnel lens in the EUSO (Extreme Universe Space Observatory) may be a good candidate for amorphous nitride anti-reflective coatings. The Phase II effort will focus on coatings for PMMA based optics; however, this coating technology can be applied to many other optical systems.