Abstract by Gabriel Richardson
Javier Del Hoyo
Physics and Astronomy
ZERODUR substrates for application of high-temperature protected aluminum far-ultraviolet coatings to future NASA missions
Recent development in coating deposition processes for aluminum mirrors that are protected with a metal- fluoride overcoat have improved reflectance performance particularly in the far- ultraviolet (FUV) part of the optical spectrum. The active research in this area is motivated by the fact that these gains in reflectance are expected to significantly increase the throughput of any future FUV sensitive NASA missions into the Lyman Ultraviolet. These reflectance improvements are attributed, in part, by performing the metal-fluoride overcoat depositions with the substrates at an elevated temperature as high as 250 ◦C. ZERODUR is a widely used material as a mirror substrate because it exhibits a low coefficient of thermal expansion (CTE) over a wide range of temperatures. I will report on surface figure effects of heating ZERODUR (250 ◦C) during a simulated coating process.