High reflectivity grating waveguide coatings for 1064 nm

Abstract

We propose thin single-layer grating waveguide structures to be used as high reflectivity, but low thermal noise, alternative to conventional coatings for gravitational wave detector test mass mirrors. Grating waveguide (GWG) coatings can show a reflectivity of up to 100% with an overall thickness of less than a wavelength. We theoretically investigate GWG coatings for 1064 nm based on tantala (Ta2O5) on a silica substrate focusing on broad spectral response and low thickness. © 2006 IOP Publishing Ltd.