High reflectivity grating waveguide coatings for 1064nm

摘要

We propose thin single-layer grating waveguide structures to be used ashigh-reflectivity, but low thermal noise, alternative to conventional coatingsfor gravitational wave detector test mass mirrors. Grating waveguide (GWG)coatings can show a reflectivity of up to 100% with an overall thickness ofless than a wavelength. We theoretically investigate GWG coatings for 1064nmbased on tantala (Ta2O5) on a Silica substrate focussing on broad spectralresponse and low thickness.