Antireflection coatings on 1.55-μm LiNbO3 guided-wave devices using sputtered SiO2/Y2O3 and SiO2/TiO2 bilayers

Two anti-reflection coatings processes, based on RF magnetron sputtering, have been used to reduce the reflectance of Ti:LiNbO3 optical waveguide/fiber interface. Measurements show typical reflectance values around -25 dB and -30 dB, at 1.55 micrometers , using respectively SiO2/Y2O3 and SiO2/TiO2 bilayers.