Integrating yttrium iron garnet onto nongarnet substrates with faster deposition rates and high reliability

Magneto-optical garnets (Y3Fe5O12 or YIG) were grown monolithically by a novel reactive radio-frequency sputtering method that used a partial pressure differential to increase sputtering rates. MgO and quartz substrates were used as they are good buffer layers and optical claddings for integration. A wide single-phase field for annealed YIG was found (26.9–43.2at% Y), and the magnetic properties were measured. The films had refractive indices of 2.1 and out-of-plane Faraday rotations up to 0.2°∕μm at 633nm. The dielectric matrix was used to calculate the difference in the propagation constants of forward and backward traveling light (Δβ=1.999×10−5).