Huge Enhancement of Magneto-Optical Faraday Effect in YIG Films with Disordered Multilayer Structures

Abstract

  Magneto-optical Faraday effect of bismuth-substituted yttrium iron garnet (Bi:YIG) films with disordered multilayer structures was analyzed theoretically to examine the correlation between the magneto-optical properties and the localization effect of light. The films of interest are composed of Bi:YIG layers and SiO₂ layers which are piled up in an arbitrary sequence. The results suggest that a huge enhancement of Faraday rotation angle θ_F takes place in films with appropriate layered structures for supporting the localization of light: for instance, when the film structure meets the structure of one-dimensional magneto-photonic crystal with a defect, θ_F reaches more than 160 times larger than that of a Bi:YIG single-layer film.