Mode conversion characteristics of multimode magneto-optical Bragg diffraction cells

Abstract

We study the dependence of magneto-optical (MO) coupling coefficients on the modal fields for the design of multi-mode MO Bragg cells. The mode conversion and diffraction efficiencies between the same order TM and TE modes can theoretically be up to about 98% by adjusting the excitation frequency of the fundamental-mode magneto-static forward volume wave (MSFVW) in the bismuth-substituted yttrium iron garnet film at the optimized thickness and length. The different order mode conversion is also available by means of the higher-mode MSFVWs. The resulting mode conversion-based switch function is discussed.