Extraordinary magneto-optical effect of transmitted wave phase change in periodic diffraction structures

Based on the results of electromagnetic simulations for a dielectric structure comprising a grating over a homogeneous layer, a new magnetooptical effect is predicted according to which the phase of the transmitted zeroth order of diffraction must exhibit resonant variation during a change in the magnetization of the material. The structure is magnetized in the plane of the grating, in a direction perpendicular to its grooves. Since the magnitude of this effect is greater by several orders than that of the analogous effect for a homogeneous magnetized layer, the new effect is called extraordinary. The phenomenon is given a theoretical explanation based on a resonance excitation of an eigenmodes in the structure and the dependence of the mode frequency on the magnetization. It is shown that a large change in the phase of the transmitted order of diffraction is achieved at a certain ratio of the resonant and nonresonant diffraction processes.