Magneto-optical resonances in periodic dielectric structures magnetized in plane

We studied the magneto-optical properties of a magnetized diffractive structure composed of a binary diffraction grating and a homogeneous layer. The structure is magnetized in-plane and the magnetization vector is perpendicular to the grating slits. By the electromagnetic modeling, the structure is shown to produce magneto-optical effects in the form of the resonant change of transmittance and reflectance in response to changing magnetization. The said resonant effects are found to occur both for TE- and TM-polarization of the incident wave. The dispersion curves for the structure eigenmodes have been derived by calculating the complex poles of the scattering matrix. Analysis of the dispersion curves shows that frequencies of the magneto-optical resonances coincide with those of the structure eigenmodes. We studied in which way the dispersion curves vary when the structure material is being magnetized. We propose a classification of magneto-optical resonances based on their relation with the symmetry of eigenmodes excited in the structure.