Guiding properties of a planar waveguide based on a three-periodic magnetophotonic crystal

Subject of the study. This study investigates an optical waveguide based on a one-dimensional three-periodic magnetophotonic crystal composed of dielectric and ferrite garnet layers magnetized to saturation. Aim of the study. The study aims to determine the frequency regions in which hybrid modes exist and to establish the polarization structure of guided modes in a magnetophotonic waveguide. It also examines the influence of 180° magnetization reversal and the demagnetization of magneto-optical layers on the shape of the dispersion spectra. Method. The study employs the 4×4 transfer-matrix method. Main results. The influence of the parameters of magnetic and nonmagnetic layers (including the number of subcell periods and bigyrotropy) on the dispersion spectra of the eigenwaves of a photonic-crystal waveguide is analyzed. The results show that the magnetization of the layers leads to the formation of hybrid modes from the TE- and TM-polarized modes of the unperturbed structure. This magnetization also produces convergence regions between neighboring dispersion curves and causes a noticeable frequency shift (approximately 9×10 ⁹ rad/s) in the propagation constant of the waveguide modes relative to the corresponding values in the demagnetized state of the system. Practical significance. The findings can be applied to the design of new magneto-optical devices based on three-periodic photonic crystals operating in the infrared range, such as narrowband tunable filters and beam formers for laser diodes used in optical communication systems.