Polarization research of YIG based two-dimensional Magneto Photonic Crystals

In this paper, the axial propagation of light in two-dimensional YIG based MPCs (Magnetic Photonic Crystals) was simulated by three dimensional FDTD (Finite Difference Time Domain) algorithm with Matlab and Rsoft tools. The effects of structure, filling rate of lattice, wavelength of incident light and the external magnetic field on polarization of the output light were discussed. According to the simulation, a specific structure with 25% filling rate, 1.2 μm wavelength and 2um lattice constant in the absence of defects in MPCs was validated as an ideal model to obtain a good magneto-optical response. When a central defect existed, the Faraday rotation angle increased and the ellipticity of polarization was suppressed to a certain extent for the broken periodicity of the original structure. The defect model can reach a rotation angle of 9.4 degrees, which is larger than the angle of 8.3 degrees of non-defect model when transmitting a distance of 0.5 μm under the condition of the same incident light wavelength of 1.2 μm and filling rate of 25%. A large Faraday rotation in short propagating distance was obtained when a certain polarization degree was maintained, which can be used in magneto-optical modulation devices.