Study On Magnetic Rotation And Scattering Characteristics Of Glass-based Two-Dimensional Photonic Crystals

With the miniaturization of photonic devices,the application of photonic crystals has become more widespread.The enhance Faraday rotation by photonic crystals is often used in designing magneto-optical modulation devices.At present,the two-dimensional magneto-photonic crystals is still hard to be manufactured by a single magneto-optical medium and short of study on detailed polarization characteristics.This paper is aimed at proposing a two-dimensional magneto-photonic crystals model that is practical and has good magneto-optical responses.In this paper,the two-dimensional photonic crystals structure consists of periodic triangular lattice air holes distributed on the Bi₂O₃-PbO-B₂O₃ glass substrate,and a point defect filled with Bi:YIG magnetic particles is set at the middle.The lattice constant and glass thickness are both 2?m.The incident light propagates along the axial direction,and the finite difference time domain method?FDTD?and the Mie scattering theory are used to calculate the polarization state and light intensity distribution of the output light.Based on the above,the effects of bubble and magnetic particle scattering on linearly polarized light and the propagation characteristics in magneto-photonic crystals are studied.In addition,the relationship between magnetic particle size,incident light wavelength and lattice filling rate and magneto-optical responses is also discussed to obtain the optimized structural parameters.Important conclusions are as follows:?1?When the diameter of the residual bubble in the glass substrate were smaller than the minimum wavelength,the negative effect of bubble scattering on the polarization state could be significantly reduced.The forward scattered light is greatly concentrated by spherical magnetic particle,while scattering has little effect on the polarization state.?2?The enhance Faraday rotation depends on the combined effect of photonic crystals structure and magnetic particles on the localization of the light field.When the wavelength matches the radius of the magnetic particles and the lattice filling ratio,magneto-photonic crystals has better magneto-optical characteristics.In addition,photonic crystals with point defects can effectively suppress linearly polarized light depolarization.?3?When the lattice filling ratio and the radius of Bi:YIG magnetic particles are 25%and 0.6?m,respectively,the Faraday rotation of the model at the wavelength of 1.2?m can reach 9.6 deg/?m.According to the simulation results,large-sized magnetic photonic crystals can be prepared to obtain large Faraday rotation.In addition,the enhance Faraday rotation by magnetic defect structure provides a new idea for designing magneto-photonic crystals.