Propagation Properties Of Tunable Two-dimensional Magneto-optic Photonic Crystal Waveguides

Photonic crystal is a new kind of artificial material with periodic permittivity or permeability.Because of its unique characteristics of photon band gap and photon location,it is widely used to control and manipulate the propagation of light in a certain frequency range.Especially in two-dimensional magneto-optic photonic crystals,electromagnetic waves can propagate in one direction due to the destruction of rotational magnetic effect and the time-reversal symmetry after the action of external magnetic field.Therefore,it has been attached importance to by researchers since its appearance,and has been applied in optical integrated devices.With the advent of 5G era,the performance of optical devices based on waveguides and so on must be continuously improved to meet the increasing demand of information capacity.To meet this need,researchers have been working on it.In this thesis,the propagation properties of two-dimensional magneto-optic photonic crystals(2D) composed of layered metal-spinning dielectric metamaterials are studied.On this basis,a cross waveguide which can control the transmission direction and the number of transmission ports is designed.Based on the unidirectional boundary waveguide,a new optical transmission network structure which can control the transmission path of electromagnetic wave is proposed.Finally,the transmission performance of two-dimensional magneto-optic photonic crystals made of rotating magnetic materials is studied,and a reconfigurable loop waveguide is designed by using it.In this thesis,a kind of cross waveguide is designed.A two-dimensional magneto-optical photonic crystal with triangular lattice was constructed with layered metal-spinning dielectric metamaterials as the background.Numerical simulation proved that the unidirectional boundary mode existed at the interface between air and photonic crystal.Based on the coupling effect of unidirectional boundary mode,a cross waveguide is designed.By setting the position of point source and the direction of magnetic field,the cross waveguide can not only control the direction and number of the output ports of the waveguide,but also realize the mode conversion.Then,based on the triangular lattice two-dimensional photonic crystal with layered metal-spinning dielectric metamaterials as the background,a new structure to control the propagation path and direction of electromagnetic waves is proposed.The structure is composed of a two-dimensional photonic crystal rectangular unit and an air rectangular unit."+1","-1" and "0" are taken as coding units."+1" and "-1" respectively represent the application of magnetic fields in the direction of + Z and-Z to the two-dimensional magneto-optical photonic crystal rectangular unit,and "0" represents the air unit.Three different model structures of 2×2,3×3,4×4have been constructed successively,and the transmission of electromagnetic waves in them has been simulated by software.By changing the coding sequence,the transmission path and direction of electromagnetic wave can be controlled,so as to meet the requirements of high-density optical path transmission and large-capacity information processing in the future optical integrated loop.Finally,the propagation properties of the two-dimensional magneto-optic photonic crystals constructed by yttrium iron garnet column and alumina column are studied,and a kind of loop waveguide is designed.By adjusting the frequency and position of the point source,the transmission path of the electromagnetic wave is adjusted dynamically,and the reconstruction of the loop waveguide is realized.