Research Of The Optical Properties On The Surface Of Topological Insulators,Chern Insulators And Chiral Metamaterials

In recent years,through artificial materials,people have acquired many unique optical properties that natural materials do not have.Advances in the field of nanofabrication offer the possibility of precise microstructural control,making the structure of special material easier to implement,which greatly promotes the research of special materials.The Faraday effect and the Kerr effect are the most important magneto-optical effects in the field of optical communication and optical recording.The properties of chiral metamaterials,Chern insulators and topological insulators are studied in this paper and the influence of various parameters on their properties is discussed.The specific work is as follows:(1)Firstly,in this thesis,the popular special materials in recent years and their characteristics are briefly introduced.Then,the research history and research status of optical properties are introduced.In section 2,the characteristics and the previous studies of chiral metamaterials,Chern insulators and topological insulators are reviewed.In this paper,the rotation angle and polarization conversion rate of special materials are calculated by the Jones vector method and transfer matrix method.(2)The Fresnel coefficients for the reflected and refracted light across the interface between two dimensional Chern insulators and chiral metamaterials are investigated.According to the calculation results,we focus on the optical properties of reflected light-Kerr effect at the interface between two materials.We show that,when the linearly polarized light is obliquely incident on the interface,the TE?TM or TM?TE can be realized by satisfying the complete polarization conversion condition.Furthermore,when the incident is larger than the critical angle,the total internal reflection occurs and only partial polarization conversion can be realized.When incident angle is smaller than the critical angle,the cross-coupling effect of chiral metamaterials will rotate the reflected plane of polarization and change the polarization state to elliptically polarized;while the topological effect of Chern insulators can only rotate the reflected plane of polarization.Adding Chern insulators to chiral metamaterials increases the polarization conversion,and can achieve complete polarization conversion under certain conditions.The properties of the Chern insulators are affected by the frequency,so that the desired Kerr effect can be easily obtained.(3)Due to small refracted polarization of the single-layer topological insulator,the Faraday effect of refracted light through a multilayer structure are enhanced.The refracted coefficients matrix of the multilayer topological insulator structure is calculated by the transfer matrix method,and the Faraday angle under different conditions is simulated.The time-reversal symmetry is destroyed by covering the surfaces of the topological insulator with the magnetic layer.Under certain conditions,the Faraday effect of the parallel magnetization is stronger than the anti-parallel magnetization.The TM mode polarized light has a larger maximum value of the polarization plane deflection angle when the polarized light of the TE mode is incident.Therefore,this paper focuses on the parallel magnetization multilayer topological structures,and studies the effect of layer number,topological magnetoelectric effect and the influence of material parameters on the Faraday effect.The results show that when linearly polarized light is incident,the transmitted light can achieve a large deflection angle of nearly 90° by selecting the appropriate number of layers and topological magnetoelectric values.