Research On Goos Hanchen Shift Based On Hyperbolic Dispersion Characteristics

The hyperbolic dispersion characteristic usually refers to the dielectric constant or permeability tensor of a material,where the sign of one principal component is opposite to the sign of the other two principal components,making the isofrequency curve of the material present a hyperbolic shape,showing extremely strong anisotropy.Materials based on hyperbolic dispersion characteristics have electromagnetic characteristics that are unmatched by general materials.In the past decades,hyperbolic dispersion characteristics have attracted widespread attention and have potential applications in many fields,including optical waveguides,super lens imaging,broadband absorption,etc.Goos-H(?)nchen(GH)shift refers to the distance between the actual reflection point and the incident point(that is,the geometric optical reflection point)when light is totally reflected.In recent years,with the continuous development of GH shift related research,GH shift has been widely used in optoelectronic fields such as optical switches,optical biosensors,and integrated optics.In this paper,we have studied the hyperbolic dispersion characteristics in the infrared band based on the periodic structure of graphene/medium and the asymmetric structure of graphene,and analyzed the enhancement and regulation of GH shift.The main research contents are as follows:1.Based on the equivalent medium theory,a mathematical model for calculating hyperbolic dispersion parameters in different graphene/medium structures is established,and the numerical calculation of the GH shift is realized by combining the transfer matrix method and the steady-state phase theory.2.We theoretically studied the enhancement and regulation of the GH displacement on the surface of the graphene/dielectric periodic structure when TM polarized light in the infrared band is incident.The simulation results show that when the appropriate incident wavelength is selected,the graphene/dielectric periodic structure exhibits hyperbolic dispersion characteristics and the maximum GH shift of about 400 times the wavelength can be obtained,when the incident angle changes between 56.3° and 56.4°When the GH shift is positive and the GH shift will decrease with the increase of the Fermi energy level,when the incident angle is between 29.9° and 30.0°,the GH shift will be negative and the GH shift will increase with the Fermi energy The increase of the level increases,and the GH shift will also be affected by the number of graphene layers and the thickness of the medium.3.We theoretically studied the hyperbolic dispersion characteristics of a graphene-based asymmetric structure in the infrared band and the enhancement and regulation of the GH shift of the structure surface.The relative permittivity components parallel to and perpendicular to the surface of the structure are affected by the Fermi level and can achieve different signs in the infrared band.Therefore,we predict that by changing the Fermi level,the GH shift can be enhanced and adjusted.The simulation results show that when the wavelength is around 2.6?m,the relative permittivity component perpendicular to the surface of the structure undergoes positive and negative jumps.When this wavelength is selected for GH shift calculation,the GH shift of about 800 times the wavelength can be obtained.And we found that the GH shift can be adjusted by changing the Fermi level,the inclination angle of the graphene layer,the spacing of the graphene layers and other parameters.