Research On Characteristics Of Metamaterial Surface Waves

Surface wave is electromagnetic wave which is confined to a very thin plane area along the direction of propagation. The amplitude will attenuate with the increased distance of deviation from the surface in the direction perpendicular to the plane. Metamaterial is an artificially structured material which has the extraordinary physical properties, and it has important applications in the field of electromagnetic invisibility cloaking, superlens and super-resolution imaging. Due to the extraordinary physical properties of metamaterial, surface waves located at the interface of metamaterial had attracted more attention. At present, metamaterial surface waves are changed by designing the structure of metamaterial. However, once the structures were designed, it could not be changed. Therefore, it has more important significance in studying the tunable characteristics. We mainly study on the tunable characteristics of metamaterial surface waves by changing the external physical field in this thesis. Specific studies and the results are as follows:1. Surface waves at the interface of superconductor media and nonlinear metamaterialThe nonlinear transverse electric surface waves which localized at the interface separating nonlinear metamaterial and superconductor media had been studied, and we obtained the dispersion relation of nonlinear surface waves based on the continuity of electric and magnetic fields at the interface. We used two-fluid model to discuss the temperature effect on the dielectric constant of high temperature superconductors, and we further discussed about the effective refractive index, energy flow distribution and the position of soliton maximum amplitude in nonlinear metamaterial by using numerical calculation. The results showed that the effective refractive index(the velocity of surface waves), the power flow distribution and the position of soliton maximum amplitude can be tuned by nonlinear terms and temperature. The position of soliton peak moves closely to the interface with the increasing of nonlinear term and goes away from the interface with the increasing temperature. The power of surface wave mainly distributed in nonlinear metamaterial in the form of soliton, and the power flow in two media can be redistributed by the temperature.2. The tuning characteristic of the external magnetic field on surface waves localized at the interface between semiconductor media and nonlinear metamaterialThe nonlinear transverse electric surface waves which localized at the interface between nonlinear metamaterial and semiconductor media had been studied, and we obtained the dispersion relation of nonlinear surface waves. We discussed about the tuning characteristics of the external magnetic field on the effective refractive index, energy flow distribution and the position of soliton maximum amplitude based on the semiconductor In Sb magneto-optic voigt effect. The results showed that the effective refractive index increases with the increase of external magnetic field when the frequency is less than the plasma frequency of semiconductor, but the effective refractive index decreases with the increase of external magnetic field when the frequency is larger than the plasma frequency of semiconductor. The effective refractive index decreases with the increasing nonlinear term. The position of soliton peak closes to the interface with the increasing of nonlinear term. The power flow distribution in two media can be tuned by the external magnetic field, and the results might be used in optical isolator.3. Surface waves at the interface of metamateria and nonlinear mediaThe nonlinear transverse magnetic surface waves which localized at the interface separating nonlinear material and linear metamaterial had been studied, and we obtained the exact dispersion relation of nonlinear surface waves at the interface. We obtained the exact dispersion relation of nonlinear surface wave by using the first integral because the transverse magnetic wave is the vector surface wave that has the two coupling electric field components. Comparing with the linear uncorrected result, we found the exact dispersion relation has an advantage in terms of accuracy and it has the deviation above 10% in the selected condition. We further discussed the characteristics of equivalent dielectric constant and the depth of penetration with the variation of electromagnetic field intensity and Kerr coefficients of nonlinear medium based on above results.