Research On Propogation Properties Of Surface Plasmon At A Metal And Nonlinear Medium Interface

Free electrons at metal surface will oscillate under the application of an external electric field to produce surface plasmon wave, and this resonance is ocalized at the metal surface and propogate along the metal surface. Surface plasma wave have a much bigger wave vector than free electromagnetic with the same frequence. This property make it widely used in scientific researches and life. The disperson relation of surface plasmom wave excitated at a metal and nonlinear medium surface can be control by changing the intensity of the electric field. In this dissertation, we study propogation properities of surface plasma at a metal and nonlinear medium interface, the research content are as follows.Deduce the dispersion relation of surface plasmon wave at a metal and nonlinear medium from the Maxwell equations under contain boundary conditions. Use the method of numerical calculation analysis the affection of dispersion relation of surface plasma wave at a metal and nonlinear medium without considering the absorption by changing the nonlinear coefficient. And further analysis the dispersion relation, the group speed and skin dept properties of surface plasma wave at nonlinear-metal-nonlinear structure. Use the method of numerical calculation analysis the affection of these parameters without considering the absorption by changing the nonlinear coefficient.Make use of absorption drude model, and according to the linear medium absorption law raised by P.Bouguer from experiment data, we research the propagation properties of surface plasma wave at a metal and absorption or gain medium. Deduce the dispersion relation of surface plasma wave at a metal and basorb or gain medium from the Maxwell equations under contain boundary conditions. And by numerical calculation, we analysis the change of dispersion properties of surface plasma wave at a metal and absorption or gain medium interface.Discuss the propagation properties of surface plasma pulse in a metal and the dielectric interface. Through the Fourier transform, we change the incident time domain pulse into the frequency domain pulse, analysis the change of surface plasma pulse after a propagation length, then conduct another Fourier transform to change the frequency domain pulse back to time domain pulse to constrast with the incident pulse. By use of numerical calculation we plot the resurt of the change of surface plasma pules afte a propagation length.