The Study Of SPPs Splitting In A Multilayer Metallic Films With Single Or Double Nanoslits

In recent years,surface plasmon has been widely used in many crossing field because it can break through the diffraction limit of light field and has strong local electric field enhancement effect.The excitation and propagation properties of surface plasmons are quite different from those of ordinary light fields.Traditional methods are quite limited in controlling the direction of surface plasmon propagation.In thesis paper,based on the propagation characteristics of surface plasmons in low-dimensional metallic silver struc-tures,single/double nanoslits are designed on multilayer silver films to study the splitting properties of Surface Plasmon Polariton.Firstly,based on the transmission characteristics of surface plasmons along the metal interface,a splitter with double-layer silver film is designed.In this novel,slit is placed in the upper film.By changing the position of the lower film,the plasmon is splitted towards two sides along the gap between the two films.Secondly,a cavity is designed in the lower film of the above structure.By optimizing the size of the cavity,the transmission with high SPPs splitting ratio is achieved.Finally,based on the principle of interference,a three-layer silver films structure with double slits is designed.By discussing the influence of structural parameters on the sur-face plasmons transmission performance,the beam splitting propagation of Surface Plasmon Polariton is realized.