Extraordinary Optical Transmission And Optical Waveguide Filter Based On Suface Plasmon Polaritons

There are surface plasmon polaritons(SPPs)on the interface between the metal and the medium.When the interface between the metal and the medium is applied with a high frequency electromagnetic field,the electrons on the interface generate a collective oscillation and are transmitted in the form of sparse waves along the interface.When the collective oscillation frequency of the electron coincides with the frequency of the incident light wave,the energy of the incident light wave is effectively converted into the collective vibration of the free electrons on the metal surface,thereby forming a special electromagnetic mode,and the electromagnetic field is confined to the interface between the metal and the medium.And the energy is exponentially attenuated on both sides of the metal and the medium.SPPs bound to the metal surface can break through the diffraction limit of light,which is beneficial to complete the control of nanoscale size and provide the possibility of integration of micronano photonic devices.In this paper,the finite element method(FEM)is used to study the transmission characteristics of surface plasmon waveguide and the anomalous transmission of single-slit and grooved nanostructures.The main research work of this paper is as follows:1.The Single nano-metal stitch structure has simple structures and is easy to integrate,so it usually used in the nanostructures of the sourcesurface plasmon polarizers(surface plasmon polaritons,SPPs)to construct a light souce.However,there is a problem says that the single nanometer seam has a low transmittance,So how to improve its transmittance is what we should to focus on.In order to further improve the transmittance of the single nano-slit,this paper has advanced the structure of the distributed bragg reflector(DBR)and the metal-silver thin film nanostructures,and designed grooves on both sides of metal silver film.When the TM polarized light is incident from the side of the DBR to the DBR-silver nano-seam structure,the Tamm plasmon polaritons(TPPs)and the SPPs which are excited by the left side of the silver film on the DBR-silver film interface,and the SPPs on the right side of the silver film are excited simultaneously.Finally,the local field effect of the tam element and the coupling effect between the groove and the single nanotube increase the excitation efficiency of the surface plasmon,furthermore the quasi Fabry-Perot resonance effect in the nanoslit is taken into consideration,In this paper,the finite element method(FEM)is used to study the effect of nano-seam on the nano-seam Of the transmission characteristics.After a series of parameter optimization,the maximum transmittance of the DBR-silver nano-seam groove structure is increased to 0.22,this transmittance is increased by22 times compared with the transmittance(0.01)of silver silt structure.Slight higher than the16 times gives by previous literatures.The results of the study have some certain application value in the fields of nano optical,optical signal transmission and so on.2.Based on the propagation characteristics of surface plasmon subwavelength structure,a novel optical filter composed of circular and rectangular resonators is proposed,and its characteristics are studied by finite element method.The micro-cavity resonance mode is used to realize the transmission control of the surface plasmon in the waveguide.The selective filtering of the 450nm~750nm band can be achieved by changing the microcavity size parameter,and it exhibits a linear change.When the radius of the circular cavity increases by10 nm,the selective notch filter is forbidden under other conditions.Band wavelength increases by almost 30 nm at the same interval.The results of this paper can be used in the design of multi-channel band-stop filters.