The Resonance Properties Of SPP In Metal/Dielectric Structures Based On Grating Modulation

Surface plasmon polariton is a burgeoning field in nanophotonics, consideringlight-control properties in the microstructure of metal-dielectric with nanoscale.However, as the size of traditional optical device approach to the wavelength oflight, diffraction limit will emerge. Surface plasmon polaritons (SPPs) can breakthrough diffraction limit, thus realizing light-control in the microstructure ofmetal-dielectric with nanoscale. This thesis mainly investigates resonance,electromagnetic distribution and absorption characteristics of SPPs in themicrostructure of metal-dielectric based on grating.Firstly, the existent condition, excitation method and dispersion curve of SPPsare discussed, based on Maxwell equations. Then Rigorous Coupled-Wave Analysis(RCWA）is introduced to calculate electromagnetic wave diffraction in periodicgrating structure. The reflectivity and transmittivity of different diffraction order arecalculated in single-layer and multi-layer structure respectively. we can finally getthe dispersion curve and electromagnetic distribution of SPPs.Grating coupledmodulation is introduced to the structure of dielectric-metal-dielectric, which mainlyincludes indirect grating coupling and direct grating coupling. Influence of gratingstructure to SPP resonant character is studied by the method of RCWA.Light incident on metal grating through prim, named indirect grating coupling.Firstly, influence of grating structure to SPP resonant character is discussed. Thispaper mainly including the influence of grating period, fill factor and thickness tototal attenuated reflection curve. After that incident angle is fixed to discuss theimpact of grating period to SPP mode and electromagnetic distribution. Secondlythe reflection spectrum, dispersion curve and electromagnetic distribution ofsymmetrical structure is calculated to investigate SPP. Finally, we analyze the effectof parameters on local SPP in indirect grating coupling M/D/M structure.For direct grating coupling, light directly incident to grating and excite SPP.We firstly fix incident angle, and then investigate the influence of grating period toSPP mode in the structure of Ag grating-SiO2-Ag film. Secondly “T” shaped array isintroduced to discuss SPP resonance character and to study the impact of incidentangle, width of top grating, width of middle grating and grating period. Finally, thefield distribution of local mode and spread mode SPP is discussed with normalincidence.