Transmission Characteristics Of Dielectric-loaded And Hybrid Plasmonic Waveguides

Surface plasmon polaritons (SPPs) are electromagnetic waves propagating at themetal-dielectric interface. It can break the diffraction limit of light due to their tight fieldconfinement to the metal surface. Plasmonic waveguides have the promise to be an idealcandidate for the highly-integrated photonic circuitry. In general, plasmonic waveguideshave a trade-off between their mode confinement and propagation length. Among them,the dielectric-loaded surface plasmon waveguide(DLSPW) and hybrid plasmonic waveg-uide (HPW)are found to be relatively superior: they all have a relatively large propagationlength with a subwavelength mode confinement. In this paper, we systematically investi-gate a novel DLSPW and HPW's transmission characteristics depended on the geometryand then proceed to achieve the structure optimization.The paper firstly start from Maxwell equations' derivation to briefly analyze theplasmonic basic theory and introduced plasmonics' concept and characteristics. Based onthis, finite element method(FEM) is utilized to investigate the transmission characteristicsof MIM and IMI symmetric structure.Based on the studying of traditional rectangle DLSPW, we propose novel ellipticalwedge DLSPW and hybrid DLSPW. FEM is applied to study the transmission characteris-tics, including mode field distribution, effective index, propagation length, mode size andfigure of merit. We conclude that the transmission characteristics of elliptical wedge DL-SPWisobviouslybetterthantraditionalrectangleDLSPW.ThehybridDLSPWmaintainsa volume3times smaller than traditional DLSPW and have favorable mode confinement.In addition, novel hybrid wedge plasmonics waveguide is proposed, whose transmissioncharacteristic is obviously better than metal wedge waveguide.Hybrid plasmonics waveguides exhibit the best prospect of achieving improved op-tical performance in practical implementations. We briefly describe the waveguide cou-pling process by physical meanings rather than formula derivation and present an detailedperformance analysis of hybrid DLSPW and hybrid wedge waveguide based plasmonicdirectional coupler. The coupler shows pretty coupling performance.