Research On Spoof Surface Plasmon Polaritons And Confined Waveguides

Surface plasmon polaritons (SPPs) are electromagnetic excitations which propagate like waves along the planar interface between a metal and a dielectric, and spoof surface plasmon polaritons are ones propagating along periodically textured metal surfaces. As the effective plasma frequency of textured metal surfaces was controlled by geometric parameters, engineering surface plasmon on subwavelength scale becomes available at low frequencies, and this approach has already been validated in the microwave and terahertz regimes. These years, the concept of spoof SPPs is extended to the optical and telecom ranges. In this paper, we study a V-shaped dielectric groove and a periodically corrugated metallic groove for guiding electromagnetic waves at telecom wavelengths. We find that SPPs sustained by V-shaped grooves drilled in fully filled rectangular-shaped metallic grooves can exhibit simultaneously subwavelength field confinement and relatively long propagation length at telecom wavelengths. Another structure, which consists of alternating triangular (V-shaped) and rapezoidal metallic grooves, can also fulfill this target. For the second guiding scheme, it is found that the confinement of SPPs is very sensitive to the lower width of the trapezoidal groove, so we can achieve energy concentration through gradually increasing the lower width of the waveguide structure. We also propose a plasmon waveguide with above mentioned merits for microwave and terahertz regimes, and our numerical simulations validate it.