A new kind of spoof surface plasmon polaritons structure with periodic loading of T-shape grooves

Chongchong Chen

doi:10.1063/1.4964619

Abstract

A new kind of spoof surface plasmon polaritons (SSPPs) structure with periodic loading of T-shape grooves is introduced in this paper. Dispersion property of this proposed structure is investigated in detail, and comparisons of dispersion property of the proposed structure and that of the traditional SSPPs structures, including structure with rectangular grooves and structure with trapezoidal grooves, are also made. The SSPPs field confinement along the orthogonal directions of the proposed structure is studied. Also, some researches on the transmission loss and propagation length of the SSPPs on the proposed structure are made. All the simulation and calculations show that the proposed structure have a great improvement of SSPPs field confinement and the transmission loss is low.

Highlights

Surface plasmon polaritons (SPPs) are the surface electromagnetic (EM) waves, which is capable of guiding and localizing wave into sub-wavelength scales, propagating along the dielectric-metal interface and decaying exponentially perpendicular to the interface in the optical frequencies.[1,2] The natural surface plasmon polaritons (SPPs) exist in the visible or ultraviolet (UV) frequency band, in which metal behaves like plasma with negative permittivity below the plasma frequency, but when frequency is reduced to the far-infrared, terahertz (THz), and microwave regimes, the metals behave like a perfect electric conductor (PEC),[3] the natural SPPs cannot exist on the interface
The natural SPPs exist in the visible or ultraviolet (UV) frequency band, in which metal behaves like plasma with negative permittivity below the plasma frequency, but when frequency is reduced to the far-infrared, terahertz (THz), and microwave regimes, the metals behave like a perfect electric conductor (PEC),[3] the natural SPPs cannot exist on the interface
We have proposed a new spoof surface plasmon polaritons (SSPPs) structure with periodic loading of T-shape grooves

Summary

INTRODUCTION

Surface plasmon polaritons (SPPs) are the surface electromagnetic (EM) waves, which is capable of guiding and localizing wave into sub-wavelength scales, propagating along the dielectric-metal interface and decaying exponentially perpendicular to the interface in the optical frequencies.[1,2] The natural SPPs exist in the visible or ultraviolet (UV) frequency band, in which metal behaves like plasma with negative permittivity below the plasma frequency, but when frequency is reduced to the far-infrared, terahertz (THz), and microwave regimes, the metals behave like a perfect electric conductor (PEC),[3] the natural SPPs cannot exist on the interface. To realize the highly confined electromagnetic (EM) waves at lower frequency, called as the spoof SPPs or the designer SPPs,[4] plasmonic metamaterials have been proposed after a plenty of studies on it. The plasmonic metamaterials include the metal surfaces decorated with one-dimension arrays of subwavelength grooves,[5,6] two-dimension arrays of subwavelength holes or dimples,[7,8,9] and three-dimension metal wires with periodical array of radial grooves.[10] The properties of spoof surface plasmon polaritons (SSPPs) at terahertz or microwave frequencies are extremely similar to those of the nature surface plasmon polaritons (SPPs) at optical frequencies, though the dispersion characteristics and spatial confinement of the SSPPs are able to be controlled by changing the geometrical features of metal structure.[11] some studies indicate that when the thickness of metal structure decrease to a small limit, the corresponding dispersion relation is not almost changed.[12,13] As a result, the ultra-thin plasmonic metamaterial which can support SSPPs and was proposed.[14] As for its flexible property and use for SSPPs propagation, the ultra-thin plasmonic metamaterial has an increasing application in plasmonic function integrated circuit designing at microwave frequencies and THz frequencies. We make some comparisons between this new structure and other traditional structures, and the studies show that this proposed structure have strong localization and confinement of SPP surface-wave at a given frequency

STRUCTURE INTRODUCTION

PROPAGATION LENGTH AND LOSS

SUMMARY