Propagation Properties of the SPP Modes in Nanoscale Narrow Metallic Gap, Channel, and Hole Geometries

Abstract

Abstract-The propagation properties of surface plasmon polaritons (SPP) modes in nanoscale narrow metallic structures: gap, channel, and rectangular-hole waveguides, are analyzed by the complex effective dielectric constant approximation. The results show that all the SPP modes exist below the critical frequency where the real part of metal permittivity is negative unity. It is found that both cutoff frequency and cutoff height exist in channel waveguide and rectangularhole waveguide. The channel and rectangular-hole waveguides have different propagation properties at cutoffs due to their different cutoff conditions. Compared with the gap waveguide, the channel waveguide has shorter propagation length and better confinement when the operation frequency is near the critical frequency, but has longer propagation length and worse confinement when the operation frequency is far from the critical frequency. Among the three waveguides, the rectangular-hole waveguide has the best confinement factor and the shortest propagation length. The comprehensive analysis for the gap, channel, and rectangular-hole waveguides can provide some guidelines in the design of subwavelength optical devices.

Optimizing Nano-Optical Antenna for the Enhancement of Spontaneous Emission

“…Last decade has witnessed an increasing interest in electromagnetic properties of metal-dielectric structures including metallic nanoparticles [1][2][3][4][5], nano-scale narrow metallic structures [6], and nanoscale metallic waveguide [7,8]. In these previous researches, evident enhanced electromagnetic field and large density of states are obtained because SPPs excited at the surface of sharp tips can interact strongly with optical fields and confine far-field radiation into a localized, subdiffraction limited volume [9].…”

Propagation Along Single-Crystalline Silver Filaments With Pearl-Chain-Like Structures

“…Highly localized SPPs can be sustained in the terahertz region. In this case, the dispersion and mode profile of the transmitted electromagnetic waves are determined by the geometry of the corrugation on metallic structures [8][9][10]. It opens the way for important applications such as energy concentration on cylindrical wires and super-focusing using conical structures.…”

Enhanced Design of Narrowband Filters Based on the Extraordinary Transmission Through Single Fishnet Structures

“…During the next decade, a lot of noteworthy efforts have been conducted to reveal the underlying physics of this intriguing phenomenon [11,12]. The most prevalent interpretation has been derived from the generation of surface plasmons on metallic surfaces [13][14][15][16] due to the plasma-like behavior of metals at optical frequencies. Yet, experiments showed that the ET phenomenon occurs also at microwave frequencies [17], where metals act as perfect conductors and, therefore, cannot support surface plasmons.…”