Symmetric Surface Plasmon Polariton Mode Research Articles

Decay and propagation properties of symmetric surface plasmon polariton mode in metal–insulator–metal waveguide

Decay and propagation properties of symmetric surface plasmon polariton (SPP) mode based on metal–insulator–metal (MIM) waveguide are investigated numerically. SPP mode is excited through a dipole embedded in Al2O3 layer of Au/Al2O3/Au structure. We demonstrate that the distance between the dipole and Al2O3/Au interface is an important tunable parameter to influence the decay properties. The electric/magnetic field intensity horizontal and vertical decay lengths of symmetric SPP mode are 19nm and 24nm, respectively. Moreover, the propagation length along Al2O3/Au interface of symmetric SPP mode depends on Al2O3 layer thickness. The maximal propagation length reaches 0.608μm with Al2O3 layer thickness of 100nm. These values can provide a theoretical reference for designing a high-performance SPP source using Au/Al2O3/Au structure.

Significantly increased surface plasmon polariton mode excitation using a multilayer insulation structure in a metal-insulator-metal plasmonic waveguide.

In this paper, we propose a novel multilayer insulation structure in a metal-insulator-metal (MIM) plasmonic waveguide to explore the possibility of increasing surface plasmon polariton (SPP) mode excitation. Numerical investigations show that the effective refractive index of the multilayer insulation structure affects symmetric SPP mode excitation. The significant enhancement of electric field intensity in horizontal and vertical profiles with a dipole in SiO2 compared with in Al2O3 is observed in the proposed MIM plasmonic waveguides due to a combination of the improved optical density and dipole radiation intensities under a low refractive index. The Au/SiO2/Al2O3/SiO2/Au geometry shows the best enhancement performances, which can serve as an excellent guideline for designing and optimizing a high-performance SPP source using a multilayer insulation structure.

Extraction of optimized parameters for Si0.6Ge0.4 material and SPP mode propagation through Si0.6Ge0.4/Ag/Si0.6Ge0.4 waveguide

The Lorentz model and modified Debye model (MDM) parameters for Si0.6Ge0.4 are presented. A nonlinear optimization algorithm is developed. The obtained parameters are used to determine the complex relative permittivity of Si0.6Ge0.4, and compared with the experimental data for validation. Finally the obtained parameters are used to analyze the properties of symmetric surface plasmon polariton (SPP) mode propagation in a dielectric-metal-dielectric (DMD) material constructed with silver (Ag) and Si0.6Ge0.4 for further verifying the extracted parameters.

Erratum to: Characteristics of Symmetric Surface Plasmon Polariton Mode in Glass–Metal–Glass Waveguide

Erratum to: Characteristics of Symmetric Surface Plasmon Polariton Mode in Glass–Metal–Glass Waveguide

Characteristics of Symmetric Surface Plasmon Polariton Mode in Glass–Metal–Glass Waveguide

The propagation characteristics of symmetric surface plasmon polariton mode in a glass–metal–glass waveguide are presented. Gallium lanthanum sulfide has been taken as the glass and silver (Ag) has been used as the metal. The analysis has been done both numerically and analytically. A two-dimensional finite-difference time-domain-based simulation model has been developed in order to analyze the propagation characteristics numerically. The obtained results using numerical and analytical methods have been compared and a very good agreement has been found.

Influence of Insulator Layer Width on Propagation Properties of Symmetric Surface Plasmon Polariton Mode in Metal-Insulator-Metal Waveguide

Influence of insulator layer width on propagation properties of symmetric surface plasmon polariton (SPP) mode, which is excited through a dipole embedded in SiO2 layer of Au/SiO2/Au structure in metal-insulator-metal (MIM) waveguide, has been investigated. The symmetric SPP mode has a propagation length along SiO2/Au interface that depends on SiO2 layer width. Its maximal value is 0.61 μm with SiO2 layer width of 100 nm. These values provide a theoretical reference for designing a high-performance SPP source using Au/SiO2/Au structure.

Propagation Properties of Symmetric Surface Plasmon Polaritons Mode in ${\rm Au}/{\rm Al}_{2}{\rm O}_{3}/{\rm Au}$ Waveguide

Propagation properties of symmetric surface plasmon polariton (SPP) mode excited through a dipole embedded in Al <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> O <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sub> layer in Au/Al <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> O <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sub> /Au waveguide have been investigated. The skin effect of symmetric SPP mode vertical to Al <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> O <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sub> /Au interface is presented. The skin depths in the Au layer and in the intermediate Al <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> O <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sub> layer are 12 and 24 nm, respectively. Moreover, the propagation properties of symmetric SPP mode along Al <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> O <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sub> /Au interface are also analyzed. The propagation lengths of electric and magnetic field component are 0.4 and 0.8 μm, respectively. It is expected that this study will provide additional understanding to the coupling between SPP sources and plasmonic waveguides.

Effect of dipole location on profile properties of symmetric surface plasmon polariton mode in Au/Al2O3/Au waveguide

This study uses a dipole embedded in Al2O3 layer to excite a symmetric surface plasmon polariton (SPP) mode in Au/Al2O3/Au waveguide to investigate its profile properties by using finite-difference time-domain (FDTD) method. The excited dipole decay radiatively direct near-field coupling to SPP mode owing to thin Al2O3 layer of 100 nm. The effects of electric and magnetic field intensity profiles and decay length have been considered and characterized. It is found that dipole location is an important factor to influence the horizontal and vertical profile properties of symmetric SPP mode in Au/Al2O3/Au waveguide. The amplitudes of electric and magnetic field intensity and the wavelengths of metal-insulatormetal (MIM) SPP resonance mode can be tuned by varying dipole location. The horizontal and vertical decay lengths are 19 and 24 nm, respectively. It is expected that the Au/Al2O3/Au waveguide structure is very useful for the practical applications of designing a SPP source.

Characterization of the terahertz near-field output of parallel-plate waveguides

We experimentally characterize the field confinement properties of various parallel-plate waveguide (PPWG) geometries in the terahertz spectral range. In contrast to infinite-width PPWGs with free-space diffraction along the unshielded direction, finite-width (and also tapered) PPWGs show well-confined THz fields at the output facet. Both the transverse field component, perpendicular to the inside surfaces, and the longitudinal component, parallel to the propagation direction, exhibit strong lateral confinement. We also observe an antisymmetric longitudinal field distribution across the air gap, analogous to the symmetric surface plasmon polariton mode observed in optical slot waveguides.

Enhanced photoluminescence from dye layers embedded in metal–insulator–metal structures

Photoluminescence spectra of a dye layer embedded in a metal–insulator–metal structure are investigated. Peculiar behaviors of the emission peaks observed can be well explained by a photoluminescence mechanism mediated by a symmetric surface plasmon polariton mode supported by the metal–insulator–metal structure. The enhancement in the photoluminescence intensities relative to those of a reference sample is clearly demonstrated. Theoretical analyses suggest that the enhancement in emission process is dominant.

Modification of dispersion, localization, and attenuation of thin metal stripe symmetric surface plasmon-polariton modes by thin dielectric layers

We systematically investigated the properties of the fundamental symmetric surface plasmon-polariton mode supported by a finite width gold microstripe with thin dielectric layers placed above and below it. This paper describes the dispersive behavior of the fundamental symmetric mode and the dependence of its attenuation and confinement on the thin dielectric layers’ thickness and refractive index. When the dielectric layers have a refractive index less than that of the cladding, the dispersion curve shifts toward the cladding light line and the mode attenuation is reduced with the tradeoff of reduced confinement. For dielectric layers with an index of refraction higher than that of the cladding, the dispersion curve shifts away from the cladding light line and the mode confinement is enhanced at the cost of increased attenuation. When designed properly, the higher refractive index dielectric layers in combination with the low index cladding can achieve tight mode confinement which cannot be obtained by using either a high or low index homogeneous dielectric cladding. The dependence of the mode’s properties on the thickness and width of the metal stripe and dielectric layers is also investigated.