Theoretical Analysis the Optical Properties of Multi-coupled Silver Nanoshell Particles

Abstract

The surface plasmon resonances of silver nanoshell particles are studied by Green’s function. The nanoshell system of plasmon resonances results from the coupling of the inner and outer shell surface plasmon. The shift of the nanoshell plasmon resonances wavelength is plotted against with different dielectric environments, several different dielectric cores, the ratio of the inner and outer radius, and also its assemblies. The results show that a red- and blue-shifted localized surface plasmon can be tuned over an extended wavelength range by varying dielectric environments, the dielectric constants and the radius of nanoshell core respectively. In addition, the separation distances, the distribution of electrical field intensity, the incident directions and its polarizations are also investigated. The study is useful to broaden the application scopes of Raman spectroscopy and nano-optics.

Theoretical Study of the Local Surface Plasmon Resonance Properties of Silver Nanosphere Clusters

“…The data also illustrate a local minimum for the extinction efficiencies at about 320 nm, where both the real and imaginary parts of Ag dielectric parameter are expected to reach zero. Its spectral feature is inherent to the Ag materials properties, independent to the particle’s geometries, sizes, which could be seen bellow [7, 28]. In addition, the main contribution of scattering and absorption efficiencies to the extinction efficiency can be seen clearly from Fig.…”

Theoretical Analysis of Sub-Wavelength Light Propagation Through the Double-Chain Silver Nanorings

“…It is easy to image that the near field intensity is linearly decremented as ε increased due to more incident light is absorbed by higher refractive media in DHs. Their maximum SPR modes (peaks) are also toward longer wavelength as ε increased [26][27][28][29][30][31]. The apparent corresponding peak resonant wavelengths are λ = 375 nm (first peak) and 570 nm (second peak) for no DH case, λ = 380 nm (first peak) and λ = 1030-1160 nm (second peak) for DH cases as the permittivities filled inside the DHs varying from ε = 1 to ε = 5.…”

“…The dipole moments of the inner and outer surfaces of silver nanorings are arranged. A stronger coupling effect could be gotten when the thickness (v) of silver nanorings is much smaller compared with the nanoring radius (r), it will lead to a new scheme of polarization and result in a thin metallic layer, which could be described as symmetric and asymmetric modes [18,27,30]. The geometries are air/silver/air gap/silver/air for DH case with n = 1, which is very symmetric for the thin silver film, while for another six modes (n > 1), the geometry for silver film is asymmetric, i.e., air/silver/DH/silver/air, there will be two independent single-interface modes and not any mode-splitting phenomenon.…”

“…However, farfield radiation coupling between the MNPs in the array plays also an important role. From the approach used here, it is possible to estimate such a coupling [27,29]. It is well known that the localized field in the central part of a system consisting of a pair of MNPs is determined by the polarization direction of the incident light [12,30].…”

High-speed optical FSK demodulator using plasmonic nanorods

“…Depending on the position and number of the plasmonic nanorods, the absorption can be suppressed for one wavelength and maximized for the other wavelength. Moreover, according to the experimental results of [18], higher absorption coefficient can be achieved by optimum selection of separation gap of nanoparticles while in [26], the authors prove that the layout with optimum number of nanoparticles has higher absorption coefficient and has different shifted peak.…”