Narrow Results

We report on the plasmonic properties of silver-coated dielectric nanocylinders arranged according to an unconventional geometrical representation called Pascal's triangle. We performed numerical simulations to calculate the extinction spectrum and identify the collective optical modes in the geometry. For resonant excitation at 410 nm, we found pronounced field localization (50 nm) at the center of the Pascal triangle. Further, we studied the near-field intensity as a function of experimentally-relevant variables such as excitation wavelength, angle of incidence and dielectric constant of the core material. Our analysis revealed pronounced difference between near-field intensities for resonant and non-resonant excitation wavelength at various angle of incident radiation; and an increment in near-field intensity at excitation wavelengths greater than 600 nm, with increase in dielectric constant of core material. Our study has relevance in development of substrates with tunable electromagnetic hot-spots for on-chip plasmonics.

In the last few years, plasmonics has attracted much attention and has been included in the principal domains of nanophotonics that can manage optical fields at the nanodimension level. Its exquisite characteristic is to increase the electromagnetic fields at the nanometer scale particularly in the solar cell. In the plasmonic discipline, noble metals used as nanoparticles in which the density of the electron gas which oscillates at surface plasmon frequency at that time also enhances absorption via scattering. So the usage of plasmonics in solar cells offers better possibility of improving the performance through absorption, because the optical spectrum loss is principal as a part of the overall loss for the solar photovoltaic cell. So we investigated the impact of the nanoparticle size for the enhancement of extinction in terms of absorption and scattering by using surface plasmon resonance, and additionally studied the finite-difference time domain (FDTD)-based proposed model and found various plasmonic fields components and characterized optical enhancement in the plasmonic thin film solar cell.

In this paper, surface plasmons polariton propagation and manipulation is reviewed in the context of experiments and modeling of optical images. We focus our attention in the interaction of surface plasmon polaritons with arrays of micro-scatereres and nanofabricated structures. Numerical simulations and experimental results of different plasmonic devices are presented. Plasmonic beam manipulation opens up numerous possibilities for application in biosensing, nanophotonics, and in general in the area of surface optics properties.

We developed a fast numerical algorithm for solving the three-dimensional vectorial Helmholtz equation that arises in electromagnetic scattering problems. The algorithm is based on electric field integral equations and is essentially a boundary element method. Nyström's quadrature rule with a triangular grid is employed to linearize the integral equations, which are then solved by using a right-preconditioned iterative method. We apply the fast multipole technique to accelerate the matrix-vector multiplications in the iterations. We demonstrate the broad applications and accuracy of this method with practical examples including dielectric, plasmonic and metallic objects. We then apply the method to investigate the plasmonic properties of a silver torus and a silver split-ring resonator under the incidence of an electromagnetic plane wave. We show the silver torus can be used as a trapping tool to bind small dielectric or metallic particles.

Two-dimensional (2D) plasmonic nanoassemblies have recently attracted growing attention due to their sophisticated structural features, multi-functional properties, and emerging applications in sensing science, anti-counterfeit solutions, nanophotonics, separation science, and catalysis. In this chapter, we cover the key methodologies developed to date with regards to precise synthesis of constituent building blocks and rational design of ordered nanoassemblies with reasonable internal and overall structural control. This is followed by the detailed discussions of the key parameters including the role of surface-capping ligands and their lattice structures. Finally, the properties and applications of 2D plasmonic nanoassemblies are described.