Effect of radial anisotropy on plasmonic optical properties of coated nanorods

Abstract

Plasmonic optical properties in pairs of coated nanorods in near-field are investigated by finite element method. The coated nanorod is composed of a radically anisotropic dielectric core and a metallic shell. Numerical simulations show that for a finite radial permittivity εr, with the increase of the tangential permittivity εt, the position of the near-field intensity peak shifts to long wavelength along with the decrease in the magnitude. On the other hand, with increasing εr, the position of the intensity peak exhibits long-wavelength shift significantly, while keeping the maximal magnitude for isotropic case. Furthermore, a compensating effect for the decay of the intensity with the incearse of the gap width can be achieved by manipulate the anisotropy of the dielectric core. ©2009 IEEE.