ABSTRACT
The last several years have witnessed an explosion of interest in understanding and exploiting the optical properties of metals and metallic nanostructures, most specifically those associated with plasmonic resonances that can give rise to pronounced optical absorption, field localization, and scattering effects. For example, surface plasmon resonances and related phenomena in metallic nanostructures are currently being exploited for a variety of applications, including molecular sensing1-3 and tagging,4,5 focusing of light,6 near-field optical microscopy,7,8 subwavelength photonics,9 and optical metamaterials.10 The appeal of plasmon excitations for such applications typically arises from the large electromagnetic field enhancement that occurs in the vicinity of the metal surface, and the dependence of the resonance wavelength on the nanoparticle’s size, shape, and local dielectric environment, or from very strong scattering effects that occur at wavelengths in the vicinity of plasmonic resonances.
