Compressing surface plasmons for nano-scale optical focusing.

A major challenge in optics is how to deliver and concentrate light from the micron-scale into the nano-scale. Light can not be guided, by conventional mechanisms, with optical beam sizes significantly smaller than its wavelength due to the diffraction limit. On the other hand, focusing of light into very small volumes beyond the diffraction limit can be achieved by exploiting the wavelength scalability of surface plasmon polaritons.

On long-range plasmonic modes in metallic gaps.

Satuby and Orenstein [Opt. Express 15, 4247-4252 (2007)] reported the discovery and numerical and experimental investigation of long-range surface plasmon-polariton eigenmodes guided by wide (6 to 12 mum) rectangular gaps in 400 nm thick gold films using excitation of vacuum wavelength lambda(vac) = 1.55 mum.

Nanopin plasmonic resonator array and its optical properties.

A one-step electron-beam lithography process for the fabrication of a high-aspect ratio nanopin array is presented. Each nanopin is a metal-capped dielectric pillar upon a ring-shaped metallic disc. Highly tunable optical properties and the electromagnetic interplay between the metallic components were studied by experiment and simulation.

Gap modes of one-dimensional photonic crystal surface waves.

The finite-difference time-domain method is employed for the analysis of coupling of the surface modes of two truncated one-dimensional photonic crystals separated by a gap. The wave vector, field distributions, and existence conditions of the coupled surface modes are investigated. The wave vector of symmetric gap modes increases with decreasing gap width, while that of antisymmetric modes decreases-exactly opposite of the situation for surface plasmons on metallic half-spaces separated by a dielectric gap.