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. The two metallic pieces play asymmetrical roles in their coupling to each other due to their drastic size difference. The structure can lead to ultrasensitive surface-enhanced Raman scattering chemical sensor arrays, etc. Resonant excitation of localized surface plasmons in metallic nanostructures is one of the major approaches for concentrat-ing and enhancing electromagnetic energy on the nanoscale.1-4 It offers unique opportunities for the development of near-field optical microscopy with subwavelength resolution,5-9 high-resolution lithography,10 coupling of light into and out of photonic nanocircuits,1-3,11-14 etc. One of the most important applications of localized surface plasmons is new sensors based on surface-enhanced Raman scatterin