Far-Field and Near-Field Optical Properties of Planar Plasmonic Oligomers

Abstract

Recently, a large number of experimental and theoretical works has revealed a variety of plasmonics nanostructures with the capabilities of Fano Resonance (FR) generating. FR exhibition in most nanostructures needs an excited high-order mode with a very narrow linewidth and its interference with a broad dipole mode. Newly introduced planar plasmonic oligomers, consisting of packed metallic nanoelements, tackle this challenge. Such structures can exhibit FR based on the anti-parallel dipole modes rather than an overlap between dipole and high-order modes. In this thesis a way to increase the value of ratio among anti-parallel dipole modes is investigated by reduction of the number of surrounding satellite elements to enhance the contrast of FR. Subsequently, a recipe is proposed to flexibly control the Fano profile signature. Meanwhile, the capability of oligomers to localize the near-field energy inside the arbitrary inter-particle gaps is revealed.