Shaping the Beam of Light in Nanometer Scales: A Yagi-Uda Nanoantenna in Optical Domain

TL;DR

This paper proposes a Yagi-Uda-like optical nanoantenna using resonant core-shell particles to control light at nanometer scales, enabling tailored radiation patterns and potential applications in molecular spectroscopy.

Contribution

It introduces a novel design of optical nanoantenna with tunable radiation patterns using core-shell plasmonic particles, advancing nanoscale light control.

Findings

Nanoantenna exhibits directional radiation patterns.

Adjusting core-shell ratios tailors phase and directivity.

Potential for nanospectrum analysis in spectroscopy.

Abstract

A Yagi-Uda-like optical nanoantenna concept using resonant core-shell plasmonic particles as its "reflectors" and "directors" is studied numerically. Such particles when placed near an optical dipole source in a certain arrangement may exhibit large induced dipole moments, resulting in shaping the far-field radiation pattern, analogous to the far field of classical Yagi-Uda antennas in the microwave regime. Variation of the ratio of radii in concentric core-shell nanostructure is used to tailor the phase of the polarizabilities of the particles, and consequently the antenna's far-field pattern. The idea of a nanospectrum analyzer is also briefly proposed for molecular spectroscopy.