Input Impedance, Nanocircuit Loading, and Radiation Tuning of Optical Nanoantennas

TL;DR

This paper extends radio-frequency antenna concepts to optical nanoantennas, analyzing input impedance, loading, and radiation tuning to improve nanoantenna design and matching at visible frequencies.

Contribution

It introduces a framework for defining and evaluating input impedance in optical nanoantennas, enabling optimization through nanocircuit loading.

Findings

Defined optical input impedance and radiation resistance.

Demonstrated nanoantenna loading optimization using nanocircuit elements.

Extended RF antenna theory to the visible regime.

Abstract

Here we explore the radiation features of optical nanoantennas, analyzing the concepts of input impedance, optical radiation resistance, impedance matching and loading of plasmonic nanodipoles. We discuss how the concept of antenna impedance may be applied to optical frequencies, and how its quantity may be properly defined and evaluated. We exploit these concepts in optimization of nanoantenna loading by optical nanocircuit elements, extending classic concepts of radio-frequency antenna theory to the visible regime for the proper design and matching of plasmonic nanoantennas.