Evolutionary optimization of optical antennas

TL;DR

This paper presents an evolutionary algorithm to optimize nano-antenna designs at optical frequencies, discovering a novel hybrid geometry that significantly improves near-field intensity enhancement over traditional designs.

Contribution

The study introduces an evolutionary optimization approach for optical nano-antennas, resulting in a new hybrid geometry outperforming conventional designs.

Findings

Optimized antenna geometry is a split-ring/two-wire hybrid.

The new design surpasses conventional gap antennas in performance.

Resonance shifted into the optical regime.

Abstract

The design of nano-antennas is so far mainly inspired by radio-frequency technology. However, material properties and experimental settings need to be reconsidered at optical frequencies, which entails the need for alternative optimal antenna designs. Here a checkerboard-type, initially random array of gold cubes is subjected to evolutionary optimization. To illustrate the power of the approach we demonstrate that by optimizing the near-field intensity enhancement the evolutionary algorithm finds a new antenna geometry, essentially a split-ring/two-wire antenna hybrid which surpasses by far the performance of a conventional gap antenna by shifting the n=1 split-ring resonance into the optical regime.