Chiroptical response of a single plasmonic nanohelix

TL;DR

This paper experimentally and theoretically investigates the chiroptical response of a single plasmonic nanohelix, analyzing its scattering, emission, and resonance behavior to understand its chiral optical properties.

Contribution

It provides a detailed experimental and theoretical analysis of the chiroptical response of a single plasmonic nanohelix, including multipole analysis and higher-order resonance behavior.

Findings

Experimental characterization of scattering at fundamental resonance.

Verification of angular emission patterns experimentally.

Explanation of chiral dipole formation at higher-order resonance.

Abstract

We investigate the chiroptical response of a single plasmonic nanohelix interacting with a weakly-focused circularly-polarized Gaussian beam. The optical scattering at the fundamental resonance is characterized experimentally, and the chiral behavior of the nanohelix is explained based on a multipole analysis. The angularly resolved emission of the excited nanohelix is verified experimentally and it validates the theoretical results. Further, we study the first higher-order resonance and explain the formation of chiral dipoles in both cases.