Efficient excitation and tuning of toroidal dipoles within individual homogenous nanoparticles

TL;DR

This paper demonstrates that toroidal dipoles can be efficiently excited and spectrally tuned within homogeneous metallic nanoparticles by adjusting radial anisotropy, advancing control over light scattering phenomena.

Contribution

It reveals the excitation and spectral tuning of toroidal dipoles in homogeneous metallic nanoparticles, a novel insight in light scattering research.

Findings

Toroidal dipoles can be excited in metallic nanoparticles.

Spectral tuning achieved via radial anisotropy adjustments.

Enhances understanding of light scattering mechanisms.

Abstract

We revisit the fundamental topic of light scattering by single homogenous nanoparticles from the new perspective of excitation and manipulation of toroidal dipoles. It is revealed that besides within all-dielectric particles, toroidal dipoles can also be efficiently excited within homogenous metallic nanoparticles. Moreover, we show that those toroidal dipoles excited can be spectrally tuned through adjusting the radial anisotropy parameters of the materials, which paves the way for further more flexible manipulations of the toroidal responses within photonic systems. The study into toroidal multipole excitation and tuning within nanoparticles deepens our understanding of the seminal problem of light scattering, and may incubate many scattering related fundamental researches and applications.