Enhanced thermo-optical response by means of anapole excitation

TL;DR

This paper introduces a spectrally tunable anapole nanoheater that significantly enhances thermal response using dielectric resonators, enabling efficient heating at lower light intensities and spectral shifting from SWIR to NIR.

Contribution

It presents the first demonstration of a dielectric anapole resonator used to amplify thermo-plasmonic heating and achieve spectral tunability in nanoheaters.

Findings

Ten-fold amplification of thermal response with anapole modes

Ability to shift thermal response from SWIR to NIR

Enhanced heating efficiency at lower light intensities

Abstract

High refractive index dielectric nanostructures offer a versatile platform to control light-matter interaction at the nanoscale as they can easily support electric and magnetic modes with low losses. An additional property that makes them extraordinary is that they can support low radiative modes, so-called anapole modes. In this work, we propose a spectrally tunable anapole nanoheater based on the use of a dielectric anapole resonator able to amplify ten-fold the thermal response of a plasmonic nanoheater. This would allow the use of lower light intensities to achieve striking heating effects. As proof of concept, we perform a detailed study of the thermo-plasmonic response of a gold nanoring used as heating source and a silicon disk, designed to support anapole modes, located in its center acting as anapolar resonator. Furthermore, we utilize the anapole excitation to easily shift the thermal response of these structures from SWIR to the NIR range.