Thermal near-field tuning of silicon Mie nanoparticles

Artyom Assadillayev,Søren Raza,Minoru Fujii,Hiroshi Sugimoto,Tatsuki Hinamoto

doi:10.1515/nanoph-2021-0424

Artyom Assadillayev, Søren Raza + Show 3 more

Open Access

https://doi.org/10.1515/nanoph-2021-0424

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Journal: Nanophotonics	Publication Date: Oct 4, 2021
Citations: 11	License type: CC BY 4.0

Affiliation: Technical University of Denmark, Kobe University

Abstract

Abstract Tunable high-refractive-index nanostructures are highly desired for realizing photonic devices with a compact footprint. By harnessing the large thermo-optic effect in silicon, we show reversible and wide thermal tuning of both the far- and near-fields of Mie resonances in isolated silicon nanospheres in the visible range. We perform in situ heating in a transmission electron microscope and electron energy-loss spectroscopy to show that the Mie resonances exhibit large spectral shifts upon heating. We leverage the spectral shifts to demonstrate near-field tuning between different Mie resonances. By combining electron energy-loss spectroscopy with energy-dispersive X-ray analysis, we show a reversible and stable operation of single silicon nanospheres up to a temperature of 1073 K. Our results demonstrate that thermal actuation offers dynamic near-field tuning of Mie resonances, which may open up applications in tunable nonlinear optics, Raman scattering, and light emission.

Highlights

Dielectric and semiconductor nanostructures are rapidly becoming one of the main constituents in nanoscale optical devices
Using in situ energy loss spectroscopy (EELS), we show that the Mie resonances exhibit large spectral shifts upon heating and that the near-field can be dramatically altered at fixed energies
We have experimentally demonstrated that the Mie modes of silicon nanoparticles in a broad size range can be tuned using the thermo-optic effect

Summary

Introduction

Dielectric and semiconductor nanostructures are rapidly becoming one of the main constituents in nanoscale optical devices. Many applications require tunable optical elements, where the optical response can be controlled with an external stimulus [13, 14] This has prompted a strong interest in realizing dielectric optical components with a tunable far-field functionality and has led to the successful demonstrations of different tuning mechanisms, including photothermal [15, 16], electromechanical [17, 18], via photocarrier generation [19, 20], coupling to liquid crystals [21,22,23], using phase change materials [24,25,26], and through the thermo-optic effect [27, 28].

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