Thermal near‐field tuning of silicon Mie nanoparticles
Artyom Assadillayev, Tatsuki Hinamoto, Minoru Fujii, Hiroshi Sugimoto, Søren Raza
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.