Thermo-optical reshaping of SHG emission from dimerall-dielectric nanoresonators

TL;DR

This paper theoretically investigates how thermally-induced changes in resonant all-dielectric nanostructures can reshape second-harmonic generation emission patterns, enabling potential subwavelength thermally switchable nonlinear optical devices.

Contribution

It introduces a novel concept of thermo-optical reshaping of SHG emission in dielectric nanoresonators, demonstrating control over emission patterns without reducing SHG efficiency.

Findings

Thermal tuning can reconfigure SHG emission patterns.

Resonant states enable efficient light-to-heat conversion.

Potential for subwavelength thermally switchable nonlinear devices.

Abstract

In recent years resonant semiconductor and all-dielectric nanophotonics offered a lot of possibilities for thermally-induced light manipulation at the nanoscale. Owing to high-quality resonant states, such nanostructures allow for efficient light-to-heat conversion supported by various temperature detection approaches based on thermally sensitive intrinsic optical responses (photoluminescence, Raman scattering, thermorefraction etc.). In this work, we study theoretically a phenomenon of the photothermal reshaping of the radiation pattern of second-harmonic generation (SHG) that occurs in resonant all-dielectric systems. In the suggested geometry near-IR pulsed laser is utilized for excitation of SHG while simultaneous continuous wave visible laser heats the structure. The thermooptical switching of the resonant optical states in the nanostructures governs the reconfiguration of the emission pattern, without significant loss in the magnitude of the SHG. We believe, that our findings will pave the way for subwavelength-size near-IR thermally switchable nonlinear optical devices.