Probing the optical near-field interaction of Mie nanoresonators with atomically thin semiconductors

TL;DR

This paper demonstrates how dielectric Mie nanoresonators can enhance and tune the optical absorption of monolayer MoSe2 by exploiting near-field interactions, verified through experiments and simulations, offering a new way to probe near-fields without complex microscopy.

Contribution

It introduces a method to access and control the optical near-field of dielectric nanoresonators using MoSe2 monolayers as active probes, validated by experiments and simulations.

Findings

MoSe2 absorption is enhanced by nanoresonator near-field.

Spectral tuning of absorption is achieved via resonator geometry.

Spectral shifts confirm access to near-field interactions.

Abstract

Optical Mie resonators based on silicon nanostructures allow tuning of light-matter-interaction with advanced design concepts based on CMOS compatible nanofabrication. Optically active materials such as transition-metal dichalcogenide (TMD) monolayers can be placed in the near-field region of such Mie resonators. Here, we experimentally demonstrate and verify by numerical simulations coupling between a MoSe2 monolayer and the near-field of dielectric nanoresonators. Through a comparison of dark-field (DF) scattering spectroscopy and photoluminescence excitation experiments (PLE), we show that the MoSe2 absorption can be enhanced via the near-field of a nanoresonator. We demonstrate spectral tuning of the absorption via the geometry of individual Mie resonators. We show that we indeed access the optical near-field of the nanoresonators, by measuring a spectral shift between the typical near-field resonances in PLE compared to the far-field resonances in DF scattering. Our results prove that using MoSe2 as an active probe allows accessing the optical near-field above photonic nanostructures, without the requirement of highly complex near-field microscopy equipment.