Optical material anisotropy in high-index transition metal dichalcogenide Mie nanoresonators
Artikel i vetenskaplig tidskrift, 2020

Resonant optical antennas provide unprecedented opportunities to control light on length scales far below the diffraction limit. Recent studies have demonstrated that nanostructures made of multilayer transition metal dichalcogenides (TMDCs) can exhibit well-defined and intense Mie resonances in the visible to the near-infrared spectral range. These resonances are realizable because the TMDC materials exhibit very high in-plane refractive indices, in fact higher than what is found in typical high-index dielectric materials like Si orGaAs. However, their out-of-plane refractive indices are comparatively low. Here we experimentally and theoretically investigate how this unusually large material anisotropy influences the optical response of individual TMDC nanoresonators made of MoS2. We find that anisotropy strongly affects the far-field optical response of the resonators, as well as complex interference effects, such as anapole and resonant Kerker conditions. Moreover, we show that it is possible to utilize the material anisotropy to probe the vectorial nature of the nanoresonator internal near fields. Specifically, we show that Raman spectra originating from individual MoS2 nanoresonators exhibit mode-specific anisotropic enhancement factors that vary with the nanoresonator size and correlate with specific modes supported at resonance. Our study indicates that exploring material anisotropy in novel high-index dielectrics may lead to new nanophotonic effects and applications. (C) 2020 Optical Society of America under the terms of the OSA Open Access Publishing Agreement

Författare

Thomas D Green

Chalmers, Fysik, Bionanofotonik

Denis Baranov

Chalmers, Fysik, Nano- och biofysik

Battulga Munkhbat

Chalmers, Fysik, Bionanofotonik

Ruggero Verre

Chalmers, Mikroteknologi och nanovetenskap (MC2), Nanotekniklaboratoriet

Timur Shegai

Chalmers, Fysik, Nano- och biofysik

Mikael Käll

Chalmers, Fysik, Nano- och biofysik

Optica

2334-2536 (ISSN)

Vol. 7 6 680-686

Ämneskategorier

Atom- och molekylfysik och optik

Annan fysik

Den kondenserade materiens fysik

DOI

10.1364/OPTICA.389192

Mer information

Senast uppdaterat

2020-10-16