Active control of surface plasmon resonance in MoS2-Ag hybrid nanostructures

TL;DR

This paper demonstrates active control of surface plasmon resonance in MoS2-Ag hybrid nanostructures through laser power, enabling tunable optical properties for potential nanophotonic device applications.

Contribution

It introduces an experimental method for optically tuning SPR in MoS2-Ag nanostructures and develops an analytical model explaining the underlying physics.

Findings

SPR red-shifts with increasing laser power

Spectroscopic tunability depends on near-field coupling and polarization

Potential for all-optical nanophotonic device development

Abstract

Molybdenum disulfide (MoS2) monolayers have attracted much attention for their novel optical properties and efficient light-matter interactions. When excited by incident laser, the optical response of MoS2 monolayers was effectively modified by elementary photo-excited excitons owing to their large exciton binding energy, which can be facilitated for the optical-controllable exciton-plasmon interactions. Inspired by this concept, we experimentally investigated active light control of surface plasmon resonance (SPR) in MoS2-Ag hybrid nanostructures. The white light spectra of SPR were gradually red-shifted by increasing laser power, which was distinctly different from the one of bare Ag nanostructure. This spectroscopic tunability can be further controlled by near-field coupling strength and polarization state of light, and selectively applied to the control of plasmonic dark mode. An analytical Lorentz model for photo-excited excitons induced modulation of MoS2 dielectric function was developed to explain the insight physics of this SPR tunability. Our study opens new possibilities to the development of all-optical controlled nanophotonic devices based on 2D materials.