Directional emission from WS2 monolayer coupled to plasmonic Nanowire-on-Mirror Cavity

TL;DR

This study demonstrates how coupling a WS2 monolayer to a plasmonic nanowire-on-mirror cavity enables directional control of exciton emission, with potential applications in integrated nanophotonics and quantum optics.

Contribution

It provides the first experimental analysis of directional photoluminescence from WS2 coupled to a plasmonic nanowire-on-mirror cavity, combining local field enhancement and waveguiding.

Findings

Directional emission characterized using polarization-resolved Fourier microscopy.

Enhanced local fields and waveguiding observed in the cavity structure.

Potential for on-chip nanophotonic applications demonstrated.

Abstract

Influencing spectral and directional features of exciton emission characteristics from 2D transition metal dichalcogenides by coupling it to plasmonic nano-cavities has emerged as an important prospect in nanophotonics of 2D materials. In this paper we experimentally study the directional photoluminescence emission from Tungsten disulfide (WS2) monolayer sandwiched between a single-crystalline plasmonic silver nanowire (AgNW) waveguide and a gold (Au) mirror, thus forming an AgNW-WS2-Au cavity. By employing polarization-resolved Fourier plane optical microscopy, we quantify the directional emission characteristics from the distal end of the AgNW-WS2-Au cavity. Given that our geometry simultaneously facilitates local field enhancement and waveguiding capability, we envisage its utility in 2D material-based, on-chip nanophotonic signal processing, including nonlinear and quantum optical regimes.