Silicon Mie Resonators for Highly Directional Light Emission from monolayer MoS2

TL;DR

This paper demonstrates how silicon nanowires can be used as optical antennas to control the directionality, polarization, and spectral properties of light emitted from monolayer MoS2, enabling highly directional emission.

Contribution

It introduces a modified Mie scattering theory for dipole emission and experimentally shows enhanced directionality of MoS2 emission via coupling to silicon nanowires.

Findings

Achieved a forward-to-backward emission ratio of 20 at 680 nm.

Demonstrated control over emission directionality, polarization, and spectral properties.

Validated the theory with experimental results.

Abstract

Controlling light emission from quantum emitters has important applications ranging from solid-state lighting and displays to nanoscale single-photon sources. Optical antennas have emerged as promising tools to achieve such control right at the location of the emitter, without the need for bulky, external optics. Semiconductor nanoantennas are particularly practical for this purpose because simple geometries, such as wires and spheres, support multiple, degenerate optical resonances. Here, we start by modifying Mie scattering theory developed for plane wave illumination to describe scattering of dipole emission. We then use this theory and experiments to demonstrate several pathways to achieve control over the directionality, polarization state, and spectral emission that rely on a coherent coupling of an emitting dipole to optical resonances of a Si nanowire. A forward-to-backward ratio of 20 was demonstrated for the electric dipole emission at 680 nm from a monolayer MoS2 by optically coupling it to a Si nanowire.