Electrical Control of Optical Emitter Relaxation Pathways enabled by Graphene

TL;DR

This paper demonstrates electrical control over the relaxation pathways of erbium ions near graphene, enabling dynamic tuning of emission processes at telecom wavelengths for advanced photonic applications.

Contribution

It introduces in-situ electrical modulation of emitter relaxation pathways via graphene, a novel approach for active control in quantum photonics.

Findings

Relaxation rate modified by over three times

Controlled decay into electron-hole pairs, photons, or plasmons

Achieved dynamic, electrical tuning of optical energy transfer

Abstract

Controlling the energy flow processes and the associated energy relaxation rates of a light emitter is of high fundamental interest, and has many applications in the fields of quantum optics, photovoltaics, photodetection, biosensing and light emission. While advanced dielectric and metallic systems have been developed to tailor the interaction between an emitter and its environment, active control of the energy flow has remained challenging. Here, we demonstrate in-situ electrical control of the relaxation pathways of excited erbium ions, which emit light at the technologically relevant telecommunication wavelength of 1.5 $\mu$m. By placing the erbium at a few nanometres distance from graphene, we modify the relaxation rate by more than a factor of three, and control whether the emitter decays into either electron-hole pairs, emitted photons or graphene near-infrared plasmons, confined to $<$15 nm to the sheet. These capabilities to dictate optical energy transfer processes through electrical control of the local density of optical states constitute a new paradigm for active (quantum) photonics.