Acceleration and adiabatic expansion of multi-state fluorescence from a nanofocus

TL;DR

This paper demonstrates a broadband, non-resonant plasmonic waveguide that significantly enhances multi-state fluorescence from Erbium ions, enabling room-temperature resolution of Stark-split transitions and potential applications in quantum networks.

Contribution

It introduces a novel reverse nanofocusing plasmonic waveguide that achieves broadband emission enhancement and resolves multiple quantum states at room temperature.

Findings

Over 590-fold emission enhancement across the telecom band.

Resolution of Stark-split electric dipole transitions at room temperature.

Brighter emission than non-plasmonic controls.

Abstract

Since Purcell's seminal report 75 years ago, electromagnetic resonators have been used to control light-matter interactions to make brighter radiation sources and unleash unprecedented control over quantum states of light and matter. Indeed, optical resonators such as microcavities and plasmonic nanostructures offer excellent control but only over a limited spectral range. Strategies to tune both emission and the resonator are often required, which preclude the possibility of enhancing multiple transitions simultaneously. In this letter, we report a more than 590-fold radiative emission enhancement across the telecommunications emission band of Erbium-ions in silica using a single non-resonant plasmonic waveguide. Our plasmonic waveguide uses a novel reverse nanofocusing approach to efficiently collect emission, making these devices brighter than all non-plasmonic control samples considered. Remarkably, the high broadband Purcell factor allows us to resolve the Stark-split electric dipole transitions, which are typically only observed under cryogenic conditions. Simultaneous Purcell enhancement of multiple quantum states is of interest for photonic quantum networks as well as on-chip data communications.