High-Q microresonators unveil quantum rare events

TL;DR

This paper reveals that high-Q microresonators can detect rare quantum electrodynamical events through Raman signatures embedded in their transmission spectra, enabling new sensing and spectroscopy applications.

Contribution

It demonstrates a novel quantum cavity-QED effect where prolonged photon confinement reveals vacuum-mediated rare events in high-Q microresonators, surpassing classical linear optics limitations.

Findings

Detection of Raman signatures from quantum vacuum effects

Amplification of signals with increased analyte adsorption

Feasibility with current photonic technologies

Abstract

Classical linear optics posits that at sufficiently low intensities, light propagation in dielectric media is governed solely by their linear susceptibilities. Here, we demonstrate a departure from this paradigm in high-Q microresonators, where prolonged photon confinement enables rare quantum electrodynamical (QED) events, mediated by the quantum vacuum, to embed distinctive Raman signatures of the coupled analyte into the resonator's linear transmission spectrum despite their absence from the linear susceptibility. We further show that increasing the amount of adsorbed analyte amplifies these Raman fingerprints well above typical noise floors, rendering them experimentally accessible with state-of-the-art photonic architectures and detection schemes. This novel weak-coupling cavity-QED effect offers unique routes to harness extended photon lifetimes and constrained geometries for leveraging vacuum fluctuations in next-generation photonic technologies for chemical and biological sensing and high-precision optical spectroscopy.