Cavity-modified spontaneous-emission rates in liquid microdroplets

Abstract

We observe significant lifetime modification (both reduction and lengthening) of 610--620-nm light spontaneously emitted by chelated europium ions in 10-\ensuremath{\mu}m-diam dimethylformamide-alcohol solution droplets. The enhancement or inhibition of the Einstein A coefficient over the familiar free-space value is direct evidence of cavity quantum-electrodynamic effects taking place in microdroplets.