Plasmonic Cavity Coupling

The large losses of plasmonic nanocavities, orders of magnitude beyond those of photonic dielectric cavities, places them, perhaps surprisingly, as exceptional enhancers of single emitter light–matter interactions. The ultraconfined, sub-diffraction-limited mode volumes of plasmonic systems offer huge coupling strengths (in the 1–100 meV range) to single quantum emitters. Such strengths far outshine the coupling strengths of dielectric microcavities, which nonetheless easily achieve single emitter “strong coupling” due to the low loss rates of dielectric cavities. In fact, it is the much higher loss rate of plasmonic cavities that make them desirable for applications requiring bright, fast-emitting photon sources. Here we provide a simple method to reformulate lifetime measurements of single emitters in terms of coupling strengths to allow a useful comparison of the literature of plasmonic cavities with that of cavity-QED, typically more closely associated with dielectric cavities. Using this approach, we...