Identifying Plasmon-Exciton Coupling in Au Nanoislands Coated with Thin Films of J-Aggregates

Abstract

The coupling between plasmons and excitons gives rise to a hybrid quasiparticle known as a plexciton. Plexcitons have vast sensing applications in photodetection, refractive index sensing, gas sensing, probing hot carriers, creation and detection of entangled states, etc. Plexcitonic coupling can exist in the weak coupling, intermediate coupling and strong coupling regimes. Of these regimes, strongly coupled plexcitonic states are the hardest to create and observe, and yet are the most desirable for high fidelity sensing applications. Herein, we report the observation of Rabi splitting in cyanine dye J-aggregates on gold nanoislands, which indicates strong plasmon-exciton coupling.