Plasmon-exciton strong coupling in a hybrid system of gold nanostars and J-aggregates

Hybrid materials formed by plasmonic nanostructures and J-aggregates provide a unique combination of localized and enhanced electro-magnetic field in metal constituent with large oscillator strength and extremely narrow exciton band of the organic component. The coherent coupling of the plasmons of the multi-spiked gold nanostars and the excitons of JC1 dye J-aggregates results in a Rabi splitting reaching 260 meV. Importantly, broad absorption features of nanostars extending over a visible and near-infrared spectral range allowed us to demonstrate double Rabi splitting resulting from the simultaneous coherent coupling between plasmons of the nanostars and excitons of J-aggregates of two different dyes.