title: Strong coupling of surface plasmon polaritons and ensembles of dye molecules.
abstract: We demonstrate the strong coupling of dye molecules to surface plasmon polaritons (SPPs) excited in the Kretschmann geometry and propagating at the interface of silver and dye-doped polymer. The dispersion curve of such a system, studied in the reflectometry experiments, is split into three branches and demonstrates an avoided crossing - the signature of a strong coupling. We have further studied the excitation spectra of the dye emission and found that the positions of the excitation peaks have a good match with the points in the dispersion curve determined by the reflectometry. At the same time, the analysis of the spectra of the plasmon-mediated spontaneous emission, decoupled to the prism and acquired at multiple collection angles, has resulted in a quite different dispersion curve exhibiting a non-trivial splitting into multiple branches. This suggests that the same plasmonic environment couples differently to absorbing and emitting dye molecules.
authors.forename: T U
authors.initials: TU
authors.lastname: Tumkur
authors.forename: G
authors.initials: G
authors.lastname: Zhu
authors.forename: M A
authors.initials: MA
authors.lastname: Noginov