Anomalous dispersion in strongly coupled surface plasmons and single and double doped excitonic media (Invited Paper)

Controlling of light with matter is of great importance for both fundamental science and applications, including control of emission, energy transfer, chemical reactions, resistivity, surface potentials, polaritonic lasers, nanophotonics and many others. We fabricated a series of Kretschmann geometry samples and dye-doped PMMA films, with concentrations of Rhodamine dyes (Rh590 and Rh610) in the polymer (PMMA) ranging between 0 g/L and 1260 g/L and studied their absorption and reflection spectra. The angular and spectral positions of the dips in the experimental reflection spectra resulted in the dispersion curves summarized below. In brief, we have observed (i) multi-branch “staircase” dispersion curves of surface plasmon polaritons at high dye concentrations, (ii) emergence of a new “fork” branch of the dispersion curve, (iii) effect of energy transfer on strong coupling in co-doped donor-acceptor system, and (iv) effect of dye-dye interaction on spectral positions of the absorption bands, explained in terms of the second order perturbation theory.