Surface plasmon polariton - exciton interaction in metal-semiconductor and metal-dye nanostructures

We consider the frequency- and angle-dependent reflectivity of hybrid structures containing metallic components and an optically excitable medium such as organic dyes or semiconductor quantum wells. Clear signatures of a coupling between surface plasmon polaritons and excitons in the excitable medium, in particular avoided crossings with hybridization gaps in the range ∼ 10-100 meV, are found both experimentally and theoretically.