Strong coupling between surface plasmons and excitons in an organic semiconductor

Phys Rev Lett. 2004 Jul 16;93(3):036404. doi: 10.1103/PhysRevLett.93.036404. Epub 2004 Jul 15.


We report on the observation of a strong coupling between a surface plasmon and an exciton. Reflectometry experiments are performed on an organic semiconductor, namely, cyanide dye J aggregates, deposited on a silver film. The dispersion lines present an anticrossing that is the signature of a strong plasmon-exciton coupling. Mixed states are formed in a similar way as microcavities polaritons. The Rabi splitting characteristic of this coupling reaches 180 meV at room temperature. The emission of the low energy plasmon-exciton mixed state has been observed and is largely shifted from the uncoupled emission.