Abstract
We report the observation of resonant Raman scattering in the strong coupling regime for a planar microcavity containing cyanine dye J aggregates. The giant Rabi splitting between the polariton branches, resulting from the very large exciton oscillator strengths, allows the observation of doubly resonant Raman scattering where both incident and scattered photons are in resonance with the mixed exciton-cavity-mode states. Under double resonance conditions the Raman signals are found to be very significantly enhanced, by factors up to 300, relative to noncavity organic films.