Normal incidence Raman scattering enhancement in double-cavity microresonators

We report on the observation of huge enhancements of the Raman scattering efficiency at quasi-backscattering due to double optical resonances in a microcavity. The structure, based on a double-cavity configuration separated by a central mirror, was specifically designed and grown by molecular beam epitaxy to achieve a large splitting, close to the energy of the LO phonon of GaAs, between the two confined photon modes.