Optically induced splitting of bright excitonic states in coupled quantum microcavities

Optically induced lifting of the degeneracy of spatially separated quantum-well excitons is reported from angular-dependent studies of coupled-quantum-microcavity structures. Interaction between the symmetric and antisymmetric photon modes of the coupled cavity and the corresponding combinations of the degenerate excitonic states gives rise to two bright excitons with a sizeable splitting of several meV, which together with the cavity modes lead to four dips in reflectivity spectra. In the near-resonance regime, evidence for motional narrowing of the polariton spectra is found.