Photoluminescence at low temperature is studied for a CdTe-based microcavity tuned to resonance with a quantum well exciton. Two distinct stimulation effects are observed with increasing excitation. The first one is associated with the lower polariton state in the strong exciton-photon coupling regime. This effect, whose physical origin has not yet been identified, could be favored by the higher stability of exciton in CdTe. The second stimulation, obtained for much higher excitation, can be assigned to the electron-hole plasma in the weak coupling regime.

• Received 27 April 1998

DOI:https://doi.org/10.1103/PhysRevLett.81.3920