Résumé
Exciton and polariton spin beats are observed in a CdMnTe quantum well embedded in a microcavity using time-resolved Kerr rotation experiments under magnetic field. Photoinduced linear birefiringence phenomenon allows to comprehend the polariton spin beats using linear polarized pumping in Faraday geometry. Exciton spin beats can be detected in the standard configuration with circularly polarized pump pulse and under in-plane magnetic field.