NONGUIDING SEMICONDUCTOR MICROCAVITY - EXCITON-PHOTON MODE SPLITTING AND PHOTOLUMINESCENCE DYNAMICS

We report on the fabrication of a nonguiding half-wave semiconductor m icrocavity containing two quantum wells, and present time resolved pho toluminescence measurements under resonant and non-resonant excitation with a variable detuning between the cavity and the quantum well exci ton. When tuning the cavity length, the emission spectra present the c haracteristic polariton-like dispersion branches with a 4.6 meV splitt ing at the anti-crossing. On the exciton-like part of each branch, the emission dynamics is similar to the emission of a bare quantum well. However on the photon-like part, the radiative lifetime is considerabl y shortened. We describe these features by a polariton type model: mix ed exciton-photon states arise from the strong radiative coupling betw een the two oscillators and present a radiative decay time which refle cts the respective proportion of exciton and photon in their wavefunct ion.