Conference paper
Directional Secondary Emission of a Semiconductor Microcavity
We investigate the time-resolved secondary emission of a homogeneously broadened microcavity after resonant excitation. The sample consists of a 25nm GaAs single quantum well (QW) in the center of a wedged ¥ë cavity with AlAs/AlGaAs Bragg reflectors, grown by molecular beam epitaxy. At zero detuning equal linewidths of 180 ¥ìeV are observed for the three polariton modes.
When resonantly exciting the lower polariton mode, the seconfary emission shows a strong directional dependence due to its large in-plane dispersion. Four different components of the emission can be distinguished. (i) strong coherent emission scattered in the directions [110], [110] by nonresonant scattering of the Bragg-mirrors. (ii) coherent emission scattered on a ring with nearly constant in-plane momentum ©¤|k| by random disorder of the QW or the mirrors. (iii) an incoherent emission on a similar ring, possibly by photoluminescence of impurities. (iv) an incoherent emission over a wide emission angle range, by photoluminescence of QW excitons.
The dynamics and the dependence on the excitation condidtions and lattice temperature are presented and used to identify the origin of the different components.
Language: | English |
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Year: | 2000 |
Proceedings: | Spring Meeting of the Condensed Matter Division of the Deutsche Physikalische Gesellschaft |
Types: | Conference paper |
ORCIDs: | Hvam, Jørn Märcher |