AbstractWe present the polarization behavior of the exciton-polariton luminescence of a ZnO-based all-oxide resonator. A splitting in the emission energy between the s- and p-polarized pho-toluminescence of the lower polariton branch was observed which increases with increasing emission angle. It is caused by the polarization behavior of the uncoupled cavity-photon mode, and reaches a maximum of about 5 meV at an emission angle near the bottleneck region. For lar-ger angles the energy splitting decreases. Additionally to the energy splitting, we observed dif-ferences in the photoluminescence intensity which we trace back to different occupation of the lower polariton branch for the two polarizations. Whereas for p-polarization a bottleneck effect is clearly observable, this effect is much weaker for s-polarization. These findings indicate that the relaxation of hot carriers into the bottleneck region is enhanced for the p-polarized photolumi-nescence compared to the s-polarized one. The differences between these two polarizations are most pronounced for a very large negative detuning and vanish with increasing detuning.
Broadening of upper polariton branch in GaAs, GaN, and ZnO semiconductor microcavities
