The lasing operation of a ZnO planar microcavity under optical pumping is demonstrated from T=80 K to 300 K. At the laser threshold, the cavity switches from the strong coupling to the weak coupling regime. A gain-related transition, which appears while still observing polariton branches and, thus, with stable excitons, is observed below 240K. This shows that exciton scattering processes, typical of II-VI semiconductors, are involved in the gain process.
@article{arxiv.1106.0183,
title = {Laser emission with excitonic gain in a ZnO planar microcavity},
author = {Thierry Guillet and Christelle Brimont and Pierre Valvin and Bernard Gil and Thierry Bretagnon and F. Medard and Martine Mihailovic and Jesús Zúñiga-Pérez and Mathieu Leroux and F. Semond and Sophie Bouchoule},
journal= {arXiv preprint arXiv:1106.0183},
year = {2011}
}