Coherent Polariton States in ZnO Nano- and Microstructures

We present a survey on types of coherent states in bare and functionalized ZnO nano- and microwire microcavities. By optical excitation, we have observed coherent emission by electron-hole plasma lasing and from exciton-polariton Bose-Einstein condensates, both up to room temperature. We discuss the impact of the interplay between the excitation properties and geometry of the structures as well as of the charge carrier dynamics on the emission behavior of the structure. We demonstrate for different cavity types spectrally tunable mono-/dual-mode laser operation, propagation of coherent polariton states over at least 10 pm distance, and indication for Bogoliubov-like excitations.