Coherent Polariton Modes and Lasing in ZnO Nano‐ and Microwires.

This article presents a topical literature survey on types of coherent states in bare and functionalized ZnO nano‐ and microwire microcavities, together with own new approaches of the authors. By optical excitation, coherent emission from electron–hole plasma and from exciton‐polariton Bose–Einstein condensates, both up to room temperature, have been observed by various research groups. 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 structures has been discussed. For different cavity types spectrally tunable mono‐/dual‐mode laser operation as well as propagation of coherent polariton states have been demonstrated. Further functionalization of the bare structures in hybrid systems allows optimization and engineering of the cavity as well as the polariton mode structure and the design of sophisticated light–matter states. Nano‐ and microwire microcavities and waveguides have a great potential for applications in optical data transport and manipulation for future on‐chip communication and computation. For room temperature applications, the material ZnO is auspicious. Schmidt‐Grund et al. review state‐of‐the‐art miniaturized ZnO lasers based on high‐quality self‐organized grown bare and further functionalized nano‐ and microstructures and present a novel approach for further enhancing the lasing performance. [ABSTRACT FROM AUTHOR]