Whispering Gallery Modes in ZnO Polyhedral Microcrystals

The development of effective UV microlasers, as well as the study of the nature of stimulated emission in such microcavities, is an important task of modern laser physics and optoelectronics. This work investigates lasing in ZnO polyhedral microcrystals, which are a useful structure for studying room temperature lasing and stimulated emission in ZnO. It is shown that whispering gallery modes (WGMs) are excited in the crystals 10-15 µm in size in the near UV region. Low thresholds of WGM lasing allow using excitonic recombination mechanisms for the formation of the optical gain.