Exciton-polariton microphotoluminescence and lasing from ZnO whispering-gallery mode microcavities

摘要

Hexagonal ZnO microrods were employed as whispering-gallery mode (WGM) optical microcavities to investigate exciton-polariton microphotoluminescence and lasing emission. Using a confocal microphotoluminescence system, the exciton-polariton emission with a large Rabi splitting of about 90 meV was observed from a ZnO microrod with the diameter of 9.38 μm. The spatial-resolved spectra demonstrated a collective nonlinear blueshift in the WGM resonance peaks along a tapered microrod and proved the anticross dispersion property of the exciton-polariton. Furthermore, the exciton-polariton WGM lasing was stimulated and blueshifted in the strong coupling region under the excitation of a 355 nm nanosecond pulsed laser.