Lasing from an individual ZnO hexagonal microrod on the Au surface coated by a nanometer-scaled SiO2 layer

Abstract

We demonstrate that an individual ZnO hexagonal microrod on the surface of Au substrates coated by a nanometer-scaled SiO2 layer can become a source for manufacture miniature ZnO plasmon lasers by surface plasmon polariton coupling with whispering-gallery modes (WGMs), and the SiO2 layer can tune the modes and intensity of ZnO emission. We achieve an abnormally low-threshold plasmonic WGM lasing from a ZnO hexagonal rod, and the threshold is 0.36 KW/cm2. These investigations show that this coupling mode holds a potential of ZnO hexagonal micro- and nanorods for data storage, bio-sensing, optical communications, as well as all-optic integrated circuits.