Ultraviolet microphotoluminescence resonance and lasing action in a single ZnO micro-tetrapod

ZnO micro-tetrapod microstructures were fabricated by a vapor phase transport method. Under the excitation of 325 nm continuous wave He–Cd laser, the microphotoluminescence spectrum from a single ZnO micro-tetrapod presented a two-band structure with a series of optical resonance modes; a possible optical resonance loop formed in two adjacent legs of the tetrapod was suggested, and the two-band spectrum structure was attributed to the exciton–exciton scattering process. The lasing emission was obtained from single ZnO micro-tetrapod under intense excitation of 355 nm nanosecond pulsed laser. The lasing spectrum shows clear mode structure with the lasing quality factor of 1300 and the lasing threshold of 150 kW/cm2. The microphotoluminescence resonance and lasing results indicate that ZnO tetrapod can serve as a high-Q ultraviolet microcavity laser.