title: Lasing characteristics of an optically pumped single ZnO nanosheet.
abstract: We report the lasing characteristics of a single ZnO nanosheet optically pumped by ultraviolet laser beam. The ZnO nanosheets were synthesized by a carbothermal chemical vapor deposition method. The ZnO nanosheets dispersed on a silica glass substrate were excited by the third-harmonic of a Q-switched Nd:YAG laser (λ = 355 nm, τ = 5 ns) and photoluminescence from a single ZnO nanosheet was observed. The observed emission spectra showed the obvious lasing characteristics having modal structure and threshold characteristics. The threshold power for lasing was measured to be 50 kW/cm2, which was much lower than 150 kW/cm2, the threshold power of the reference ZnO nanowire. It indicates that the ZnO nanosheet is a superior gain medium for an ultraviolet laser. The oscillation mechanism inside a ZnO nanosheet is attributed to the micro-cavity effect, based on the three-dimensional laser-field simulation.
authors: Department of Electrical Engineering, Kyushu University, 744, Motooka, Nishi-ku, Fukuoka 819-0395, Japan. okazaki@laserlab.ees.kyushu-u.ac.jp
authors: Kota
authors: K
authors: Okazaki
authors: Daisuke
authors: D
authors: Nakamura
authors: Mitsuhiro
authors: M
authors: Higashihata
authors: Palani
authors: P
authors: Iyamperumal
authors: Tatsuo
authors: T
authors: Okada