Dresden 2009 – wissenschaftliches Programm
HL 17.3: Vortrag
Dienstag, 24. März 2009, 10:30–10:45, BEY 154
Laser oscillation thresholds for ZnO nanowires — Mariano A. Zimmler1, Jiming Bao1, Kristen A. Sunter1, Federico Capasso1, Sven Müller2, and •Carsten Ronning3 — 1School of Engineering and Applied Science, Harvard University — 2II. Institute of Physics, University of Göttingen — 3Institute of Solid State Physics, University of Jena
In our work, we will present direct evidence of the transition from ASE to laser action in optically pumped ZnO nanowires at room temperature. The optical power evolves from a superlinear to a linear regime as the pump power exceeds threshold, concomitant with a transition to directional emission along the nanowire and the emergence of well defined cavity Fabry-Perot modes around a wavelength of 385 nm. The laser oscillation threshold is found to be strongly dependent on the nanowire diameter, with no laser oscillation observed for diameters and lengths smaller than ~150 nm and ~3 microns, respectively. Furthermore, we will present an alternative *head on* detection geometry for measuring the output power of a single nanowire laser, which provides a useful benchmark for the future development of these nanoscale devices.