Electric-field-induced random lasing from ZnO and Mgo0.1Zno 0.9O films optically pumped with an extremely low intensity

Ultraviolet random lasing from ZnO and Mg0.1Zn0.9O films have been achieved under optical pump of a continuous wave He-Cd laser as the films are simultaneously exerted by an electric-field with appropriate polarity and amplitude. With the aid of electric-field, the optical pump intensity for generating random lasing can be reduced at least five orders of magnitude in comparison with conventional pulse-laser pumped ones. It is believed that the role of electric-field exerted on the films is similar to that of increasing optical pump intensity, in terms of increasing the amount of non-equilibrium electrons in the near-surface regions of films. (c) 2009 Optical Society of America