Random lasing with red-shift discrete modes in ZnO particles

Abstract

This study reported nonlinear combination of multi-photon absorption and exciton–exciton collision induced random lasing (RL) emission from zinc oxide (ZnO) excited by femtosecond laser excitation. Strong RL with signal peaks centered at 407, 412 and 417[Formula: see text]nm while excited at 800[Formula: see text]nm wavelength pulses was observed. The threshold of the RL peak is about 0.9[Formula: see text][Formula: see text]. Unlike the conventional three-photon excited RL phenomena centered at 390[Formula: see text]nm, the violet discrete lasing modes ranging from 407[Formula: see text]nm to 417[Formula: see text]nm may occur because of the excitonic stimulation. The red-shift of lasing mode signals may be attributed to exciton–exciton interaction enhanced electron–hole plasma emission.