title: Characterization of one-dimensional lasing in semiconductor disordered nanopowders.
abstract: In this paper, we present characteristics of one-dimensional ZnO-based random lasers by using a time-domain traveling-wave model. The results reveal that by increasing pump intensity, at first the number of laser modes is increased, and then it gets saturated. Also, output intensity shows that by increasing pump pulse width at a fixed pump intensity, laser modes are made to appear; at first, by raising pump pulse width, more laser modes appear, and then the intensity of the output spectrum is increased. Additionally, we show that by nonuniform pumping, a single-mode laser can be achieved. Through investigation of the nanopowder's average size, we show that the output spectrum has its highest intensity and the sharpest laser modes for average nanopowder sizes less than 100 nm. Moreover, the results show that by decreasing pump area, lasing threshold is inclined.
authors: Department of Nanotechnology, Tarbiat Modares University, Tehran, Iran.
authors: Peyman
authors: P
authors: Rafiee
authors: Gholamhossein
authors: G
authors: Haghighat
authors: Vahid
authors: V
authors: Ahmadi