Neodymium random lasers operating in different pumping regimes

Abstract

In this paper we review the basic properties of neodymium random lasers, the simplest sources of simulated emission where the feedback is provided by scatters. We show that in spite of the fact that the behaviours of random laser emission are strongly different in different pumping regimes, the stimulated emission threshold energy E th remains invariant, equal to the product of the threshold pumping power P cw th in the continuous-wave regime and the spontaneous emission lifetime τ, if the duration pulse is shorter than τ.