Mechanisms for Lasing with Cold Atoms as the Gain Medium

Abstract

We realize a laser with a cloud of cold rubidium atoms as gain medium, placed in a low-finesse cavity. Three different regimes of laser emission are observed corresponding, respectively, to Mollow, Raman, and four-wave mixing mechanisms. We measure an output power of up to $300\mu \mathrm{W}$ and present the main properties of these different lasers in each regime.