Observation of multiple thresholds in the many-atom cavity QED microlaser

Abstract

We report the observation of multiple laser thresholds in the many-atom cavity QED microlaser. Traveling-wave coupling and a supersonic atom beam are used to create a well-defined atom-cavity interaction. Multiple thresholds are observed as jumps in photon number due to oscillatory gain. Although the number of intracavity atoms is large, up to $N\ensuremath{\sim}{10}^{3}$, the dynamics of the microlaser agree with a single-atom theory. This agreement is supported by quantum trajectory simulations of a many-atom microlaser and a semiclassical microlaser theory. We discuss the relation of the microlaser with the micromaser and conventional lasers.