Abstract

We show that a coherently driven dissipative micromaser may display a new kind of bistability of the cavity field and/or the photon number. The bistability is a direct consequence of the presence of trapping states and the robustness of the related cotangent states against the perturbations caused by the cavity losses. The novel features of the bistability stem from the fact that even in the presence of cavity losses, the stationary state of the maser is close to a macroscopic superposition of number states (Schrödinger's cat) in the bistable regime. With increasing injection rate, the bistable regime of the micromaser is reached by means of a route that resembles a first-order phase transition. Hysteresis and other related irreversible effects are discussed.

© 1990 Optical Society of America