Atomic interferences are observed in the micromaser when the inversion of the atoms leaving the cavity is measured while the cavity frequency is scanned across the atomic resonance. The interferences are due to the nonadiabatic mixing of dressed states at the entrance and exit holes of the maser cavity. The interference structures are triangular shaped and approximately equidistant. They are associated with the dynamics of the atom-field interaction, show quantum jumps, and demonstrate bistability of the micromaser field.

• Received 3 August 1995

DOI:https://doi.org/10.1103/PhysRevLett.75.3446