Quantum-state reconstruction in the one-atom maser

We propose a reconstruction scheme for the quantum-mechanical state of a field inside a microwave cavity in the Fock representation. It will be shown that two experimental steps are required for this purpose: (i) the quantum state under consideration has to be shifted in phase space, and (ii) it has to be examined by state-selective detection of two-level atoms after a resonant interaction with the field. The method is examined in a computer simulation including measurement errors. [S1050-2947(98)04802-1].