Determination of atom-field observables via resonant interaction

We find the observables that-can be determined by two practical schemes based on atom-field resonant interaction. In the first example, the interaction is followed by photon-number and atomic-population measurements. In the second scheme the directly measured quantity is the atomic deflection. In particular, we show that they provide the measurement of the atom-field relative phase. When the initial field state is known, the atomic density matrix can be reconstructed