Conditional measurements in micromasers: Role of counter-rotating processes

Abstract

We study dynamics of a micromaser field when atoms are conditionally measured at the exit from the micromaser resonator. We assume the micromaser field to be initially prepared in the vacuum state and all atoms entering the cavity are considered to be in their lower states. We consider a conditional measurement when only those realizations of the experiment are taken into account when all atoms after the interaction with the cavity field are detected in their lower states. This kind of experimental configuration allows us to study in detail the role of the counter-rotating processes in the atom field interaction. In particular, we show that as a consequence of the interplay between the rotating-wave and counter-rotating processes a quasi steady state of the micromaser field is created in the cavity. We analyse quantum-statistical properties of the micromaser field as a function of the atom-field coupling constant (given in units of the field frequency) and the interaction time.