REFLECTION OF THE JAYNES-CUMMINGS DYNAMICS IN THE SPECTRUM OF A REGULARLY PUMPED MICROMASER

We derive approximate analytical expressions for the spectrum of a reg ularly pumped micromaser. Our procedure is based on ensemble averaging rather than time averaging, and the results are obtained from the sol ution of a non-Markovian evolution problem. For certain values of the atom-field interaction time the spectrum is split into several equidis tant peaks. We show that this line splitting reflects the phase revers al of the entire cavity field caused by the transit of a single atom. This phenomenon is due to the occurrence of quantum Rabi oscillations and it is closely related to the Jaynes-Cummings revival.