Emission spectra of an atom in a cavity in the presence of a squeezed vacuum

Abstract
We have investigated the interaction of a single atom with a single mode of the radiation field in an ideal cavity when the field is initially in a squeezed-vacuum state. In particular, we present results for the spectrum of the emitted light and for the time evolution of the squeezing inside the cavity. Our results contrast sharply with previous studies of single two-level atom interaction with a continuum of squeezed-vacuum modes. In particular, the results are shown to be insensitive to the initial phase of the atomic dipole relative to the squeezed field, and the squeezing is destroyed by the coherent interaction, in a time essentially independent of the initial degree of squeezing. Most features of the spectrum are very similar to those predicted for an initial thermal state, although the two-peaked structure associated with vacuum-field Rabi splitting is more apparent for a squeezed state with a small average number of photons than for a thermal state with the same number of photons.