STATE EVOLUTION IN THE 2-PHOTON ATOM-FIELD INTERACTION WITH LARGE INITIAL FIELDS

The state evolution in the two-photon atom-field interaction with larg e initial fields is studied. It is shown that under certain conditions , for the initial coherent field, at one-quarter and three-quarters of the revival time the atom is converged into unique pure states, and a t the revival time both the atom and field return to their initial sta tes. The possibility for the field macroscopic superposition states to be generated is discussed. The effects of tl;e cavity damping, photon statistics, and dynamic Stark shifts are investigated. Our results gi ve some further insight into the validity of the effective two-photon Hamiltonian which neglects the Stark shifts.