Abstract
We consider the problem of a two-level atom with degenerate two-photon transitions interacting with a single-mode radiation field in the presence of a parametric frequency-converter term. A Hamiltonian representing such a system contains three time-dependent coupling parameters. We obtain an exact solution of the wave function in the Schrodinger picture, using the canonical transform and under a certain choice of the coupling parameters. We use the results obtained to discuss the atomic inversion as well as the linear entropy in addition to both the variance and entropy squeezing. We show that the system at a certain time is sensitive to variations in both the detuning parameter Delta and the ratio of the coupling parameter g.