Fluorescence Spectrum of an Atom Interacting with a Quantized Cavity Field with Arbitrary Nonlinearities
We present a detailed theory of a general formalism of a nonlinear JC-model. In particular we explicitly take into account forms of nonlinearities of both the field and the intensity-dependent atom-field coupling and study the properties of the fluorescence spectrum in this system. The exact solution for time-dependence of the atom-field system is obtained, by means of which we analyze the analytic form of the fluorescence spectrum produced by an atom in an ideal cavity using the transitions among the dressed states of the system. We investigate the influences of the nonlinearities on the fluorescence spectrum, for initial squeezed, thermal and coherent states. It is shown that features of the fluorescence spectrum are significantly influenced by the kinds of nonlinearities of the single-mode field.