  We consider a cavity field state, which is created by the atom-cavity field's
interaction in the presence of a driven field. The two-level atom passes
through the cavity and is driven by a weak classical field. A photon number
dependent Stark shift is induced by the atom's dispersive interaction with the
cavity field. When the atom is in excited state $|a\rangle$, the output cavity
field thus obtained is taken into consideration. With the help of the state
evaluated, we investigate different statistical properties such as photon
number distribution, Wigner function, Mandel's $Q$ parameter and squeezing.
