  The transient evolution of nonclassical radiation fields interacting with an
atom in a cavity is correlated to the atomic dynamics. Connection between the
atomic phases of collapse and revival, and the Wigner function pattern is
explored. Initial classical coherent field can evolve into nonclassical field.
Schrodinger cat state field is generate during the atomic collapse phase. For
initial Schrodinger cat field state, the state dissolves with time but revives
during the atomic phase that corresponds with the initial phase. More intricate
but orderly characteristics are found between the collapse-revival dynamics and
the patterns of the Wigner function for initial thermal field.
