Effect of Internal Atomic Relaxation on Quantum Fields

The general criteria for the quantum field features of sub-Poissonian statistics, photon anti bunching and squeezing are discussed and evaluated for the case of a two level atom driven by a near resonant monochromatic laser field and subjected to photoionization damping due to a second stronger laser. The quantum field criteria involve atomic density matrix elements satisfying optical Bloch equations. Both strong field regime analytic results and numerical calculations are given. The non classical features now only occur in the transient regime though photoionization damping often takes a long time to have an effect even when it is the dominent relaxation mechanism.