Abstract

We consider a two-mode quantized field described in a coherent state interacting with a four-level atom. An effective Hamiltonian is obtained by adiabatically eliminating the intermediate two levels in a cascade process. The influence of the Stark shifts on the atomic inversion is examined, as well as on the second order auto-correlation function and on the cross-correlation between the field modes. The results of the calculations are illustrated numerically.

Key word: Adiabatic elimination, Stark-shift, second order auto-correlation function, cross-correlation between the field modes.