Laser-induced transitions between core excited states of Na

We present calculations on the dynamics of two-photon ionization of sodium involving core excited autoionizing states in the presence of two-colour radiation fields. We calculate the total ionization probability, the line shapes, and their dependence on the intensity of the laser. The atomic parameters (Rabi frequencies and ac-Stark shifts) are calculated using an MCHF method for the computation of the needed wavefunctions. The laser coupling between the core excited states of Na is shown to lead to a significant modification of the line profile which provides a measure of the dipole strength between highly correlated core excited states