Interference effects in laser-induced continuum structures and autoionizing atomic states

We study, in the adiabatic regime, the interference effects-induced by strong laser fields in the continuum of an atom. A parametrized formula for the differential photoionization cross section in the vicinity of overlapping resonances was derived. Calculations were performed for the 3p(2) S-1 and 3p3d P-1 pair of autoionizing states in Mg coupled directly by a laser field, and for the overlapping laser-induced continuum structures in the H atom created by two strong laser fields that induce coupling between the 2s, 5s, 5d and 5g states via the continuum. The results for Mg agree with the experimental data for ion yield measured in the two-photon ionization of the Mg. atom via the 3p(2) S-1 AIS coupled with the 3p3d P-1 state. The interference effects induced by laser fields in the photoabsorption spectra are very similar to those appearing due to configuration interaction in overlapping autoionizing states.