Theoretical aspects of three-photon two-color ionization of xenon through ac-stark-shifted resonant rydberg states

Summary, in English

We present a theoretical analysis of a recent experiment [J. Opt. Soc. Am. B 6, 1513 (1989)] on two-color threephotonionization of Xe through resonant even-parity Rydberg states. We calculate second-order ac-Stark shifts, two-photon Rabi frequencies, and ionization widths by using wave functions obtained from a multichannel quantum-defect-theory analysis of the Rydberg series in Xe. We perform a detailed description of the experiment, usingthe density-matrix formalism, accounting for the temporal and spatial distributions of the laser fields. Theagreement with the experiment is good except for the ac-Stark shift of the Rydberg states, which, in our calculationis close to the ponderomotive energy, whereas in the experiment it is measured to be half of this value.