Laser probe of the atomic ionization continuum: Stimulated recombination into an excited state

A two-laser theory is formulated for the photoionization of Li atoms. The first laser is tuned above the ionization threshold of $\mathrm{Li}\mathrm{}\left(2s\right)\mathrm{}$. The second laser probes the ionized target. Stimulated recombination into $\mathrm{Li}\mathrm{}\left(\mathrm{ns}\right)\mathrm{}$ occurs near the Raman-type resonance point ${\epsilon }_{\mathrm{ns}}-{\epsilon }_{2s}-{\epsilon }_1+{\epsilon }_2=0\mathrm{}$ (where $n>\mathrm{}2\mathrm{}$ and ${\epsilon }_q$ is a photon energy). Near the resonance point the ionization probability is characterized by a line profile which resembles that for an autoionizing resonance.