Static Stark effect for alkali atoms in a strong field

Stanisław Chwirot, S. Łęgowski, Jarosław Zaremba

Petr A. Braun

Vladimir S. Smirnov, Mukhammad Bobur Sultanov, A. V. Taǐchenachev +1 more

F. O. Aleksandrov, Alexander Ya. Kazakov, P. J. Shepherd

Christophe Blondel, René-Jean Champeau, Christian Delsart

Laser investigation of the photoionization spectra in the presence of an electric field has been performed in $\ensuremath{\pi}$ and $\ensuremath{\sigma}$ polarizations on an ytterbium atomic beam from the particular level $4{f}^{14}6s7s^{1}S_{0}$ which was populated by a two-step excitation. Broad modulations (in $\ensuremath{\pi}$ polarization) and Stark resonances in the vicinity of the zero-field ionization limit are interpreted satisfactorily as in the case of alkali atoms. However, the photoionization spectra are deeply affected by the presence of two perturbing levels belonging to the configuration $4{f}^{13}5{d}^{2}6s$. This phenomenon is explained by strong interference effects between the structured Stark continuum and the field-induced autoionizing states corresponding to the doubly excited levels.

Mikhail Vladimirovich Fedorov

An analysis is made of the Stark effect in a hydrogen atom subjected to a static electric field and the field of a strong resonant electromagnetic wave. It is shown that the resonant interaction modifies the linear (with respect to the static field intensity) splitting of the atomic levels and gives rise to a quadratic shift of sublevels.