Photoemission and photoelectron spectra from autoionizing atoms in strong laser field.

Joseph W. Haus, Maciej Lewenstein, Kazimierz Rza̧żewski

Alexander B Voitkiv, V. A. Pazdzerskii

Alexandr I. Magunov, Markus Müller, I. Rotter +1 more

G. S. Agarwal, Stanley L. Haan, Keith R. Burnett +1 more

Photoemission spectra from autoionizing states in the presence of a strong laser field are calculated. Such spectra have very sharp features near "confluence" (at the Fano minimum) and are very similar, in structure, to photoelectron spectra. The total intensity, as a function of laser intensity or detuning, has a peak near confluence, which can be used, among other things, for the accurate determination of Fano asymmetry parameter $q$.

Guanhua Yao, Zhizhan Xu

Strong laser-field-induced autoionisation in the presence of both photoionising and radiative decay of the autoionising state (AS) is investigated, focusing on the laser intensity dependence of the photoemission and photoelectron spectra. In contrast to previous predictions, power broadening and increasing reduction of the doublet peak heights with field strength are found in the photoemission spectrum. Similar effects leading to considerable suppression and even complete disappearance of the lowest-order peaks in the photoelectron spectrum, together with peak switching, are also demonstrated, which are closely related to above-threshold ionisation. In addition, it is suggested that the total number of energetic photoelectrons may serve as an alternative to measuring the atomic parameters of the AS. All these effects are attributed to the presence of the strong 'probe': laser-induced decay of the AS.

G. S. Agarwal, Stanley L. Haan, J. Cooper

Spectral features of the radiation emitted by autoionizing states in the presence of a strong laser field are calculated under the condition of multiple photon absorption and emissions. The method is based on the exact solution of the master equation for the recycled system. The decay spectra are found to exhibit sharp maxima at the laser frequency and, for large values of the Fano $q$ value, sidebands which are reminiscent of the triplet which one finds in the context of a two-level atom.