Two-color ionization of hydrogen for frequencies in the 2:3 ratio

Abstract

We present Floquet calculations of the total rate for multiphoton ionization of atomic hydrogen by a coherent superposition of the second and third harmonics of a Nd:YLF (neodymium-doped yttrium-lithium-fluoride) laser Beld. The total rate depends little on the relative phase of the two 6elds in the range of intensity considered.PACS number(s): 32.80.Rm

Above-threshold multiphoton detachment ofH−by two-color laser fields: Angular distributions and partial rates

“…Further, the relative phase dependence of the total rates is more pronounced for the frequency ratio 1:3 than for 1:2 [4] and 2:3 [5] since all the pathways leading to a continuum states with the same energy interfere in the 1:3 case whereas a considerable pattern of uninterfering pathways exists for the other cases due to parity or energy restrictions [5]. The oscillatory ionization probability dependence on the relative phase with the maximum at 5 =0 and minimum at 5 = m was also reported by Pont, Proulx, and Shakeshaft [6] [7 -9], doubly excited states far above the ionization threshold can be safely ignored for moderately strong laser fields.…”

Photodetachment dynamics from closed‐shell anions in the presence of a bichromatic field

“…Theoretical studies of the discussed phenomenon for a number of atomic systems have been carried out both within the framework of a perturbation treatment of the electromagnetic interaction of the considered atomic system with a relatively weak bichromatic laser field 20–22 and within the framework of the so‐called Keldysh–Faisal–Reiss approach 23 and its various modifications 24 when the field of one or both is strong enough so that the interaction of a detached electron being in continuous spectrum states with its parent residual atomic core may be neglected. The case of a strong bichromatic field has been studied using various completely quantum mechanical numerical simulations of the photodetachment process for various schemes of transitions in atomic systems 25, 26. For a multi‐interacting particle system, it is a rather involved problem.…”

Photoelectron spectra in strong-field ionization by a high frequency field

“…Afterwards, a broad variety of perturbative [22,23,24,25] as well as non-perturbative results [26,27,28,29,30,31,32] has been obtained. In addition, extensive numerical investigations have also been performed [33,34,35,36,37,38,39,40].…”