Non-exponential tunneling ionization probability distribution as a function of different laser beam profiles

Abstract

In this paper, we discussed the probability distribution of exponential and non-exponential tunneling ionization of atoms, taking into account that the tunneling is not instantaneous, but requires a very short time interval. We also investigated how different laser beam profiles affected the probability distribution. These physical situations were analyzed for the valence electron of a potassium atom exposed to a strong laser field in a wide range of intensities (1012 ¡ 1015 W/cm2). We used the ADK theory formalism to compute probability distributions. The results demonstrate that the probability distribution in the non-exponential mode has a significantly lower value than in the exponential mode, calculated under the same conditions. We showed that various laser beam profiles on these probability distributions produce different tunneling time intervals.