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. Also, it was investigated how different laser beam profiles affect the probability distribution. These physical situations are analyzed for the valence electron of potassium atom exposed to a strong laser field in a wide range of intensities (1012 -1015 W/cm2). We use 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.