Theoretical Study On The Ionization Of Hydrogen Atom In An The Intense Laser Field

The advent of ultra-short, super-intense laser provides a new extremely experimental condition in the interaction of light with material. The ionization of atoms under the intense laser fields is one of important process with interaction of laser with atom. Using the ionization of phenomena of atoms interacting with intense laser fields, it make people realize atom's nature,and at the same time it can be used to research of ultra-fast process within molecule and atom. So to study the ionization of atoms under the intense laser fields is very interesting and attractive.In the theoretical study of photoionization of atoms in strong laser fields , The methods mainly are numerical solution the time-dependent Schr(?)dinger equation(TDSE), the strong field approximation(SFA) and ADK approximation. The numerical solution TDSE needs much calculation and requires strictly for computer, ADK model adapts in the tunnel ionization regime and the ionization of atoms whose atomic number more larger in strong laser fields, and it is unfit for the ionization of atoms whose atomic number more smaller in strong laser fields. Thus, Strong field approximation is frequently used. The calculation of this method is simple and definite. However, this method neglects the effect of parent ion to electron, and the results is poor in some instance. So it's necessary to introduce Coulomb correction to SFA. In order to review the relation of the ionization of atoms along with different laser's parameter is introduced by Krainov, In this paper we calculate the ionization energy spectra of hydrogen atom in the linear polarization laser fields of different wavelength by using the approach of traditional SFA which is in length gauge and in velocity gauge. Compared the results with those of direct numerical solution of time-dependent Schr(?)dinger equation. Then in this paper we calculate the total ionization probability change along with laser wavelength and laser intensity and the ionization energy spectra of hydrogen atom in the linear polarization laser fields of different wavelength by using the approach of traditional SFA and SFA with Coulomb correction. Compared the energy spectra with those of direct numerical solution of time-dependent Schr(?)dinger equation, it is shown that the results of SFA with Coulomb correction are in good agreement with those of direct numerical solution of time-dependent Schr(?)dinger equation at longer laser wavelength .