Numerical method for calculating atomic spectra in strong laser fields

In this paper, a new theoretical method is suggested for calculating atomic emission spectra in strong laser fields. This numerical method based on diagonalization of the energy matrix of an atom in the electric field is free from limitations of perturbation theory and valid for a wide range of changes in the electric field strength and frequency. Within the framework of the suggested method, the ground-state shifts of He, Ne, Ar, and Kr atoms in a circularly polarized electric field are computed. Calculations are carried out for electric fields with strengths of 0.06 and 0.15 a.u. and frequencies from 10-4 to 0.057 a.u. In addition, the effect of ordering of the transition probabilities with respect to the magnetic quantum number M in the electric field is also investigated. The results obtained can be useful for correct interpretation of the experimental data and prediction of the behaviour of atomic emission spectra in strong laser fields.