Laser effects in photoionization. II. Numerical solution of coupled equations for atomic hydrogen

The time-dependent Schr\"odinger equation was solved numerically, as a set of coupled equations, for an electron moving in three spatial dimensions, bound initially in the ground state of a hydrogen atom, and acted upon by a linearly polarized, single-frequency, classical electromagnetic field, turned on abruptly at t=0. Characteristic photoionization times τPI were computed for a wide range of laser intensities, at a photon energy of 5 eV. Comparison was made with the predictions of two widely used analytic expressions for τPI. Emitted electron energy spectra and angular distributions were computed. The spectrum of radiation emitted during ionization was also determined.