Weakly and strongly bound electronic motion in a laser field

Stimulated by the need to solve numerically the time-dependent Schrodinger equation in the most efficient manner we study analytically the distributio n over angular momentum eigenstates of an initially Gaussian wavepacket in a linearly polarized laser field, evolving in time, both in momentum and le ngth gauge. Two extreme cases are examined in detail, namely when the laser field is either very strong or else very weak in comparison to the confini ng potential experienced by the wavepacket. These cases help identify the m ost advantageous choice of gauge for calculations on laser-driven atoms in a variety of circumstances.