COULOMB CORRECTIONS IN ABOVE-THRESHOLD IONIZATION IN A BICHROMATIC LASER FIELD

We calculate the total ionization rate as a function of the kinetic en ergy of electrons ionized by a bichromatic laser field in an above-thr eshold ionization process. An improved Keldysh-Faisal-Reiss model, whi ch includes the Coulomb effects of the residual ions on the ionized el ectron, is used. We compare the results obtained using the length and the velocity gauge. In the case of the bichromatic laser field the pha se-dependent effects are observed and a comparison with recent experim ents is presented. A classical analysis of the rescattering cut-off la ws in a bichromatic laser field is also given.