Above-threshold ionisation and electron scattering in intense laser fields

Abstract

The authors derive equations describing the non-resonant multiphoton ionisation of atoms or electron scattering in the presence of a strong laser field. They include both pure diagonal and off-diagonal coupling of continuum states. Their equations, in certain limits, reduce to the ones previously studied. They present some numerical results concerning angular distributions of photoelectrons in above-threshold ionisation and energy spectra in electron scattering.