“…(8) has been widely used to describe the emitted electron immersed in the laser field. For example the Strong Field Approximation (SFA) [12,13,17,22], the Coulomb-Volkov Approximation (CVA) [5,8,11,15,23] and the semiclassical application of the Simple Man's Model (SCM) [3,4,6] employ the non-stationary Volkov state as final wavefunction. The use of length gauge for the perturbation potential, i.e.…”