Phenomenological factorization of high harmonic generation (HHG) and above threshold ionization (ATI) yields in terms of rescattered electron wavepackets (EWP) and free-atom parameters (such as the photo-recombination and elastic electron scattering cross sections), suggested by C.D. Lin and co-workers in 2008 based on numerical solution of the time-dependent Schrödinger equation (TDSE), is extremely useful for analyzing atomic dynamics effects and extracting atomic parameters from cross sections of strong-field processes. However, the explicit form of the electron wavepackets in this factorization is a “black box”.

Recently, we have developed a theoretical model for an analytical description (in the low-frequency approximation) of the high-energy part of rescattering plateaus in strong-field atomic processes. In this report, I will present a brief review of our theoretical approach and of our detailed analytic expressions for cross sections of a number of laser-induced (HHG and ATI) and laser-assisted processes, such as laser-assisted electron-atom scattering and radiative electron recombination (LAES and LAER).

Factorization formulas, an explicit form for the EWPs, and comparisons with TDSE results (where possible) will be discussed for the following processes: HHG and ATI in a monochromatic field, as well as in a few-cycle laser pulse, and LAES and LAER in a linearly polarized laser field. Resonance phenomena in HHG, LAES, and LAER also will be reviewed.