2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/87465We suggest that electron-laser interactions can give rise to resonance phenomena as the intensity varies. A new QED perturbation theory is developed, in which the coupling between an electron and the second quantized laser mode is treated nonperturbatively. We predict, for example, the above-threshold ionization rate shows peaks at intensities with integer ponderomotive parameter. Such quantum resonance effects may be exploited to calibrate laser intensities in appropriate range.4 pages, 1 figureAtomic PhysicsHigh Energy Physics - Theorytext