in intense laser fields: mechanisms for enhanced ionization in the multiphoton regime

Abstract
Multiphoton ionization rates from the lower states of are calculated within the non-perturbative Floquet framework. The mechanisms for enhanced ionization in the multiphoton regime are studied as a function of laser frequency, laser intensity and internuclear separation. We contrast these mechanisms with those that apply in the DC-like tunnelling regime. Our results are compared with those of other calculations where these are available. The intensity range of validity of the 2-electronic state model is explored. Finally, the question of laser-induced adiabatic stabilization is discussed.