A STATIONARY TREATMENT OF TIME-DEPENDENT HAMILTONIAN BY THE MANY-MODE FLOQUET FORMALISM AND ITS APPLICATION TO THE STUDY OF EFFECTS OF LASER-PULSES IN MULTIPHOTON PROCESSES

A general stationary nonperturbative treatment of time-dependent Hamiltonian system is presented by extending the many-mode Floquet formalism and a feature of initial value problem of the Schrodinger equation. The method is applied to the first analytical treatment of the effects of pulsed laser fields in multiphoton processes. Explicit analytical formulas for multiphoton transition probabilities and a generalized (multiphoton) pulse area concept for two-level quantum systems driven by pulse laser fields are obtained for the first time.