Many-photon excitation of spherically symmetric molecules in an infrared laser field by weakly forbidden ΔR≠0, Δn≠0 vibrational–rotational transitions

Abstract

An analysis is made of a model of multistage excitation of triply degenerate vibrations of spherically symmetric molecules in a strong infrared laser field. This involves allowing for weakly forbidden ?R?0, ?n?0 transitions. It is shown that as a result of these transitions, a system of up to several dozen multistage resonances is established within the absorption band. These resonances cover a group of rotational levels with different values of J (up to 10?20 values) and ensure that a considerable proportion of the molecules is excited to high vibrational states (up to ? = 10?15).