Resonance phenomena in the multiphoton ionization of excited atoms

Rutger B. Vrijen, Lambertus D. Noordam

G. A. Delone, Nikolai B. Delone, G. K. Piskova

Young Soon Kim

Nikolai B. Delone

The most important results of study of multiphoton ionization of atoms are reviewed. Discussions are presented of specific features of the process, theoretical methods of description of ionization of atoms in a strong light field, the basic principles of design of experiments in which intense laser radiation is used, results of investigation of direct and resonance processes of multiphoton ionization, and the mutual relation between multiphoton processes (multiphoton excitation and ionization) and various phenomena leading to perturbation of the spectrum of bound states of an electron in an atom under the influence of a strong light field.

Yu. I. Heller

S. Feneuille

The review describes and interprets the basic phenomena recently observed in the interaction between free atoms and laser radiation. Some of these have been known for a long time in magnetic resonance but in the optical range, the situation is strongly modified because of spontaneous emission and the Doppler effect. Therefore, particular attention is paid to resonance fluorescence and Doppler-free spectroscopy but without dwelling on applications. Transient effects are also discussed, but all the phenomena which characterize, not specifically the interaction between atoms and fields, but the free evolution of atoms after coherent excitation are ignored. Pulse propagation experiments are described in detail and multiphoton processes are considered, with special emphasis on Doppler-free multiphoton excitation and resonant multiphoton ionization.