My aim in this book has been to give an account of the theoretical methods of analysis of multiphoton processes in atomic physics. In this account I have emphasized systematic methods as opposed to ad hoc approaches. Both perturbative and nonperturbative methods are presented with il lustrative results of concrete applications. The perturbation theory is the primary tool of analysis of nonresonant multiphoton processes. It is developed here in conjunction with a diagrammatic language and is also renormalized to free it from the unwanted divergences which accompany the ordinary treatment when higher-order corrections are considered. The nonperturbative methods (i.e., methods other than that of power series ex pansion in the field strength) become particularly important for consistent treatments of problems involving, for example, intermediate resonances, high field strengths, and finite pulse duration. The specifically nonpertur bative methods for multiphoton transitions are presented in Chapters 6-11. The methods of resolvent equations and of effective Hamiltonians are developed for both the stationary and the time-dependent fields. The densi ty matrix method is presented in conjunction with the problems of relaxa tion and of fluctuating fields. The Floquet theory is presented both in the energy domain and in the time domain. Also treated are the methods of continued fractions, recursive iterative equations, and chain Hamiltonians.

This book presents a detailed, modern description of the ionization of atoms by strong laser radiation. The authors present descriptions of processes occurring in atoms under the action of strong electromagnetic radiation, in particular, the shift, broadening, and mixing of atomic states. The topics include tunneling ionization, above-threshold ionization, ionization of multiply charged ions, resonance-enhanced ionization, super-intense radiation fields, and properties of Rydberg states strongly perturbed by laser radiation.

The chapters of this volume represent the invited papers delivered at the 3rd International Conference on Multiphoton Processes (ICOMP III) held in Iraklion, Crete, Greece, September 5-11, 1984. The invited papers at a conference like ICOMP cannot possibly cover the whole field which has grown to immense proportions in recent years, overlapping with such diverse areas as atomic and molecular spectroscopy, plasma physics, nonlinear optics, quantum optics, etc. We believe these contributions represent that part of the research activity which has been attracting the most interest in the past year or so, as well as reviews of some of the more established topics. Even within this scope, and given the confines imposed by the fi nite duration of a conference, important and timely topics are inevitably left out. But then, there will be ICOMP IV. The collection of articles in this volume, combined with extensive ref erences to related work given by the authors, should provide an introduc tion to the major problems of the field and its state of the art. The chapters have been arranged according to thematic proximity, beginning with atoms, and continuing on with molecules and surfaces. This classi fication, however, would not cover all the subject matter even within the limited scope of the conference and of this volume.

Recent advances in ultrashort pulsed laser technology have opened new frontiers in atomic, molecular and optical sciences. The 12th International Conference on Multiphoton Processes (ICOMP12) and the 3rd International Conference on Attosecond Physics (ATTO3), held jointly in Sapporo, Japan, during July 3-8, showcased studies at the forefront of research on multiphoton processes and attosecond physics. This book summarizes presentations and discussions from these two conferences.

This volume of proceedings of the latest International Conference on Multiphoton Processes provides a timely report on the latest work on the interaction of lasers with atoms and molecules, including short laser pulses, intense fields, stabilization, high harmonic generation, coherent control of reactions and reports from leading laboratories.

Multiphoton ionization of atoms in intense laser-light fields is gaining ground as a spectroscopic diagnostic tool. In this volume, Delone and Krainov present their and others' theoretical description of the process occurring in atoms under conditions of multi-photon impacts, in particular, the shift, broadening, and mixing of electronic states which complicate the interpretation of spectra. The topics of individual chapters include tunneling ionization, above-threshold ionization, ionization of multiply charged ions, resonance-enhenced ionization, super-intense radiation fields, and properties of Rydberg states in strong fields.

In view of the rapid growth in both experimental and theoretical studies of multiphoton processes and multiphoton spectroscopy of atoms, ions, and molecules in chemistry, physics, biology, materials sciences, etc., it is desirable to publish an Advanced Series that contains review papers readable not only by active researchers in these areas, but also by those who are not experts in the field but who intend to enter the field. The present series attempts to serve this purpose. Each review article is written in a self-contained manner by experts in the area so that the readers can grasp the knowledge in the area without too much preparation. This volume will be useful not only to active researchers but also to other scientists in the area of biology, chemistry, materials science, and physics.

This volume presents recent progress and perspectives in multi-photon processes and spectroscopy of atoms, ions, molecules and solids. The subjects in the series cover the experimental and theoretical investigations in the interdisciplinary research fields of natural science including chemistry, physics, bioscience and material science. This volume is the latest volume in a series that is a pioneer in compiling review articles of nonlinear interactions of photons and matter. It has made an essential contribution to the development and promotion of the related research fields. In view of the rapid growth in multi-photon processes and multi-photon spectroscopy, care has been taken to ensure that the review articles contained in the series are readable not only by active researchers but also those who are not yet experts but intend to enter the field.

This volume presents recent progress and perspectives in multi-photon processes and spectroscopy of atoms, ions, molecules and solids. The subjects in the series cover the experimental and theoretical investigations in the interdisciplinary research fields of natural science including chemistry, physics, bioscience and material science.This volume is the latest volume in a series that is a pioneer in compiling review articles of nonlinear interactions of photons and matter. It has made an essential contribution to the development and promotion of the related research fields. In view of the rapid growth in multi-photon processes and multi-photon spectroscopy, care has been taken to ensure that the review articles contained in the series are readable not only by active researchers but also those who are not yet experts but intend to enter the field.

In view of the rapid growth in both experimental and theoretical studies of multiphoton processes and multiphoton spectroscopy of atoms, ions and molecules in many interdisciplinary fields, an Advanced Series that contains review papers readable not only to active researchers in these areas but also to those who are not experts in the field but intend to enter the field is very necessary. This series attempts to serve this purpose. Each review article is written in a self-contained manner by the experts in the area so that the readers can grasp the knowledge in the area without too much preparation. The collection of topics in this volume will prove useful, valuable and stimulating not only to active researchers but also to other scientists in the areas of biology, chemistry, materials science and physics.