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.

In view of the rapid growth in both experimental and theoretical studies of multi-photon processes and multi-photon spectroscopy of atoms, ions and molecules in chemistry, physics, biology, materials science, etc., it is desirable to publish an advanced series of volumes containing review papers that can be read not only by active researchers in these areas, but also by those who are not experts but who intend to enter the field. The present series aims to serve this purpose. Each review article is written in a self-contained manner by the expert(s) in the area, so that the reader can grasp the knowledge without too much preparation.

This volume contains the lectures and communications presented at the NATO Advanced Research Workshop on "Atomic and Molecular Processes with Short Intense Laser Pulses" (NATO ARW 848/86). The workshop was held at Bishop's University, Lennoxville, Que, Canada, July 19-24, 1987, under the directorship of Prof. A.D. Bandrauk, Universite de Sherbrooke. A scientific committee made up of Dr. P. Corkum (Laser Physics, ~ational Research Council of Canada), Dr. P. Hackett (Laser Chemistry, National Research Council of Canada), Prof. S.C. Wallace (Dept. of Chemistry and Physics, University of Toronto), and Prof. F.H.M. Faisal (FakultHt fUr Physik, UniversitHt Bellefeld) was called upon to invite and organize eminent lectures in the fields of i) Coherence Phenomena in Atomic and Molecular Photoprocesses. ii) High Intensity Atomic and Molecular Phenomena. iii) Laser Chemistry The aim of the workshop was to bring together chemists and physicists in order to~iscuss and analyze the progress made in the use of short in tense laser pulses in understanding coherence phenomena and high intensity, nonlin~adiative effects in atomic and molecular systems.

Providing the chemical physics field with a forum for critical, authoritative evaluations in every area of the discipline, the latest volume of Advances in Chemical Physics continues to provide significant, up-to-date chapters written by internationally recognized researchers. This volume is essentially devoted to helping the reader obtain general information about a wide variety of topics in chemical physics. Advances in Chemical Physics, Volume 117 includes chapters addressing laser photoelectron spectroscopy, nonadiabatic transitions due to curve crossings, multidimensional raman spectroscopy, birefringence and dielectric relaxation in strong electric fields, and crossover formulae for Kramers Theory of thermally activated escape rates.