The birth of quantum electronics in the middle of the 20th century, and the subsequent discovery of the laser, led to new trends in physics and a number of photonic technologies. This volume is dedicated to Peter Franken, a pioneer of nonlinear optics, and includes papers by the founders of quantum electronics, Aleksandr Prokhorov, Nicholaas Bloembergen and Norman Ramsey. A number of papers are devoted to current problems in laser physics, written by well-known leaders in the international quantum optics and lasers community and their collaborators. The topics covered range from astronomy to nuclear and semiconductor physics, and from fundamental problems in quantum mechanics to applications in novel laser materials and nanoscience.

This book deals specifically with the manipulation of atoms by laser light, describing the focusing, channeling and reflection of atoms by laser fields. It also describes the potential fields required to cause the phase change of the wave function necessary for the atomic interactions to occur.

The laser as a source of coherent optical radiation has made it possible to investigate nonlinear interaction of optical radiation with atoms and mole cules. Its availability has given rise to new research fields, such as non linear optics, laser spectroscopy, laser photochemistry, that lie at the boundary between quantum electronics and physical optics, optical spectros copy and photochemistry, respectively. The use of coherent optical radiation in each of these fields has led to the discovery of qualitatively ne\~ effects and possibilities; in particular, some rather subtle effects of interaction between highly monochromatic light and atoms and molecules, in optical spec troscopy, have formed the bases for certain methods of so-called nonlinear, laser Doppler-free spectroscopy. These methods have made it possible to in 5 6 crease the resolution of spectroscopic studies from between 10 and 10 , lim 11 ited by Doppl er 1 i ne broadeni ng up, to about 10 ; at present some 1 abor atories are developing new techniques that have even higher resolution. The discovery and elaboration of the methods of nonlinear laser spectroscopy have resulted largely from contributions by scientists from many countries, in particular from the USA (Massachusetts Institute of Technology, Stanford Uni versity, National Bureau of Standards in Boulder, Harvard University, etc. ), the USSR (P. N. Levedev Institute of Physics, Institute of Semiconductor Phys ics in Novosibirsk, Institute of Spectroscopy, etc.

The conference "Laser Science and Technology" was held May 11-19, 1987 in Erice, Sicily. This was the 12th conference organized by the Internatio nal School of Quantum Electronics, under the auspices of the "Ettore Majorana" Center for Scientific Culture. This volume contains both the in vited and contributed papers presented at the conference, covering current research work in two areas: new laser sources, and laser applications. The operation of the first laser by Dr. Theodore Maiman in 1960 initia ted a decade of scientific exploration of new laser sources. This was fol lowed by the decade of the 1970s, which was characterized by "technology push" in which the discoveries of the 1960s were seeking practical applica tion. In the 1980s we are instead seeking "applications pull," in which the success and rapid maturing of laser applications provides both inspiration and financial resources to stimulate additional work both on laser sources and applications. The papers presented in these Proceedings attest to the great vitali ty of research in both these areas: New Laser Sources. The papers describe current developments in ultra violet excimer lasers, X-ray lasers, and free electron lasers. These new lasers share several characteristics: each is a potentially important coher ent source; each is at a relatively short wavelength (below 1 micrometer); and each is receiving significant development attention today."

Prefaces are usually written when a manuscript is finished. Having finished this book I can clearly see many shortcomings in it. But if I began to eliminate them I would probably write quite a different book in another two years; indeed, this has already happened once. In 1979, when I finished the first version of this book, it was much broader in scope and was to be titled "Laser Photochemistry." Corrections and additions to that unpublished manuscript gave rise to the present book with its revised title and more specific subject matter. I resolved to have it published in exactly this form, despite the fact that it concerns a dynamically developing field of research and will soon make way for other works. This book contains the basic ideas and results I have been developing with my colleagues, friends and students at the Institute of Spectroscopy, USSR Academy of Sciences, in the town of Troitsk since 1970. It deals with the interaction of light with atoms and molecules via multiple-phonon inter action. Nonlinear processes in the resonant interaction are used to illustrate the physical mechanisms involved and to indicate how these processes have led to modern applications such as isotope separation, detection of single atoms and molecules, and chemical and biochemical synthesis."

The optoacoustic method has by now an almost one-centurY-long history of appl ication in spectroscopy, but it was only with the advent of the laser that it became a convenient and effective method among the vast family of spectroscopy techniques. The great variety of these techniques is capable of tackling most diversified tasks, such as the achievement of a high sensitiv ity and a high spectral or temporal resolution. The optoacoustic method is one of the simplest and most versatile ways to attain a high sensitivity for both gaseous and condensed media. It is precisely for this reason that the method has found wide use, and that we have decided to publish a mono graph reviewing the information on this method available in the literature and gathered by us at the Institute of Spectroscopy during the past few years. We hope that such a systematic exposition of the material scattered throughout numerous scientific journals will be of use to many potential readers. The reader will undoubtedly notice the absence in our monograph of references to some recent works, but unfortunately, this is inevitable when the translation and publication of a book in a foreign language takes sev eral years. Nevertheless, we tried our best to cover the entire field from the material available to us, but unfortunately, some recent publications might be missing due to the time lag for the translation and publication in a language foreign to us."