In this chapter we discuss several ways in which laser physics makes contact with other fields and contributes to them. In Sec. 21-1 we mention a few sub jects that have been laser dominated, for example, nonlinear optics and light scattering. In Secs. 21-2, 21-3, and 21-4 we outline recent research ef forts which, in our opinion, provide good examples of how the techniques ap plied extensively in the laser analysis may be profitably applied to other prob lems in nonequilibrium quantum statistical mechanics. These problems also involve open systems and are influenced by nonlinear coherent and inco herent events. It is reasonable, then, to expect that the techniques which have been extensively studied and applied to problems such as the laser will have wide application in other areas. Specifically, three problems have been chosen for presentation here: a. A philosophical interpretation of laser “quasimodes” (Appendix B) in terms of the “true” modes of the universe.
In this chapter we discuss several ways in which laser physics makes contact with other fields and contributes to them. In Sec. 21-1 we mention a few sub jects that have been laser dominated, for example, nonlinear optics and light scattering. In Secs. 21-2, 21-3, and 21-4 we outline recent research ef forts which, in our opinion, provide good examples of how the techniques ap plied extensively in the laser analysis may be profitably applied to other prob lems in nonequilibrium quantum statistical mechanics. These problems also involve open systems and are influenced by nonlinear coherent and inco herent events. It is reasonable, then, to expect that the techniques which have been extensively studied and applied to problems such as the laser will have wide application in other areas. Specifically, three problems have been chosen for presentation here: a. A philosophical interpretation of laser “quasimodes” (Appendix B) in terms of the “true” modes of the universe.
This book attempts to bridge the enormous gap between introductory quantum mechanics and the research front of modern optics and scientific fields that make use of light in one step. Hence, while it is suitable as a reference for the specialist in quantum optics, it also targets the nonspecialists from other disciplines who need to understand light and its uses in research. With a unique approach it introduces a single analytic tool, namely the density matrix, to analyze complex optical phenomena encountered in traditional as well as cross‐disciplinary research. It moves swiftly in a tight sequence from elementary to sophisticated topics in quantum optics, including laser tweezers, laser cooling, coherent population transfer, optical magnetism, electromagnetically induced transparency (EIT), squeezed light, and cavity quantum electrodynamics (QED). A systematic approach is used that starts with the simplest systems – stationary two‐level atoms – then introduces atomic motion, adds more energy levels, and moves on to discuss first‐, second‐, and third‐order coherence effects that are the basis for analyzing new optical phenomena in incompletely characterized systems. Unconventional examples and original problems are used to engage even seasoned researchers in exploring a mathematical methodology with which they can tackle virtually any new problem involving light. An extensive bibliography makes connections with mathematical techniques and subject areas which can extend the benefit of each section to guide readers further. The steady progression from “simple” to “elaborate” makes the book accessible not only to students from traditional subject areas that make use of light (physics, chemistry, electrical engineering, and materials science), but also to researchers from the “hyphenated” subjects of modern science and engineering: the biophysicists using mechanical effects of light, photochemists developing coherent control for rare species detection, biomedical engineers imaging through scattering media, electromechanical engineers working on molecular design of materials for electronics and space, electrical and computer engineers developing schemes for quantum computation, cryptography, frequency references, and so on. To try to identify techniques and ideas that are universal enough to be applied across the bewildering landscape of research on intersecting boundaries of emerging modern disciplines is a great challenge of out time. “Lectures on Light” offers selected insights on quantum dynamics and quantum theory of light for exactly this purpose.
This book bridges the gap between introductory quantum mechanics and the research front of modern optics and scientific fields that make use of light. While suitable as a reference for the specialist in quantum optics, it also targets non-specialists from other disciplines who need to understand light and its uses in research. It introduces a single analytic tool, the density matrix, to analyze complex optical phenomena encountered in traditional as well as cross-disciplinary research. It moves swiftly in a tight sequence from elementary to sophisticated topics in quantum optics, including optical tweezers, laser cooling, coherent population transfer, optical magnetism, electromagnetically induced transparency, squeezed light, and cavity quantum electrodynamics. A systematic approach starts with the simplest systems—stationary two-level atoms—then introduces atomic motion, adds more energy levels, and moves on to discuss first-, second-, and third-order coherence effects that are the basis for analyzing new optical phenomena in incompletely characterized systems. Unconventional examples and original problems are used in exploring a mathematical methodology which can tackle virtually any new problem involving light. The steady progression from “simple” to “elaborate” makes the book accessible not only to students from traditional subject areas that make use of light, but also to researchers such as biophysicists using mechanical effects of light; photochemists developing coherent control for rare species detection; biomedical engineers imaging through scattering media; electromechanical engineers working on molecular design of materials for electronics and space; electrical and computer engineers developing schemes for quantum computation, cryptography, frequency references, and the like.
This book presents a systematic account of optical coherence theory within the framework of classical optics, as applied to such topics as radiation from sources of different states of coherence, foundations of radiometry, effects of source coherence on the spectra of radiated fields, coherence theory of laser modes, and scattering of partially coherent light by random media. The book starts with a full mathematical introduction to the subject area and each chapter concludes with a set of exercises. The authors are renowned scientists and have made substantial contributions to many of the topics treated in the book. Much of the book is based on courses given by them at universities, scientific meetings and laboratories throughout the world. This book will undoubtedly become an indispensable aid to scientists and engineers concerned with modern optics, as well as to teachers and graduate students of physics and engineering.
The previous chapters contain many examples of the successful application of quantum mechanics to the solution of real physical problems. These represent only a small sample of the wide range of experimental results, spanning just about all areas of physics and chemistry and beyond, that have been successfully explained by quantum theory. So far at least, no quantum-mechanical prediction has been experimentally falsified. Despite these successes, however, many scientists have considered the basic conceptual framework of the subject to be unsatisfactory, and repeated attempts have been made to reinterpret quantum mechanics, or even replace it with a different theory whose philosophical and conceptual basis could be considered more acceptable. In the present chapter we shall explain the reasons for this dissatisfaction and outline some of the reinterpretations and alternative approaches that have been devised. Inevitably many of the questions that arise in this area are matters of opinion rather than fact and, for this reason, some physicists consider that they belong more properly to the realm of philosophy than of physics. However, the conceptual basis of quantum mechanics is so fundamental to our whole understanding of the nature of the physical universe that it should surely be important for physicists to understand the nature of the problems involved, if nothing else.1,2 16.1 THE CONCEPTUAL PROBLEMS In this section we outline some of the main areas of difficulty with a view to more detailed discussion later in the chapter.
This book treats the interaction of radiation with matter, particular attention being paid to the laser. Knowledge is assumed of the usual half-year introduction of quantum mechanics found in undergraduate physics curricula. The material can be covered in two semesters, or, alternatively, the first part (Chaps 1-13) can be used as a one-semester course in which quantum mechanical aspects of the electromagnetic field are ignored. Each chapter is accompanied by problems that illustrate the text and give useful (occasionally new) results. Existing laser media are intrinsically quantum mechanical and are most easily studied with the quantum theory. Understanding the laser along these lines enlivens one's understanding of quantum mechanics itself. In fact, the material constitutes a viable, applied alternative for the usual second and third semesters of quantum mechanics.
The field of quantum optics has progressed rapidly in the last twenty five years with the advent of the laser. Over much of this period the phenomena studied could be described adequately by semiclassical treatments. Quite recently however, there has been a revival of interest in genuinely quantum mechanical effects. The Malvern Symposium of December 1985 brought together world experts for a meeting which concentrated largely on these quantum effects. The presentations in this unique meeting combine review material with the very latest results and so will be of value to students of quantum optics and measurement theory at all levels. The first articles cover the exciting topic of the generation of squeezed states of light in the laboratory, and their possible uses. Experimental success has been long sought and very recently attained. The reader will find presented the state of the art in this field. Next to lasing itself, optical bistability has been the most widely studied phenomenon in quantum optics, largely for its technological promise. However, it also provides a fundamental system to study quuantum effects. Recent theoretical studies of optical bistability with small numbers of atoms are surveyed. In such situations quantum features such as antibunching become significant, and the articles in this volume should be a guide to those venturing into this challenging area. In other articles discussions of fluctuations from other noise sources and instabilities in optical bistabilty are presented in a clear and interesting way. Perhaps the least classical state on quantum optics is that describing a single photon. Recent experiments which produce such states are reviewed. A theoretical review of the photon together with some new material is given which delves deeply into relativistic quantum field theory in order to describe the concept of weakly localised photon states. The material here is very rarely presented in the context of quantum optics. The history of the theory of the quantum fluctuations in a laser is then reviewed. An off-shoot of this theory is the study of quantum chaos in dissipative systems and recent results in this new area are given in a succeeding article. There are further stimulating articles on Rydberg atom systems and quantum electrodynamics. The volume ends with an entertaining and incisive study of quantum measurement problems, such as the Schrodinger cat papadox, using concepts and measuring devices found in quantum optics.other_titles