Since their inception more than 2.5 years ago, photon correlation techniques for the spatial, temporal or spectral analysis of fluctuating light fields have found an ever-widening range of applications. Using detectors which re spond to single quanta of the radiation field, these methods are intrinsically digital in natnre and in many experimental situations offer a unique degree of accuracy and sensitivity, not only for the study of primary light sources themselves, but most particularly in the use of a laser-beam probe to study light scattering from pure fluids, macromolecular suspensions and laminar or turbulent flowing fluids and gases. Following the earliest developments in laser scattering by dilute macro nl01ecular suspensions, in, ... hich particle sizing was the main aim, and the use of photon correlation techniques for laser-Doppler studies of flow and tnrbuence. both of which areas were the subject of NATO ASls in Capri, Italy in 19; 3 and 19;6. significant advances have be('n made in recent years in many other areas. These were reflected in the topics covered in this NATO Advanced Research Workshop, which took place from August 2;th to 30th, 1 ) }6, at the Jagiellonian University, Krakow, Poland. These in cluded ('xperimental techniques. statist.ics and data reduction, colloids and aggregation, polymers, gels, liquid crystals and mixtures, protein solutions, critical pllf'nomena and dense media."

Based on a special ONR seminar, Photons and Quantum Fluctuations draws together discoveries in nonclassical or "silent" light for research workers and postgraduates in quantum optics. With nonclassical light, noise is reduced in amplitude below that expected by previous applications of the uncertainty principles. Historians of science who wish to ponder the philosophical implications of these developments may also find this a useful volume.

Based on a special ONR seminar, Photons and Quantum Fluctuations draws together discoveries in nonclassical or "silent" light for research workers and postgraduates in quantum optics. With nonclassical light, noise is reduced in amplitude below that expected by previous applications of the uncertainty principles. Historians of science who wish to ponder the philosophical implications of these developments may also find this a useful volume.

This book is unique in covering phenomena in photon- matter interactions in a unified way over a range of many orders in energy. The quantum field theoretic approach to the fully relativistic theory of quantum electrodynamics (QED) is presented together with the non- relativistic theory in both confined and unconfined geometries. The predictions of QED have been verified to a greater accuracy than any other physical theory. Moreover QED is a paradigm for other gauge theories and is presented in such a way that the generalisation to other gauge theories is natural. Gauge and Poincare symmetry properties and the non-existence of a photon wave function are thoroughly discussed. Starting from the Dirac equation the non-relativistic interaction of the electron with the electromagnetic field is derived as an effective Hamiltonian of multipole expansions. Much of quantum optics is based on the lowest order dipole approximation. From this point on the treatment of fully relativistic QED and quantum optics is done in parallel. Applications of perturbation theory such as Compton and Moller scattering and the theory photdetection are given. After the impressive successes of QED, the limitation of the theory and the necessity of electroweak theory and quantumchromodynamics are discussed. The remaining chapters are devoted to quantum optics inside cavaties. Various approaches to open systems such as master equations are discussed within the context of active systems (e.g. the laser) and passive systems. Semi- classical approximarions are shown to imply a rich non- linear dynamics including chaos for certain parameter regimes. The effect of fluctuations on such non-linear dynamics is also studied. The final chapter is devoted to highly non- classical states of the light field such as photon number, squeezed and two photon entangled states. The latter are studied for the important system of parametric down conversion and the localisation properties of photons are characterised in terms of asympotic tails in photodetection probabilities as a function of time delay. The range of the book has wider benefits. Workers in quantum optics will gain a deeper understanding of the foundations of their subject and field theorists will see concrete examples of open systems, which are beginning to impinge on fundamental theories.

Since their inception more than 2.5 years ago, photon correlation techniques for the spatial, temporal or spectral analysis of fluctuating light fields have found an ever-widening range of applications. Using detectors which re spond to single quanta of the radiation field, these methods are intrinsically digital in natnre and in many experimental situations offer a unique degree of accuracy and sensitivity, not only for the study of primary light sources themselves, but most particularly in the use of a laser-beam probe to study light scattering from pure fluids, macromolecular suspensions and laminar or turbulent flowing fluids and gases. Following the earliest developments in laser scattering by dilute macro nl01ecular suspensions, in, ... hich particle sizing was the main aim, and the use of photon correlation techniques for laser-Doppler studies of flow and tnrbuence. both of which areas were the subject of NATO ASls in Capri, Italy in 19; 3 and 19;6. significant advances have be('n made in recent years in many other areas. These were reflected in the topics covered in this NATO Advanced Research Workshop, which took place from August 2;th to 30th, 1 ) }6, at the Jagiellonian University, Krakow, Poland. These in cluded ('xperimental techniques. statist.ics and data reduction, colloids and aggregation, polymers, gels, liquid crystals and mixtures, protein solutions, critical pllf'nomena and dense media."