QUANTUM OPTICS AND LASER EXPERIMENTS Edited by Sergiy Lyagushyn Quantum Optics and Laser Experiments Edited by Sergiy Lyagushyn Published by InTech Janeza Trdine 9, 51000 Rijeka, Croatia Copyright © 2011 InTech All chapters are Open Access distributed under the Creative Commons Attribution 3.0 license, which allows users to download, copy and build upon published articles even for commercial purposes, as long as the author and publisher are properly credited, which ensures maximum dissemination and a wider impact of our publications. After this work has been published by InTech, authors have the right to republish it, in whole or part, in any publication of which they are the author, and to make other personal use of the work. Any republication, referencing or personal use of the work must explicitly identify the original source. As for readers, this license allows users to download, copy and build upon published chapters even for commercial purposes, as long as the author and publisher are properly credited, which ensures maximum dissemination and a wider impact of our publications. Notice Statements and opinions expressed in the chapters are these of the individual contributors and not necessarily those of the editors or publisher. No responsibility is accepted for the accuracy of information contained in the published chapters. The publisher assumes no responsibility for any damage or injury to persons or property arising out of the use of any materials, instructions, methods or ideas contained in the book. Publishing Process Manager Marina Jozipovic Technical Editor Teodora Smiljanic Cover Designer InTech Design Team First published January, 2012 Printed in Croatia A free online edition of this book is available at www.intechopen.com Additional hard copies can be obtained from orders@intechweb.org Quantum Optics and Laser Experiments, Edited by Sergiy Lyagushyn p. cm. ISBN 978-953-307-937-0 free online editions of InTech Books and Journals can be found at www.intechopen.com Contents Preface IX Part 1 Theoretical Fundamentals: Problem of Observables 1 Chapter 1 Description of Field States with Correlation Functions and Measurements in Quantum Optics 3 Sergiy Lyagushyn and Alexander Sokolovsky Chapter 2 Nonclassical Properties of Superpositions of Coherent and Squeezed States for Electromagnetic Fields in Time-Varying Media 25 Jeong Ryeol Choi Chapter 3 Photon Localization Revisited 49 Peeter Saari Chapter 4 Fusion Frames and Dynamics of Open Quantum Systems 67 Andrzej Jamiołkowski Part 2 Quantum Phenomena with Laser Radiation 85 Chapter 5 Quantum Optics Phenomena in Synthetic Opal Photonic Crystals 87 Vasilij Moiseyenko and Mykhailo Dergachov Chapter 6 Resonant Effects of Quantum Electrodynamics in the Pulsed Light Field 107 Sergei P. Roshchupkin, Alexandr A. Lebed’, Elena A. Padusenko and Alexey I. Voroshilo Chapter 7 Cold Atoms Experiments: Influence of Laser Intensity Imbalance on Cloud Formation 157 Ignacio E. Olivares and Felipe A. Aguilar Preface The book covers a wide spectrum of research problems concerning quantum theory of light and experiments using its quantum properties. In reference literature one can find a number of definitions for the term “quantum optics” – from the sphere of phenomena revealing the quantum nature of light to the optics section dealing with statistical properties of emission. Such a contradictory situation reflects a complicated way of notion formation. Difficulties of the classical wave concept of light were the basis for formulating new quantum concepts of light emission, propagation, interaction and a new general concept – field concept of matter in the first quarter of the 20th century. In this sense we can speak about quantum optics whenever optical phenomena are considered from the position of quantum theory. That is especially true for the world of phenomena that can be discussed and understood only within the framework of quantum picture. The possibilities of optical experiments have been broadened fantastically by the invention of laser. Since lasers are quantum optical generators, the domain of experiments with laser emission seems to be close to quantum optics. At the same time, strong electromagnetic fields generated by lasers usually manifest their classical properties, so some analysis is necessary for including the observed phenomena into the field of quantum optics. In classical optics, correlation properties of light connected with the statistical nature of a real experiment were discussed in terms of the conception “coherence”. In the experiments of Hanbury Brown–Twiss with quantum detecting of light, the process of receiving an electromagnetic emission was considered a usual random process for the first time. Later on, the whole ideology of probability theory and stochastic processes was applied to optical phenomena using quantum detectors for analyzing the statistical (correlation) properties of electromagnetic fields in optics. It gives substantiation for quantum optics identification as a statistical theory of light. The editor was faced with different interpretations of quantum optics while analyzing the chapter proposals. Upon examining them, he reached the conclusion that all theoretical and experimental papers were welcome if they contributed to our understanding of light as a quantum phenomenon. The accepted approach was to speak about quantum optics in a wide sense, i.e. different phenomena demonstrating the quantum nature of light together with theoretical constructs applied to them; and in the narrow sense, i.e. the statistical theory of light processes and its incarnation with X Preface quantum detecting schemes. The present title of the book reflects its real contents and breadth of topics. The first section titled “Theoretical Fundamentals: Problem of Observables” includes four chapters united in the search for adequate mathematical apparatus for quantum electromagnetic field state description, taking into account experimental research possibilities. The first chapter “Description of Field States with Correlation Functions & Measurements in Quantum Optics” by Dr. S. Lyagushyn and Prof. A. Sokolovsky incorporates the discussion of basic approaches to field investigation in quantum optics. Since measurements with quantum detectors lead to Glauber correlation function and the Glauber-Sudarshan P-function is the most consumable tool for practical field description, such functions are regarded as an optimal way for field diagnostics. Then the Bogolyubov reduced description is constructed for a medium consisting of two-level emitters (the Dicke superfluorescence phenomenon) and plasma-field system. In such way, the connection is made using simultaneous correlation functions of field amplitudes for system evolution description, constructing differential equations for them, and coming to a quasiequilibrium statistical operator for system constituents at large times, the statistical operator permitting correlation function calculation. The necessity of considering binary correlation of field is substantiated. Such kinds of electrodynamics in media imply obtaining certain material equations. Various forms of correlation description are presented: one- particle density matrix, Wigner distribution function, and correlation functions of Glauber type. Correlation functions in the theory of radiation transfer and corresponding equations are considered. A way to field evolution description on the basis of a generating functional and Glauber-Sudarshan distribution connected with it is proposed. The second chapter is “Nonclassical Features of Superpositions of Coherent and Squeezed States for Electromagnetic Fields in Time-Varying Media” by Prof. Choi Jeong Ryeol. The author is interested in light behavior in media with varying characteristic parameters, the situation promising several interesting applications. A special method of field quantization based on the invariant operator theory is used. Thus deriving quantum solutions for time-dependent Hamiltonians becomes possible. The exact wave functions for the system with time-varying parameters can be derived in Fock, coherent, and squeezed states. Then superpositions of quantum states are considered in the search for nonclassical properties (high-order squeezing, subpoissonian photon statistics, and oscillations in the photon-number distribution). Such analysis is based on the Wigner distribution function, allowing us to know the phase space distribution connected to a simultaneous measurement of position and momentum. The Wigner distribution function is regarded as quasiprobability distribution function and is widely used in explaining intrinsic quantum features that have no classical analogue. The third chapter “Photon Localization Revisited” by Prof. P. Saari is devoted to the intriguing problem that is traditionally under discussion in literature on quantum . QUANTUM OPTICS AND LASER EXPERIMENTS Edited by Sergiy Lyagushyn Quantum Optics and Laser Experiments Edited by Sergiy Lyagushyn. Saari Chapter 4 Fusion Frames and Dynamics of Open Quantum Systems 67 Andrzej Jamiołkowski Part 2 Quantum Phenomena with Laser Radiation 85 Chapter 5 Quantum Optics Phenomena in Synthetic. complex conjugated functions and coming to positive- and negative-frequency parts of field operators. Such expressions will be shown later on. Quantum Optics and Laser Experiments 6 Physical