Download or read book Interaction d un grand nombre de solitons dans un laser fibre written by Adil Haboucha and published by . This book was released on 2008 with total page 158 pages. Available in PDF, EPUB and Kindle. Book excerpt: Un laser à fibre de puissance dans une configuration à gestion de dispersion a été réalisé. Le laser est à verrouillage de modes passif par Rotation Non-Linéaire de la Polarisation (RNLP). La disponibilité de fortes puissances de pompage nous a permis de générer une grande diversité de régimes à impulsions multiples. Ces régimes multi-impulsionnels sont caractérisés par des dynamiques riches et variées : multi-stabilité et phénomène d'hystérésis ; évolution analogue à une transition de phase de la matière ; génération d'un gaz, d'un liquide, d'un colloïde et d'un cristal de solitons . . . etc. Les expériences ont été réalisées avec un laser à fibre à double gaine dopée à l'erbium. La dispersion totale de la cavité est ajustée par un tronçon de fibre à dispersion décalée. Le laser fonctionne soit en régime à impulsion étirée (dispersion totale normale) soit en régime solitonique (dispersion totale anormale). Sur le plan théorique et pour mieux comprendre le fonctionnement et les dynamiques inhérentes à notre système, deux modèles ont été développés. Nous donnons une analyse théorique détaillée de la génération d'un réseau de solitons liés ("cristal" de solitons). Cette structuration spontanée est décrite théoriquement au moyen d'une approche multi-échelles de la dynamique du gain : l'évolution d'un petit excès de gain est responsable de la stabilisation d'un train périodique d'impulsions, alors que l'évolution lente de la valeur moyenne du gain explique la longueur finie de ce train de solitons, qui n'est à cette échelle que quasi-périodique. Cette analyse permet de calculer le nombre d'impulsions formant le train à partir des paramètres physiques du laser.
Download or read book Manipulation d un grand nombre de solitons dissipatifs dans les lasers fibre written by Alioune Niang and published by . This book was released on 2014 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Ce travail est consacré à l'étude des interactions d'un grand nombre de solitons dans un laser à fibre dopée erbium/ytterbium. Les impulsions interagissent entre elles et se structurent pour former des distributions plus ou moins organisées. Deux cavités ont été réalisées, l'une basée sur la rotation non-linéaire de la polarisation (RNLP) et l'autre sur le miroir optique à boucle non-linéaire (NOLM) en configuration de laser en forme de huit. Avec la RNLP, nous nous sommes intéressés d'abord à une distribution où les impulsions sont liées (cristal de solitons). Ce cristal, stable pour des puissances moyennes, devient instable lorsque la puissance augmente : il se disloque. Les solitons se réorganisent pour former un régime de verrouillage harmonique (HLM) de 50 cristaux. Nous avons ensuite cherché s'il était possible de contrôler les distributions de solitons par l'injection d'une composante continue externe. Nous avons montré que le HLM peut être forcé par l'injection de cette composante. Nous avons développé deux approches afin de modéliser un laser verrouillé en phase et soumis à l'injection d'une composante continue, l'une est scalaire et l'autre vectorielle. Ces modèles démontrent que le signal injecté peut modifier les interactions entre les solitons. Enfin, le NOLM a permis d'observer plusieurs dynamiques : pluie de solitons, gaz de solitons, liquide de solitons, poly-cristal de solitons, multi-cristal de solitons, cristal de solitons, états liés et verrouillage harmonique d'états liés. Ce laser a permis également d'observer une émission laser continue et impulsionnelle autour de 1600 nm.
Download or read book Interactions de solitons dans les lasers fibre written by Michel Olivier and published by . This book was released on 2008 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Au cours de nos recherches, nous avons travaillé sur deux types de lasers à fibre : le laser à solitons ainsi que le laser à impulsions étirées. Les impulsions (ou solitons) produites par de tels lasers possèdent une durée de l'ordre de cent femtosecondes. Il est connu qu'une augmentation de la puissance pompe dans de telles cavités favorise la formation d'impulsions multiples. Ces impulsions interagissent entre elles en raison de la non-linéarité inhérente aux fibres optiques formant la cavité. Nos travaux portaient donc sur l'étude de ces interactions de solitons aux niveaux expérimental et théorique. Dans le cas du laser à solitons, nous montrons que deux types d'interaction existent entre les solitons. Le premier est une interaction par recouvrement direct basée sur la modulation croisée de phase et d'amplitude qui permet la formation d'un état lié ultra-rapproché (500 fs) de solitons. Le deuxième est une interaction par l'entremise des ondes dispersives émises par les solitons qui mène à la formation de plusieurs états liés de solitons avec des séparations de l'ordre de quelques picosecondes. Nous montrons que le gain détermine quel type d'interaction forme les états liés dans une cavité laser donnée. Nous étudions ensuite l'effet de la dispersion d'ordre trois sur ces deux types d'interaction et montrons, qu'en raison de l'asymétrie des résonances spectrales de Kelly, une seule résonance dominante gère l'interaction par les ondes dispersives. Dans le cas du laser à impulsions étirées, nous obtenons un seul état lié. Nous montrons que cet état lié est attribuable à une interaction non cohérente qui vient en fixer la séparation. Cette interaction se produit par l'entremise de la modulation de phase et d'amplitude croisée au moment où les deux solitons se recouvrent en leur point d'étirement maximal dans la cavité. Lorsque plus de deux solitons sont présents dans la cavité, nous obtenons des cas dynamiques pour lesquels un groupe de deux solitons et un soliton unique entrent en collision. Nous sommes en mesure d'expliquer ces comportements à l'aide de deux mécanismes : l'autodérive de fréquence et la dérive croisée de fréquence, induites toutes deux par l'effet Raman.
Download or read book Solitons in Optical Fiber Systems written by Mario F. S. Ferreira and published by John Wiley & Sons. This book was released on 2022-06-21 with total page 404 pages. Available in PDF, EPUB and Kindle. Book excerpt: Solitons in Optical Fiber Systems Discover a robust exploration of the main properties and behaviors of solitons in fiber systems In Solitons in Optical Fiber Systems, distinguished researcher Dr. Mário F. S. Ferreira delivers a thorough treatment of the main characteristics of solitons in optical fiber communication systems and fiber devices, paying special attention to stationary and pulsating dissipative soliton pulses. The book discusses the technical aspects associated with the physical background and the theoretical description of soliton characteristics under different conditions. The author employs numerical analyses and variational approaches to describe soliton evolution and describes the phenomenon of supercontinuum generation and various solitonic effects observed in highly nonlinear fibers, like photonic crystal fibers. Readers will learn about different applications of fiber solitons in transmission systems, fiber lasers, couplers, and pulse compression schemes, as well as complex Ginzburg-Landau equations, which are used to model different types of dissipative systems. The book also includes: A thorough introduction to solitons, including the linear and nonlinear effects of a wave, the discovery of solitary waves, and the discovery of solitons in optical fibers An exploration of fiber dispersion and nonlinearity, including optical fiber dispersion, the pulse propagation equation, and the impact of fiber dispersion Practical discussions of nonlinear effects in optical fibers, including self-phase modulation, cross-phase modulations, four-wave mixing, and stimulated raman scattering In-depth treatments of solitons in optical fibers, including modulation instability, dark solitons, bistable solitons, XPM-paired solitons, and the variational approach Perfect for senior undergraduate and graduate students in courses dealing with fiber-optics technology, Solitons in Optical Fiber Systems is also an ideal resource for engineers and technicians in the fiber-optics industry and researchers of nonlinear fiber optics.
Download or read book Journal de physique written by and published by . This book was released on 2006 with total page 772 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Solitons sombres et ondes dispersives dans les fibres optiques written by Tomy Marest and published by . This book was released on 2018 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Cette thèse a pour objectif l'étude expérimentale de la propagation de solitons sombres temporels aux abords de la longueur d'onde de dispersion nulle d'une fibre optique. Dans un premier temps, nous nous concentrons sur la génération d'ondes dispersives par des solitons sombres. Pour cela, plusieurs techniques de génération de solitons sont mises en oeuvre. La première, basée sur la collision de deux impulsions laser, permet de générer un train de quasi-solitons sombres. Ainsi, en fonction du nombre de solitons composant le train et de la puissance en entrée de la fibre, nous observons l'émission d'une seule ou de plusieurs ondes dispersives ainsi que la génération de supercontinua spectraux. La deuxième technique de génération de solitons sombres mise en place utilise un ensemble de deux façonneurs d'ondes optique. Au moyen de mesures spectrales et de corrélation croisée, nous montrons que celle-ci permet la génération de solitons sombres isolés dont la longueur d'onde, la phase, la profondeur et la durée peuvent être ajustées précisément. Nous montrons alors que la variation de ces paramètres induit une variation de la longueur d'onde des ondes dispersives émises. Nous étudions dans un deuxième temps la collision entre un soliton sombre et une onde dispersive. En réemployant la technique précédente, nous générons simultanément le soliton sombre et l'onde dispersive dans une fibre optique. Nous montrons alors théoriquement, numériquement et expérimentalement, que la collision mène à un décalage en fréquence de l'onde dispersive incidente suivant une relation d'accord de phase spécifique mettant en jeu la profondeur du soliton et la longueur d'onde de l'onde dispersive.
Download or read book Physics of Solitons written by Thierry Dauxois and published by Cambridge University Press. This book was released on 2006-03-09 with total page 435 pages. Available in PDF, EPUB and Kindle. Book excerpt: This textbook gives an instructive view of solitons and their applications for advanced students of physics.
Download or read book The Role of Topology in Materials written by Sanju Gupta and published by . This book was released on 2018 with total page 297 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book presents the most important advances in the class of topological materials and discusses the topological characterization, modeling and metrology of materials. Further, it addresses currently emerging characterization techniques such as optical and acoustic, vibrational spectroscopy (Brillouin, infrared, Raman), electronic, magnetic, fluorescence correlation imaging, laser lithography, small angle X-ray and neutron scattering and other techniques, including site-selective nanoprobes. The book analyzes the topological aspects to identify and quantify these effects in terms of topology metrics. The topological materials are ubiquitous and range from (i) de novo nanoscale allotropes of carbons in various forms such as nanotubes, nanorings, nanohorns, nanowalls, peapods, graphene, etc. to (ii) metallo-organic frameworks, (iii) helical gold nanotubes, (iv) Möbius conjugated polymers, (v) block co-polymers, (vi) supramolecular assemblies, to (vii) a variety of biological and soft-matter systems, e.g. foams and cellular materials, vesicles of different shapes and genera, biomimetic membranes, and filaments, (viii) topological insulators and topological superconductors, (ix) a variety of Dirac materials including Dirac and Weyl semimetals, as well as (x) knots and network structures. Topological databases and algorithms to model such materials have been also established in this book. In order to understand and properly characterize these important emergent materials, it is necessary to go far beyond the traditional paradigm of microscopic structure-property-function relationships to a paradigm that explicitly incorporates topological aspects from the outset to characterize and/or predict the physical properties and currently untapped functionalities of these advanced materials. Simulation and modeling tools including quantum chemistry, molecular dynamics, 3D visualization and tomography are also indispensable. These concepts have found applications in condensed matter physics, materials science and engineering, physical chemistry and biophysics, and the various topics covered in the book have potential applications in connection with novel synthesis techniques, sensing and catalysis. As such, the book offers a unique resource for graduate students and researchers alike.
Download or read book Quantum Mechanics Volume 3 written by Claude Cohen-Tannoudji and published by John Wiley & Sons. This book was released on 2019-12-16 with total page 790 pages. Available in PDF, EPUB and Kindle. Book excerpt: This new, third volume of Cohen-Tannoudji's groundbreaking textbook covers advanced topics of quantum mechanics such as uncorrelated and correlated identical particles, the quantum theory of the electromagnetic field, absorption, emission and scattering of photons by atoms, and quantum entanglement. Written in a didactically unrivalled manner, the textbook explains the fundamental concepts in seven chapters which are elaborated in accompanying complements that provide more detailed discussions, examples and applications. * Completing the success story: the third and final volume of the quantum mechanics textbook written by 1997 Nobel laureate Claude Cohen-Tannoudji and his colleagues Bernard Diu and Franck Laloë * As easily comprehensible as possible: all steps of the physical background and its mathematical representation are spelled out explicitly * Comprehensive: in addition to the fundamentals themselves, the books comes with a wealth of elaborately explained examples and applications Claude Cohen-Tannoudji was a researcher at the Kastler-Brossel laboratory of the Ecole Normale Supérieure in Paris where he also studied and received his PhD in 1962. In 1973 he became Professor of atomic and molecular physics at the Collège des France. His main research interests were optical pumping, quantum optics and atom-photon interactions. In 1997, Claude Cohen-Tannoudji, together with Steven Chu and William D. Phillips, was awarded the Nobel Prize in Physics for his research on laser cooling and trapping of neutral atoms. Bernard Diu was Professor at the Denis Diderot University (Paris VII). He was engaged in research at the Laboratory of Theoretical Physics and High Energy where his focus was on strong interactions physics and statistical mechanics. Franck Laloë was a researcher at the Kastler-Brossel laboratory of the Ecole Normale Supérieure in Paris. His first assignment was with the University of Paris VI before he was appointed to the CNRS, the French National Research Center. His research was focused on optical pumping, statistical mechanics of quantum gases, musical acoustics and the foundations of quantum mechanics.
Download or read book Coherent Optical Fiber Communications written by T. Okoshi and published by Springer Science & Business Media. This book was released on 1988-07-31 with total page 302 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Single Frequency Fiber Lasers written by Zhongmin Yang and published by Springer. This book was released on 2019-02-19 with total page 174 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book gives a contemporary overview of the technologies of single-frequency fiber lasers. The development of single-frequency fiber lasers is one of the most significant achievements in the field of laser photonics over the past two decades. Owing to the crucial demands of a laser sources with highly stable single-frequency operation, narrow linewidth, low noise, scalable to high output power, compact and robustness structure, fiber lasers have been intensively studied since its introduction to the single-frequency laser community and they still continuously proceed to trigger the emergence of new technologies and applications. This book systematically demonstrates the single-frequency fiber laser technologies from fundamental principles to state-of-the-art progress. Details of selected typical applications of single-frequency fiber lasers are also given and discussed. The reader will acquire a good knowledge of the current situation within this important field.
Download or read book Arbeitstagung Bonn 1984 written by Friedrich Hirzebruch and published by Springer. This book was released on 1985 with total page 514 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Magnetohydrodynamics written by Sergei S. Molokov and published by Springer Science & Business Media. This book was released on 2007-08-26 with total page 408 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book revises the evolution of ideas in various branches of magnetohydrodynamics (astrophysics, earth and solar dynamos, pinch, MHD turbulence and liquid metals) and reviews current trends and challenges. Uniquely, it contains the review articles on the development of the subject by pioneers in the field as well as leading experts, not just in one, but in various branches of magnetohydrodynamics, such as liquid metals, astrophysics, dynamo and pinch.
Download or read book Nonlinear Dirac Equation Spectral Stability of Solitary Waves written by Nabile Boussaïd and published by American Mathematical Soc.. This book was released on 2019-11-21 with total page 297 pages. Available in PDF, EPUB and Kindle. Book excerpt: This monograph gives a comprehensive treatment of spectral (linear) stability of weakly relativistic solitary waves in the nonlinear Dirac equation. It turns out that the instability is not an intrinsic property of the Dirac equation that is only resolved in the framework of the second quantization with the Dirac sea hypothesis. Whereas general results about the Dirac-Maxwell and similar equations are not yet available, we can consider the Dirac equation with scalar self-interaction, the model first introduced in 1938. In this book we show that in particular cases solitary waves in this model may be spectrally stable (no linear instability). This result is the first step towards proving asymptotic stability of solitary waves. The book presents the necessary overview of the functional analysis, spectral theory, and the existence and linear stability of solitary waves of the nonlinear Schrödinger equation. It also presents the necessary tools such as the limiting absorption principle and the Carleman estimates in the form applicable to the Dirac operator, and proves the general form of the Dirac-Pauli theorem. All of these results are used to prove the spectral stability of weakly relativistic solitary wave solutions of the nonlinear Dirac equation.
Download or read book Laser Dynamics written by Thomas Erneux and published by Cambridge University Press. This book was released on 2010-04-29 with total page 376 pages. Available in PDF, EPUB and Kindle. Book excerpt: Bridging the gap between laser physics and applied mathematics, this book offers a new perspective on laser dynamics. Combining fresh treatments of classic problems with up-to-date research, asymptotic techniques appropriate for nonlinear dynamical systems are shown to offer a powerful alternative to numerical simulations. The combined analytical and experimental description of dynamical instabilities provides a clear derivation of physical formulae and an evaluation of their significance. Starting with the observation of different time scales of an operating laser, the book develops approximation techniques to systematically explore their effects. Laser dynamical regimes are introduced at different levels of complexity, from standard turn-on experiments to stiff, chaotic, spontaneous or driven pulsations. Particular attention is given to quantitative comparisons between experiments and theory. The book broadens the range of analytical tools available to laser physicists and provides applied mathematicians with problems of practical interest, making it invaluable for graduate students and researchers.
Download or read book Blackbody Radiometry written by Victor Sapritsky and published by Springer Nature. This book was released on 2020-10-19 with total page 698 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book, the first of a two-volume set, focuses on the basic physical principles of blackbody radiometry and describes artificial sources of blackbody radiation, widely used as sources of optical radiation, whose energy characteristics can be calculated on the base of fundamental physical laws. Following a review of radiometric quantities, radiation laws, and radiative heat transfer, it introduces the basic principles of blackbody radiators design, details of their practical implementation, and methods of measuring their defining characteristics, as well as metrological aspects of blackbody-based measurements. Chapters are dedicated to the effective emissivity concept, methods of increasing effective emissivities, their measurement and modeling using the Monte Carlo method, techniques of blackbody radiators heating, cooling, isothermalization, and measuring their temperature. An extensive and comprehensive reference source, this book is of considerable value to students, researchers, and engineers involved in any aspect of blackbody radiometry.
Download or read book Experimental Chaos written by Stefano Boccaletti and published by A I P Press. This book was released on 2004-12-14 with total page 384 pages. Available in PDF, EPUB and Kindle. Book excerpt: The 8th Experimental Chaos Conference again demonstrated the broad spectrum of areas where nonlinear dynamics plays an important role, such as circuits, hydrodynamics, optics, chemistry, fracture dynamics, neuroscience, and cognitive science. Additional contributions outline the trends for development and application of concepts and techniques of nonlinear dynamics.
