Download or read book Etude de cavit s optiques form es de miroirs de Bragg r seaux pas variable written by Xunqi Wu and published by . This book was released on 2012 with total page 142 pages. Available in PDF, EPUB and Kindle. Book excerpt: L'objectif de cette thèse vise à l'étude d'un laser à cavité étendue et/ou filtre optique, dont le miroir externe est un réseau de Bragg à pas variable linéairement. En ce qui concerne le milieu à gain dans le résonateur, l’amplificateur optique à semiconducteur (SOA, Semiconductor Optical Amplifier) peut offrir toutes les caractéristiques et avantages classiques et typiques tels que large bande passante spectrale de 50 nm, faible consommation, haute rapidité de commutation électro-optique etc.... Par conséquent, ce type de laser et/ou filtre optique offre de nombreuses applications intéressantes dans le domaine des télécommunications optiques.Dans cette recherche, les premiers travaux sont la conception de la cavité continuum passive à l'aide d’un réseau de Bragg à pas variable. A l’intérieur de cette cavité continuum, formée entre un miroir et un réseau de Bragg chirpé, toutes les longueurs d'onde de Bragg oscillent simultanément ; la phase après un aller-retour de chaque longueur d'onde doit rester constante. La largeur de bande passante du spectre de transmission peut être ajustée dans la bande C (entre 1525 nm et 1565 nm) pour répondre aux besoins des systèmes de multiplexage en longueur d'onde (WDM, Wavelength-Division Multiplexing). On appliquera dans un premier temps ce concept de cavité continuum à la conception et la réalisation d’un filtre optique à bande passante variable. Puis dans un deuxième temps on rajoute un amplificateur optique à semi-conducteur (SOA) dans cette cavité pour réaliser un laser dit continuum. On s’attend à une émission sur un large spectre défini par la bande de réflexion du réseau chirpé. Le contrôle et la compréhension des phénomènes liés à cette émission lumineuse feront l’objet de cette étude. La cavité laser dite continuum sera étudiée en régime d’injection optique. L’idée est d’utiliser cette source comme amplificateur résonant fonctionnant en régime d’injection locking. La contribution dans cette thèse couvre à la fois la modélisation numérique, et les manipulations expérimentales. La conception du filtre ainsi que des mesures expérimentales de validation ont été complètement réalisés sur une structure hybride constituée d’une cavité à fibre optique incluant les réseaux de Bragg. Un bon accord entre théorie et expérience a été obtenu. Par contre, les calculs ont montré qu’un filtre optique intégré sur semi-conducteur utilisant ce concept de cavité n’avait pas d’intérêt. Les propriétés spectrales du filtre réalisé montrent en effet qu’on ne pourra obtenir qu’un faible taux de réjection et une qualité médiocre de forme de filtre en version intégrée. La réalisation expérimentale d’une cavité laser continuum a pu être démontrée et les propriétés spectrales enregistrées. En particulier une émission laser avec une largeur de spectre de 10 nm a été observée. Même si il reste un grand travail de caractérisation et de modélisation pour comprendre totalement les mécanismes qui gouvernent le fonctionnement d’une telle structure, c’est un résultat totalement nouveau que l’on a obtenu ici. Cette structure a par ailleurs été testée en régime d’injection optique. Un fonctionnement d’injection locking est obtenu qui permet à cette structure de jouer le role d’amplificateur à faible bruit.

Download or read book Conception de cavit s optiques r sonance largie avec des miroirs de Bragg pas variable written by Grigore-adrian Iordachescu and published by . This book was released on 2013 with total page 126 pages. Available in PDF, EPUB and Kindle. Book excerpt: Cette thèse propose une nouvelle méthode pour générer des spectres continus avec des applications possibles dans les réseaux d'accès optiques WDM. Cette nouvelle méthode devrait permettre le développement d'une structure laser type continuum avec de meilleures performances en termes de coût et de simplicité comparées aux sources supercontinuum actuelles. Dans ce but, nous avons analysé la possibilité d'élargir les modes résonants d'une cavité Fabry-Perot en n'agissant que sur la conception de l'un des miroirs de la cavité. La conception du miroir est réalisée avec un algorithme génétique en ciblant un spectre de réflectivité souhaitée. Un milieu actif est alors ajouté à l'intérieur de la cavité formée avec un tel miroir synthétisé et son comportement en dessous du seuil est simulé. Les spectres des cavités ainsi obtenues sont continus sur une bande de 5 à 15nm.

Download or read book ICREEC 2019 written by Ahmed Belasri and published by Springer Nature. This book was released on 2020-06-10 with total page 659 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book highlights peer reviewed articles from the 1st International Conference on Renewable Energy and Energy Conversion, ICREEC 2019, held at Oran in Algeria. It presents recent advances, brings together researchers and professionals in the area and presents a platform to exchange ideas and establish opportunities for a sustainable future. Topics covered in this proceedings, but not limited to, are photovoltaic systems, bioenergy, laser and plasma technology, fluid and flow for energy, software for energy and impact of energy on the environment.

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 Organic Solid State Lasers written by Sébastien Forget and published by Springer. This book was released on 2013-07-03 with total page 179 pages. Available in PDF, EPUB and Kindle. Book excerpt: Organic lasers are broadly tunable coherent sources, potentially compact, convenient and manufactured at low-costs. Appeared in the mid 60’s as solid-state alternatives for liquid dye lasers, they recently gained a new dimension after the demonstration of organic semiconductor lasers in the 90's. More recently, new perspectives appeared at the nanoscale, with organic polariton and surface plasmon lasers. After a brief reminder to laser physics, a first chapter exposes what makes organic solid-state organic lasers specific. The laser architectures used in organic lasers are then reviewed, with a state-of-the-art review of the performances of devices with regard to output power, threshold, lifetime, beam quality etc. A survey of the recent trends in the field is given, highlighting the latest developments with a special focus on the challenges remaining for achieving direct electrical pumping of organic semiconductor lasers. A last chapter covers the applications of organic solid-state lasers.

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.

Download or read book Laser 50 Years Of Discoveries written by Fabien Bretenaker and published by World Scientific. This book was released on 2014-10-27 with total page 185 pages. Available in PDF, EPUB and Kindle. Book excerpt: This unique book provides an overview of the principle and applications of lasers enriched with numerous illustrations.Being over fifty years old, lasers continue to amaze us. Their performance characteristics are constantly reaching new limits, and the scope of their applications continues to expand. Yet, it took years of effort by teams of physicists to transform the fundamental notions of Einstein into the first experimental beam of laser light. And history is still going on as fundamental research is now triggered by its remarkable properties.This book addresses every aspects of laser light, from its fundamental principles to its industrial applications, at a level particularly suited for high school teachers, students, and anybody curious about science and technology.

Download or read book Lamia Joreige written by Patricia Falguières and published by . This book was released on 2018 with total page 328 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Waves and Vibrations in Soils written by Jean-François Semblat and published by Iuss Press. This book was released on 2009 with total page 510 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Inequalities in Mechanics and Physics written by G. Duvant and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 415 pages. Available in PDF, EPUB and Kindle. Book excerpt: 1. We begin by giving a simple example of a partial differential inequality that occurs in an elementary physics problem. We consider a fluid with pressure u(x, t) at the point x at the instant t that 3 occupies a region Q oflR bounded by a membrane r of negligible thickness that, however, is semi-permeable, i. e., a membrane that permits the fluid to enter Q freely but that prevents all outflow of fluid. One can prove then (cf. the details in Chapter 1, Section 2.2.1) that au (aZu azu aZu) (1) in Q, t>o, -a - du = g du = -a z + -a z + -a z t Xl X X3 z l g a given function, with boundary conditions in the form of inequalities u(X,t»o => au(x,t)/an=O, XEr, (2) u(x,t)=o => au(x,t)/an?:O, XEr, to which is added the initial condition (3) u(x,O)=uo(x). We note that conditions (2) are non linear; they imply that, at each fixed instant t, there exist on r two regions r~ and n where u(x, t) =0 and au (x, t)/an = 0, respectively. These regions are not prescribed; thus we deal with a "free boundary" problem.

Download or read book Mechanics of Generalized Continua written by Gérard A. Maugin and published by Springer Science & Business Media. This book was released on 2010-03-24 with total page 337 pages. Available in PDF, EPUB and Kindle. Book excerpt: In their 1909 publication Théorie des corps déformables, Eugène and François Cosserat made a historic contribution to materials science by establishing the fundamental principles of the mechanics of generalized continua. The chapters collected in this volume showcase the many areas of continuum mechanics that grew out of the foundational work of the Cosserat brothers. The included contributions provide a detailed survey of the most recent theoretical developments in the field of generalized continuum mechanics and can serve as a useful reference for graduate students and researchers in mechanical engineering, materials science, applied physics and applied mathematics.

Download or read book Mathematical Methods for Wave Phenomena written by Norman Bleistein and published by Academic Press. This book was released on 2012-12-02 with total page 360 pages. Available in PDF, EPUB and Kindle. Book excerpt: Computer Science and Applied Mathematics: Mathematical Methods for Wave Phenomena focuses on the methods of applied mathematics, including equations, wave fronts, boundary value problems, and scattering problems. The publication initially ponders on first-order partial differential equations, Dirac delta function, Fourier transforms, asymptotics, and second-order partial differential equations. Discussions focus on prototype second-order equations, asymptotic expansions, asymptotic expansions of Fourier integrals with monotonic phase, method of stationary phase, propagation of wave fronts, and variable index of refraction. The text then examines wave equation in one space dimension, as well as initial boundary value problems, characteristics for the wave equation in one space dimension, and asymptotic solution of the Klein-Gordon equation. The manuscript offers information on wave equation in two and three dimensions and Helmholtz equation and other elliptic equations. Topics include energy integral, domain of dependence, and uniqueness, scattering problems, Green's functions, and problems in unbounded domains and the Sommerfeld radiation condition. The asymptotic techniques for direct scattering problems and the inverse methods for reflector imaging are also elaborated. The text is a dependable reference for computer science experts and mathematicians pursuing studies on the mathematical methods of wave phenomena.

Download or read book Phononic Crystals written by Vincent Laude and published by Walter de Gruyter GmbH & Co KG. This book was released on 2015-09-14 with total page 494 pages. Available in PDF, EPUB and Kindle. Book excerpt: Phononic crystals are artificial periodic structures that can alter efficiently the flow of sound, acoustic waves, or elastic waves. They were introduced about twenty years ago and have gained increasing interest since then, both because of their amazing physical properties and because of their potential applications. The topic of phononic crystals stands as the cross-road of physics (condensed matter physics, wave propagation in inhomogeneous and periodic media) and engineering (acoustics, ultrasonics, mechanical engineering, electrical engineering). Phononic crystals cover a wide range of scales, from meter-size periodic structures for sound in air to nanometer-size structures for information processing or thermal phonon control in integrated circuits. Phononic crystals have a definite relation with the topic of photonic crystals in optics. The marriage of phononic and photonic crystals also provides a promising structural basis for enhanced sound and light interaction. As the topic is getting popular, it is nowadays presented and discussed at various international conferences. After the first ten years during which the topic has remained mainly theoretical with a few proof-of-concept demonstrations in the literature, the evolution has been towards applications, instrumentation, and novel designs. The physical explanations for various effects are now well understood and efficient numerical methods and analysis tools have been developed. The book contains a comprehensive set of finite element model (FEM) scripts for solving basic phononic crystal problems. The scripts are short, easy to read, and efficient, allowing the reader to generate for him(her)self band structures for 2D and 3D phononic crystals, to compute Bloch waves, waveguide and cavity modes, and more.

Download or read book Cambridge Yearbook of European Legal Studies Vol 13 2010 2011 written by Catherine Barnard and published by Bloomsbury Publishing. This book was released on 2011-12-15 with total page 337 pages. Available in PDF, EPUB and Kindle. Book excerpt: The Cambridge Yearbook of European Legal Studies provides a forum for the scrutiny of significant issues in EU Law, the law of the European Convention on Human Rights, and Comparative Law with a 'European' dimension, and particularly those issues which have come to the fore during the year preceding publication. The contributions appearing in the collection are commissioned by the Centre for European Legal Studies (CELS) Cambridge, a research centre in the Law Faculty of the University of Cambridge specialising in European legal issues. The papers presented are at the cutting edge of the fields which they address, and reflect the views of recognised experts drawn from the University world, legal practice, and the institutions of both the EU and its Member States. Inclusion of the comparative dimension brings a fresh perspective to the study of European law, and highlights the effects of globalisation of the law more generally, and the resulting cross fertilisation of norms and ideas that has occurred among previously sovereign and separate legal orders. The Cambridge Yearbook of European Legal Studies is an invaluable resource for those wishing to keep pace with legal developments in the fast moving world of European integration. INDIVIDUAL CHAPTERS Please click on the link below to purchase individual chapters from Volume 13 through Ingenta Connect: www.ingentaconnect.com SUBSCRIPTION TO SERIES To place an annual online subscription or a print standing order through Hart Publishing please click on the link below. Please note that any customers who have a standing order for the printed volumes will now be entitled to free online access. www.hartjournals.co.uk/cyels/subs Editorial Advisory Board: Albertina Albors-Llorens, John Bell, Alan Dashwood, Simon Deakin, David Feldman, Richard Fentiman, Angus Johnston, John Spencer Founding Editors: Alan Dashwood and Angela Ward Ius Commune Prize 2012 Alexandre Saydé wrote Chapter 15 in this volume entitled: 'One Law, Two Competitions: An Enquiry into the Contradictions of Free Movement Law' and we are delighted to announce that he has been awarded the Ius Commune Prize 2012.

Download or read book Socialism Perestroika and the Dilemmas of Soviet Economic Reform written by John E Tedstrom and published by Routledge. This book was released on 2021-12-13 with total page 239 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book highlights that Soviet economic planners and politicians must come to recognize the need to make fundamental changes, not simply incremental refinements, in the failing Soviet system. It examines the dynamics of the process of perestroika and the complexity of individual economic issues.

Download or read book The Ladybird Illustrated written by D H Lawrence and published by . This book was released on 2020-11-09 with total page 100 pages. Available in PDF, EPUB and Kindle. Book excerpt: "The Ladybird is a long tale or novella by D. H. Lawrence. It was first drafted in 1915 as a short story entitled The Thimble. Lawrence rewrote and extended it under a new title in December 1921 and sent the final version to his English agent on 9 January 1922. It was collected with two other tales, The Captain's Doll and The Fox, and the three novellas were then published in London by Martin Secker in March 1923 under the title The Ladybird and in New York by Thomas Seltzer as The Captain's Doll in April 1923."

Download or read book Notes on the Minor Prophets written by Henry Allan Ironside and published by . This book was released on 1955 with total page 464 pages. Available in PDF, EPUB and Kindle. Book excerpt: