Download or read book CONTRIBUTION A L ETUDE D UN RESEAU MULTIMODE DE GUIDES D ONDES COUPLES DANS LA BANDE X written by SERGE.. GUEHO and published by . This book was released on 1982 with total page 238 pages. Available in PDF, EPUB and Kindle. Book excerpt: THEORIE GENERALE DES MODES COUPLES ET THEORIE DES SYSTEMES MULTIPORTES APPLIQUEE AUX GUIDES D'ONDES RECTANGULAIRES ALIMENTES EN MODE TE::(10). PRINCIPE DE FONCTIONNEMENT DES RESEAUX MULTIMODES. POUR CERTAINES VALEURS DU COUPLAGE ENTRE LES GUIDES ON OBTIENT LES DIAGRAMMES DE RAYONNEMENT SOMME ET DIFFERENCE. DETERMINATION DES PARAMETRES DU RESEAU. COMPORTEMENT DU RESEAU EN FONCTION DE LA FREQUENCE

Download or read book Contribution l tude d un r seau multimode de guides d ondes coupl s dans la bande X written by Serge Guého (auteur d'une thèse de sciences.) and published by . This book was released on 1982 with total page 228 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Contribution l tude du coupleur a r seau non lin aire written by Jean-François Roux and published by . This book was released on 1995 with total page 160 pages. Available in PDF, EPUB and Kindle. Book excerpt: CE TRAVAIL PORTE SUR LE DOUBLEMENT DE FREQUENCES OPTIQUES DANS DES GUIDES D'ONDES DEPOSES SUR DES RESEAUX DE DIFFRACTION. LE GUIDE PLANAIRE EST CONSTITUE D'UN FILM MINCE DE POLYMERE NON-LINEAIRE ET LE RESEAU DE DIFFRACTION PERMET SIMULTANEMENT LE COUPLAGE DU FAISCEAU LASER DE POMPE DANS LE GUIDE ET LE DECOUPLAGE DU RAYONNEMENT GENERE A LA FREQUENCE DOUBLE. NOUS RAPPELONS TOUT D'ABORD LES PRINCIPES DE L'OPTIQUE NON-LINEAIRE DANS DES STRUCTURES GUIDANTES AINSI QUE LES NOTIONS FONDAMENTALES DE LA DIFFRACTION LINEAIRE PAR UN RESEAU DE COUPLAGE. ENSUITE, LES PHENOMENES DE DIFFRACTION NON LINEAIRES SONT MODELISES A L'AIDE DE DEUX METHODES. LA PREMIERE EST BASEE SUR LE FORMALISME DES MODES COUPLES, ELLE NOUS PERMET DE RECENSER LES DIFFERENTES POSSIBILITES DE RENFORCEMENT DE LA GENERATION DE SECOND HARMONIQUE, PARMI LESQUELLES L'ACCORD DE PHASE ASSISTE PAR LE RESEAU DE DIFFRACTION. LA SECONDE EST UNE APPROCHE PHENOMENOLOGIQUE QUI PERMET DE MIEUX COMPRENDRE L'INFLUENCE DES PARAMETRES OPTOGEOMETRIQUES DU DISPOSITIF SUR LE PROCESSUS DE DOUBLEMENT DE FREQUENCE. EN UTILISANT DES DISPOSITIFS A INTERFACE METALLIQUE, NOUS RETROUVONS EXPERIMENTALEMENT LES PREVISIONS THEORIQUES. NOTAMMENT, NOUS AVONS MIS EN EVIDENCE L'EFFET DE L'ACCORD DE PHASE OBTENU PAR DISPERSION MODALE EN PRESENCE DE PERTES DE PROPAGATION, AINSI QUE L'INFLUENCE DES HARMONIQUES SPATIAUX DES MODES GUIDES SUR LE RENFORCEMENT DU CHAMP GENERE. A L'AIDE D'UN DISPOSITIF ENTIEREMENT DIELECTRIQUE, NOUS AVONS OBSERVE, POUR LA PREMIERE FOIS, UN ACCORD DE PHASE ASSISTE PAR LE RESEAU ENTRE DEUX MODES GUIDES FONDAMENTAUX SE PROPAGEANT DANS DES DIRECTIONS OPPOSEES

Download or read book Contribution l tude de guides la limite de diffraction coupl s written by Alin Marian Apetrei and published by . This book was released on 2007 with total page 183 pages. Available in PDF, EPUB and Kindle. Book excerpt: La thématique de ce travail sont les guides d'onde à la limite de diffraction à fort contrast d'indice entre le cœur et la gaine, afin de réduire la taille du cœur (qq. μm) tout en gardant le confinement du mode, jusqu'à la limite fondamentale où les effets nonlinéaires (NL) sont maximisés.Déjà proposées en pratique, les fibres microstructurées (MOF) étirées et les barreaux de silice sont courts (~ cm), cassants, difficiles à fabriquer et à manipuler et n'ont pas la possibilité de faire un réseau (essentiel pour les futures circuits de la nano-photonique intégrée).Nous avons proposé d'utiliser les canaux trifoliés de la gaine d'une MOF, où chaque ensemble de trois trous d'air adjacents forme un possible guide d'onde. En utilisant la microscopie optique en champ proche, nous avons démontré que ces canaux sont des guides d'onde à une longueur d'onde adéquate (λ=0,67μm), ayant des pertes à l'état de l'art.Après une étape intermédiaire où nous avons étudié le couplage par onde évanescente dans une MOF asymétrique à deux cœurs, nous avons conçu une fibre MOF multi-cœur de canaux trifoliés identiques, guidant à 1,55 μm.Nous avons démontré le guidage dans tous les canaux, avec des pertes à l'état de l'art ( 0,01 dB/mm/canal). Puis, nous avons démontré que les guides sont couplés entre eux, par l'obtention des cartes de sortie étendues sur toute la structure, après des injections ponctuelles. Puis, en calculant et comparant les écarts types des images de sortie CCD et de cartographie d'injection 2D, avec ceux des cartes des supermodes théoriques et de simulation de propagation, nous avons prouvé la forte efficacité du couplage entre tous les guides du réseau.

Download or read book Contribution l tude des permittivit s dans les bandes des 10 GHz et des 33 GHz Guide d ondes partiellement rempli written by Jérôme de La Noë and published by . This book was released on 1966 with total page 212 pages. Available in PDF, EPUB and Kindle. Book excerpt:

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 Microwave Scanning Antennas Apertures written by Robert C. Hansen and published by . This book was released on 1964 with total page 472 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book AGARD Conference Proceedings written by North Atlantic Treaty Organization. Advisory Group for Aerospace Research and Development and published by . This book was released on 1994 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Wideband Multiband and Smart Antenna Systems written by Mohammad Abdul Matin and published by Springer Nature. This book was released on 2021-09-21 with total page 448 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book provides current R&D trends and novel approaches in design and analysis of broadband, multiband, and smart antennas for 5G and B5G mobile and wireless applications, as well as the identification of integration techniques of these antennas in a diverse range of devices. The book presents theoretical and experimental approaches to help the reader in understanding the unique design issues and more advanced research. Moreover, the book includes chapters on the fundamentals of antenna theory. The book is pertinent to professionals and researchers working in the field of antenna engineering; it is written for graduate students, researchers, academics, and industry practitioners who want to improve their understanding in the current research trends in design analysis of broadband, multiband, and smart antennas for wireless applications.

Download or read book Space Systems as Contributors to the NATO Defence Mission written by North Atlantic Treaty Organization. Advisory Group for Aerospace Research and Development. Mission Systems Panel. Symposium and published by . This book was released on 1997 with total page 202 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book General Relativity and Gravitational Waves written by Joseph Weber and published by Courier Corporation. This book was released on 2004-01-01 with total page 210 pages. Available in PDF, EPUB and Kindle. Book excerpt: An internationally famous physicist and electrical engineer, the author of this text was a pioneer in the investigation of gravitational waves. Joseph Weber's General Relativity and Gravitational Waves offers a classic treatment of the subject. Appropriate for upper-level undergraduates and graduate students, this text remains ever relevant. Brief but thorough in its introduction to the foundations of general relativity, it also examines the elements of Riemannian geometry and tensor calculus applicable to this field. Approximately a quarter of the contents explores theoretical and experimental aspects of gravitational radiation. The final chapter focuses on selected topics related to general relativity, including the equations of motion, unified field theories, Friedman's solution of the cosmological problem, and the Hamiltonian formulation of general relativity. Exercises. Index.

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 Single Photon Manipulation written by Keyu Xia and published by BoD – Books on Demand. This book was released on 2020-11-11 with total page 112 pages. Available in PDF, EPUB and Kindle. Book excerpt: This short book aims to present basic information about single photons in a quick read but with not many details. For this purpose, it only introduces the basic concept of single photons, the most important method of generating single photons in experiments, and a specific emerging field.

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 MILCOM 2005 written by Institute of Electrical and Electronics Engineers and published by . This book was released on 2005 with total page 674 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Quantum Communications and Cryptography written by Alexander V. Sergienko and published by CRC Press. This book was released on 2018-10-03 with total page 248 pages. Available in PDF, EPUB and Kindle. Book excerpt: All current methods of secure communication such as public-key cryptography can eventually be broken by faster computing. At the interface of physics and computer science lies a powerful solution for secure communications: quantum cryptography. Because eavesdropping changes the physical nature of the information, users in a quantum exchange can easily detect eavesdroppers. This allows for totally secure random key distribution, a central requirement for use of the one-time pad. Since the one-time pad is theoretically proven to be undecipherable, quantum cryptography is the key to perfect secrecy. Quantum Communications and Cryptography is the first comprehensive review of the past, present, and potential developments in this dynamic field. Leading expert contributors from around the world discuss the scientific foundations, experimental and theoretical developments, and cutting-edge technical and engineering advances in quantum communications and cryptography. The book describes the engineering principles and practical implementations in a real-world metropolitan network as well as physical principles and experimental results of such technologies as entanglement swapping and quantum teleportation. It also offers the first detailed treatment of quantum information processing with continuous variables. Technologies include both free-space and fiber-based communications systems along with the necessary protocols and information processing approaches. Bridging the gap between physics and engineering, Quantum Communications and Cryptography supplies a springboard for further developments and breakthroughs in this rapidly growing area.

Download or read book Ultra Wide Band Antennas written by Xavier Begaud and published by John Wiley & Sons. This book was released on 2013-03-04 with total page 217 pages. Available in PDF, EPUB and Kindle. Book excerpt: Ultra Wide Band Technology (UWB) has reached a level of maturity that allows us to offer wireless links with either high or low data rates. These wireless links are frequently associated with a location capability for which ultimate accuracy varies with the inverse of the frequency bandwidth. Using time or frequency domain waveforms, they are currently the subject of international standards facilitating their commercial implementation. Drawing up a complete state of the art, Ultra Wide Band Antennas is aimed at students, engineers and researchers and presents a summary of internationally recognized studies.