Download or read book Saturation spectrale de gain dans les amplificateurs fibres dop es erbium written by Romain Peretti and published by . This book was released on 2008 with total page 175 pages. Available in PDF, EPUB and Kindle. Book excerpt: L’augmentation exponentiel des performances des lignes de télécommunication optique est en partie du au développement de deux technologie : l’amplificateur à fibre dopée erbium(EDFA) et l’utilisation du multiplexage en longueur d’onde (WDM). Or, combinée, ces des technologies font apparaitre sur les lignes de télécommunication le problème de saturation spectrale du gain (GSHB), un trou se perce dans la bande de gain lorsqu’un fort signal passe dans la fibre amplificatrice. Ce travail de thèse étudie donc ce problème afin de le relier à des grandeurs et des phénomènes physiques connus. Nous avons donc du procédé à des expériences de spectrométrie directement sur fibre optique afin d’effectuer des comparaisons entre les grandeurs mesurée sur échantillons massifs, et en particulier la largeur homogène, celle mesurée sur fibre optique à la fois par des technique comparables (RFLN), et via le trou de GSHB. Nous avons ensuite effectué la première modélisation de l’EDFA qui tient compte des aspects inhomogènes de la répartition de l’erbium dans la matrice hôte, celui-ci rend pour la première fois, compte qualitativement de phénomène lié à l’inhomogénéité tel que le GSHB. Enfin nous avons étudié de nouveaux matériaux utilisables pour l’amplification optique fibré, des matériaux nanostructurés. En effet, contrôler l’environnement de l’erbium indépendamment de la matrice hôte, permettrait d’optimiser à la fois les propriétés de luminescence de l’erbium et les aspects fibrage et guide optique de l’EDFA. Nous avons donc mis en évidence les propriétés particulières de l’erbium dans ces nanoparticules
Download or read book Gain Saturation Behavior and Spectral hope Burning Effect in Erbium doped Fiber Amplifiers written by and published by . This book was released on 2001 with total page 49 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Etude des effets de polarisation et de saturation dans les amplificateurs optiques fibre dop e erbium written by FREDERIQUE.. DUPRE and published by . This book was released on 1997 with total page 161 pages. Available in PDF, EPUB and Kindle. Book excerpt: L'OBJECTIF DE CETTE THESE EST D'ETUDIER LES EFFETS DE POLARISATION ET DE SATURATION DANS LES AMPLIFICATEURS A FIBRE DOPEE ERBIUM (AFDE). APRES UNE PRESENTATION GENERALE DE L'AFDE, NOUS INTRODUISONS LA NOTION D'ETATS DE POLARISATION AINSI QUE LES DIFFERENTS OUTILS MATHEMATIQUES PERMETTANT DE REPRESENTER LA POLARISATION DE LA LUMIERE. DANS LA SECONDE PARTIE DE CE TRAVAIL, NOUS ETUDIONS LES PHENOMENES QUI MODIFIENT L'ETAT DE POLARISATION DU SIGNAL : LA BIREFRINGENCE ET LA DISPERSION MODALE DE POLARISATION (PMD). APRES UNE COMPARAISON DES DIFFERENTES TECHNIQUES DE MESURE DE PMD, NOUS PRESENTONS UN ENSEMBLE DE RESULTATS DE MESURE SUR DES AMPLIFICATEURS ET SUR LES COMPOSANTS QUI LES CONSTITUENT. NOUS MONTRONS QUE LES ISOLATEURS SONT RESPONSABLES D'UNE PART IMPORTANTE DE LA PMD DES AMPLIFICATEURS. DANS LA DERNIERE PARTIE, NOUS AVONS REGROUPE LES DEUX EFFETS LIES A LA SATURATION ET AFFECTANT LE GAIN D'UN AMPLIFICATEUR : D'UN COTE LES EFFET DUS A LA POLARISATION ET DE L'AUTRE LES EFFETS DUS A LA LONGUEUR D'ONDE. ILS SONT MIS EN EVIDENCE SUR LE MEME BANC DE MESURE PERMETTANT DE FAIRE VARIER SOIT LA POLARISATION DE LA LUMIERE, SOIT SA LONGUEUR D'ONDE. L'ETUDE DE LA SATURATION SPECTRALEMENT SELECTIVE DU GAIN NOUS A PERMIS D'EVALUER L'ERREUR FAITE SUR LA DETERMINATION DU GAIN LORSQU'UNE SEULE SOURCE REMPLACE UN PEIGNE DE LONGUEURS D'ONDE.
Download or read book Cathodoluminescence in Geosciences written by M. Pagel and published by Springer Science & Business Media. This book was released on 2013-06-29 with total page 518 pages. Available in PDF, EPUB and Kindle. Book excerpt: An up-to-date overview of cathodoluminescence microscopy and spectroscopy in the field of geosciences, including new important data on cathodoluminescence spectroscopy, physical parameters and systematic spectral analysis of doped minerals. Each chapter, written by a well-known specialist, covers classic and new fields of application such as carbonate diagenesis, silicates, brittle deformation in sandstones, gemstone recognition, biomineralization, economic geology or geochronology. Useful to all scientists, graduates and professional engineers throughout the geosciences community.
Download or read book Masters Theses in the Pure and Applied Sciences written by Wade H. Shafer and published by Springer. This book was released on 1976 with total page 320 pages. Available in PDF, EPUB and Kindle. Book excerpt: Masters Theses in the Pure and Applied Sciences was first conceived, published, and dis· seminated by the Center for Information and Numerical Data Analysis and Synthesis (CINDAS) *at Purdue University in 1957, starting its coverage of theses with the academic year 1955. Beginning with Volume 13, the printing and dissemination phases of the ac· tivity were transferred to University Microfilms/Xerox of Ann Arbor, Michigan, with the thought that such an arrangement would be more beneficial to the academic and general scientific and technical community. After five years of this joint undertaking we had concluded that it was in the interest of all concerned if the printing and distribution of the volume were handled by an international publishing house to assure improved service and broader dissemination. Hence, starting with Volume 18, Masters Theses in the Pure and Applied Sciences has been disseminated on a worldwide basis by Plenum Publishing Corporation of New York, and in the same year the coverage was broadened to include Canadian universities. All back issues can also be ordered from Plenum. We have reported in Volume 20 (thesis year 1975) a total of 10,374 theses titles from 28 Canadian and 239 United States universities. We are sure that this broader base for theses titles reported will greatly enhance the value of this important annual reference work. The organization of Volume 20 is identical to that of past years. It consists of theses titles arranged by discipline and by university within each discipline.
Download or read book Greenhouse Technology written by G. N. Tiwari and published by . This book was released on 1998 with total page 503 pages. Available in PDF, EPUB and Kindle. Book excerpt: Greenhouses are framed or inflated structures, covered with transparent or translucent material in which crops are grown. Greenhouse cultivation and other models of environment cultivation have been evolved to create favourable micro-climates under which crop production is made possible. Greenhouse food production provides forward movement with a greater degree of environment control. It presents the ultimate in intensive agriculture considering three major factors: land; labour; and capital.
Download or read book Human Population Cytogenetics written by and published by . This book was released on 1970 with total page 325 pages. Available in PDF, EPUB and Kindle. Book excerpt:
