Author: Fabrice Marchese
Publisher:
ISBN:
Category :
Languages : fr
Pages : 0

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Author: FABRICE.. MARCHESE
Publisher:
ISBN:
Category :
Languages : fr
Pages : 145

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Book Description
CETTE ETUDE PORTE SUR LA REPONSE D'UN LASER FABRY-PEROT A SEMI-CONDUCTEUR A L'INJECTION DE PUISSANCE OPTIQUE. NOUS NOUS ATTACHONS A EN MONTRER LES POTENTIALITES ET A FAIRE RESSORTIR CERTAINES APPLICATIONS SUSCEPTIBLES D'ETRE UTILISEES DANS LES TELECOMMUNICATIONS OPTIQUES. L'ETUDE COMMENCE PAR UN RAPPEL DES NOTIONS SUR LES SEMI-CONDUCTEURS NECESSAIRES A UNE MODELISATION DU COMPORTEMENT DE CE COMPOSANT. NOUS EN PRESENTONS ENSUITE UNE CARACTERISATION EXPERIMENTALE COMPAREE AVEC LA THEORIE. LA DEUXIEME PARTIE EST CONSACREE A L'ETUDE DU PHENOMENE DE VERROUILLAGE ABOUTISSANT A UNE CARACTERISTIQUE ENTREE/SORTIE A DEUX ETATS. LE LASER PEUT DONC ETRE UTILISE EN COMPARATEUR DONT UNE DES FONCTIONS POSSIBLES EST LA REGENERATION DE SIGNAUX LUMINEUX INCIDENTS. DE PLUS, NOUS PRESENTONS UN MODELE THEORIQUE PERMETTANT DE CALCULER LES PLAGES DE VERROUILLAGE. EN TROISIEME LIEU NOUS ETUDIONS L'INJECTION DE DEUX FAISCEAUX OPTIQUES DE LONGUEURS D'ONDE DISTINCTES, SITUEES DANS LE SPECTRE DE GAIN DU LASER. LE COMPORTEMENT RESULTANT PERMET DE REALISER DES TRANSPOSITIONS DE LONGUEURS D'ONDE DE SIGNAUX BINAIRES A HAUTS DEBITS. ENFIN NOUS NOUS INTERESSONS AUX PHENOMENES D'INSTABILITE DU VERROUILLAGE DANS LE BUT DE GENERER DES SIGNAUX HYPERFREQUENCE. LES FREQUENCES PRODUITES VARIENT ENTRE 4 ET 8 GHZ.

Author: Jean-Marc Goujon
Publisher:
ISBN:
Category :
Languages : fr
Pages : 159

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Book Description
LES LIAISONS OPTIQUES UTILISANT DES LASERS A SEMI-CONDUCTEURS A FAIBLE COUT REPRESENTENT UNE ALTERNATIVE INTERESSANTE AU CABLE LORSQUE LE POIDS EST UN CRITERE PLUS IMPORTANT QUE LE DEBIT D'INFORMATION. DANS CE CONTEXTE, UNE ETUDE DES CARACTERISTIQUES DES LASERS FABRY-PEROT A DEUX ELECTRODES EST PRESENTEE. UN MODELE MULTIMODE DECRIVANT LE COMPORTEMENT DU LASER EN TERMES DE PUISSANCE ET D'ACCORDABILITE EST PRESENTE. IL MET EN EVIDENCE LA POSSIBILITE D'OBTENIR UN FONCTIONNEMENT MONOMODE PAR LE CHOIX DES COURANTS DE REPOS. DE MEME, IL EST MONTRE THEORIQUEMENT QUE TOUS CES POINTS DE REPOS PROPOSENT DES PERFORMANCES INEGALES EN MODULATION PAR UN SIGNAL DE FAIBLE AMPLITUDE. LA CARACTERISATION DE LASERS FABRY-PEROT BI-ELECTRODES FAIT APPARAITRE DES QUALITES SPECTRALES MEILLEURES QUE CELLES ATTENDUES, EN ACCORDABILITE DISCONTINUE ET EN TAUX DE SUPPRESSION DES MODES LATERAUX. UNE CARTOGRAPHIE DES LASERS EST EFFECTUEE, IL RESSORT DE CETTE ETUDE QUE LA SEPARATION DES ELECTRODES INFLUE SUR LA REPARTITION DE LA PUISSANCE DANS LES DIFFERENTS MODES. LA MODELISATION DE CETTE SEPARATION SOUS FORME D'INTERFACE PARTIELLEMENT REFLECHISSANTE MET EN EVIDENCE UNE NETTE AMELIORATION DE LA QUALITE DU SPECTRE POUR DES FAIBLES REFLEXIONS, DES REFLEXIONS PLUS IMPORTANTES RENDANT LA CARTOGRAPHIE DU LASER ANARCHIQUE. UNE EXPERIENCE DE TRANSPOSITION DE LONGUEUR D'ONDE OPTIQUE EST REALISEE A PARTIR D'UN COMPOSANT A DEUX ELECTRODES COMPORTANT UNE REFLEXION INTERNE.

Author: Jean-Luc Vey
Publisher:
ISBN:
Category :
Languages : fr
Pages : 208

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Author: Jean-Marc Goujon
Publisher:
ISBN:
Category :
Languages : fr
Pages : 0

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Author: Sébastien Forget
Publisher: Springer
ISBN: 3642367054
Category : Science
Languages : en
Pages : 179

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Book Description
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.

Author: Thomas Erneux
Publisher: Cambridge University Press
ISBN: 9780521830409
Category : Science
Languages : en
Pages : 376

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Book Description
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.

Author: Institute of Electrical and Electronics Engineers
Publisher:
ISBN:
Category :
Languages : en
Pages : 674

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Book Description

Author: Fabien Bretenaker
Publisher: World Scientific
ISBN: 9814612421
Category : Science
Languages : en
Pages : 185

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Book Description
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.

Author: Jean-Paul Blaizot
Publisher: Mit Press
ISBN: 9780262022149
Category : Science
Languages : en
Pages : 657

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Book Description
This book provides a comprehensive and pedagogical account of the various methods used in the quantum theory of finite systems, including molecular, atomic, nuclear, and particle phenomena. Covering both background material and advanced topics and including nearly 200 problems, Quantum Theory of Finite Systems has been designed to serve primarily as a text and will also prove useful as a reference in research. The first of the book's four parts introduces the basic mathematical apparatus: second quantization, canonical transformations, Wick theorems and the resulting diagram expansions, and oscillator models. The second part presents mean field approximations and the recently developed path integral methods for the quantization of collective modes. Part three develops perturbation theory in terms of both time-dependent Feynman diagrams and time-independent Goldstone diagrams. A fourth part discusses variational methods based on correlated wavefunctions, including spin correlations. The approximation schemes are formulated for fermions and bosons at eigher zero or non-zero temperature. Although the formalism developed applies to both finite and infinite systems, the book stresses those aspects of the theory that are specific to the description of finite systems. Thus special attention is given to mean field approximations, the ensuing broken symmetries, and the associated collective motions such as rotations. Conversely, some specific features of systems with infinite numbers of degrees of freedom (such as the thermodynamic limit, critical phenomena, and the elimination of ultraviolet divergencies) are deliberately omitted. Jean-Paul Blaizot and Georges Ripka are associated with the Centre d'Etudes Nucleaires de Saclay.