Browsing by Author "Kellou, A."

Filter results by typing the first few letters
Now showing 1 - 3 of 3
  • No Thumbnail Available
    Item
    Brillouin Instability In Fiber Lasers Doped By Power
    (University of Eloued جامعة الوادي, 2012-01-01) Bouras, D. M.; Kellou, A.; Leblond, H.; Sanchez, F.
    With the emergence of rare-earth doped fibers, and especially double-clad fibers, there is a renewed interest in Brillouin effect. First of all, the amplification of a continuous signal in a rare-earth doped fiber amplifier can generate high enough intensities to excite Brillouin effect and then to create a backscattered stokes wave. Such back-reflection is detrimental for amplifier applications and consequently it has been studied theoretically and experimentally. Recently, the low frequency self-pulsing instability resulting from Brillouin backscattering has been theoretically modelled [1]. Our main objective is to present a general model allowing to explain the origin of the dynamic instability arising in a fiber lasers as a consequence of Brillouin effect. The effect of Brillouin back scattering is theoretically analysed by two-coupled modes laser model. We consider the Fabry-Perot fiber laser cavity. The rich and complex dynamic behaviours are observed. In particular the quasi periodic dynamic is identified and studied.
  • No Thumbnail Available
    Item
    Study Of The Propagation Of Short Pulse Laser With Cavity Using Numerical Simulation Software
    (University of Eloued جامعة الوادي, 2012-01-01) Terniche, S.; Kellou, A.; Kermaoui, A.; Si Fodil, R.; Becheker, R.
    The purpose of this representation is to show the potentialities (Computational Time, access to the dynamic and feasibility of systematic studies) of the numerical study of the nonlinear dynamics in laser cavity, assisted by software. We will give as an example, one type of cavity completely fibered composed of several elements and then studying the physical parameters of a pulse propagating into this cavity, determining its characteristics at the output. The results are interesting but we also projects to verify them experimentally by making assemblies similar to this type of cavities.
  • No Thumbnail Available
    Item
    SYSTEME LASER SOLAIRE FONCTIONNE EN MONOMODE ET MULTIMODE POMPE PAR DIFFERENTS FORME DE GUIDES DE LUMIERE EN SILICE FONDUE
    (University of Eloued جامعة الوادي, 2018-02-05) Bouadjemine, R.; Liang, D.; Almeida, J.; Louhibi, D.; Kellou, A.
    Notre travail consiste à optimiser les différents paramètres de pompage d’un système laser solaire, en utilisant une technique de calcul numérique dit « Ray-tracing » à l’aide du logiciel ZEMAX. Il a aussi pour objectif d’optimiser les paramètres du résonateur optique afin d’obtenir un rendement laser maximum en régimes multimodes et monomode TEM00, en utilisant le logiciel LASCAD. Ce système laser est constitué d’un système de collection et de concentration des rayonnements solaires grâce à un héliostat-miroir parabolique, d’un guide de lumière en silice fondue, d’une tête laser constituée d’une cavité de pompage de différentes formes assurant un bon couplage des rayonnements solaires vers le barreau laser Nd :YAG, et d’un système de refroidissement