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Accueil du site > Séminaires > Archives > Année 2013 > Exposés de 2e année de thèse

Exposés de 2e année de thèse

Mercredi 9 octobre 2013

à 10h en salle C. Brot

10:00 - Bin-Ngah Lutfi-Arif

All-Optical Synchronization for Quantum Communication Networks

(dir : Anders Kastberg et Sébastien Tanzilli )

The goal of my PhD is to demonstrate an original protocol of an all-optical synchronization scheme for quantum relay configuration based on the distribution of an ultrafast optical clock. During the fisrt year, I performed investigations on the so-called Hong-Ou-Mandel (HOM) dip phenomena which serves as a necessary tool to validate the photon pair source synchronization at the heart of my project. For the moment, by taking advantage of the current mounted setup and cutting-edge available telecom devices such as GHz laser, low-loss Dense Wavelength Division Multiplexor (DWDM) and ultrafast Superconducting Single Photon Detector (SSPD), we aim at demonstrating the fastest heralded single photon source ever reported in the quantum communication community. Promising preliminary results have been achieved and ever since then, we have been pursuing our efforts for optimizing every single piece of the system so as to yield better results. For this presentation, it is my intention to share with you, some of our best results, our approaches in realizing those quantum experiments, and finally the perspectives for my 3rd year doctoral study.

10:30 - Mebrouk Yasmine

Exploration des voies de durcissement et de tests accélérés des sources laser fibrées de forte puissance destinées aux applications spatiales

(dir : Mourad Benabdesselam et Franck Mady)

L’intégration des fibres optiques amplificatrices (FOAs) dans les technologies aérospatiales embarquées se heurte à la dégradation des performances des FOAs sous l’effet des radiations spatiales . Notre objectif est de développer une procédure de « qualification spatiale », consistant à vérifier sur Terre que la fibre franchit un test standardisé de tenue au rayonnement.

11:00 - Moncel Matthieu

A comparison of advanced DSC techniques for the study of complex thermal effects

(Dir : Nicolas Sbirrazzuoli)

Relevant information can be obtained using thermoanalytical techniques in the characterization of complex natural products. Differential Scanning Calorimetry (DSC) is a powerful tool for thermal characterization of many complex materials such as honeys, paraffin waxes, beeswaxes, biopolymers, gels, polymers blend or vitrification during cure [i,ii,iii,iv,v,vi,vii]. Nevertheless, these materials often present a superposition of various complex convoluted thermal effects, such as glass transition, enthalpy relaxation, cold crystallization, melting, solidification, evaporation and dissolution. In many cases, the corresponding thermal effects are small and overlap each other, that leads to difficult interpretation. The complex behavior is generally due to the superimposition of phase transformation and time dependent phenomena. In these cases, advanced DSC techniques such as Temperature Modulated Differential Scanning Calorimetry (TMDSC/ADSC) or stochastically modulated DSC (TOPEM®) can be efficient techniques. In the present study, diethanolamine (DEA) and triethanolamine (TEA) will be used as model molecules to compare the potential of regular Differential Scanning Calorimetry (DSC), TMDSC and TOPEM® to the interpretation of complex overlapping thermal effects. After a rapid presentation of the thermodynamic concepts herein and of the principle of each techniques, applications to the study of glass transition, enthalpy relaxation, cold crystallization, melting on cooling will be presented. The influence of the thermal history and physical aging will be highlighted. A comparison of the different techniques will be given for baseline determination as well as heat capacity and crystallinity measurements. The advantages and drawbacks of each technique will be presented. Then, the study will show how the various parameters used in these non-trivial techniques should be optimized and must be adapted to the own dynamics of each physical transition under study.

[i] C. Cordella, J. F. Antinelli, C. Aurieres, J. P. Faucon, D. Cabrol-Bass, N. Sbirrazzuoli. J. Agric. Food Chem., 2002, 50(1), 203-208.

[ii] C. Cordella, I. Moussa, A. C. Martel, N. Sbirrazzuoli, L. Lizzani-Cuvelier. J. Agric. Food Chem., 2002, 50(7), 1751-1764.

[iii] C. Cordella, J. P. Faucon, D. Cabrol-Bass, N. Sbirrazzuoli. J. Therm. Anal. Calorim., 2003, 71(1), 279-290.

[iv] S. Vyazovkin, L. Vincent, N. Sbirrazzuoli. Macromol. Biosci., 2007, 7, 1181–1186.

[v] N. Guigo, A. Mija, L. Vincent, N. Sbirrazzuoli. Phys. Chem. Chem. Phys., 2009, 11, 1227-1236.

[vi] Y. Gaillard, A. Mija, A. Burr, E. Darque-Ceretti, E. Felder, N. Sbirrazzuoli. Thermochim. Acta, 2011, 521, 1-2, 90-97.

[vii] I. Fraga, S. Montserrat, J.M. Hutchinson. J. Therm. Anal. Calorim., 2008, 91,687-695.

11:30 - Duchez Jean-Bernard

Les effets simultanés du photo et radio-noircissement sur les fibres optiques aluminosilicates dopées Ytterbium

(dir : Mourad Benabdesselam et Franck Mady)

La communauté traitant des fibres optiques s’intéresse principalement au photo-noircissement, c’est-à-dire à l’action délétère du laser pompant le milieu à gain. Mais il existe aussi un noircissement radio-induit, c’est-à-dire consécutif à l’application d’un rayonnement ionisant (rayons, gamma ...). Mon travail porte sur l’étude simultanée de ces deux phénomènes et la compétition entre la dégradation et la guérison induite par ces deux phénomènes.