78 research outputs found
Structure de verres de silicophosphate dopés europium : analyse par spectroscopie optique et simulation de dynamique moléculaire
National audienc
Europium site symmetry in sol gel silicophosphate glass : FLN spectroscopy and Molecular Dynamics simulation
International audienc
Effects of the preform-to-fiber drawing on the nanoscale structure of a pure silica glass: a molecular dynamics study
Un potentiel adaptatif simple pour la modélisation par Dynamique Moléculaire de la séparation de phase dans un verre de silice binaire
National audienc
Characterization of Erbium-Doped Nanoparticles in Transparent Glass Ceramic Optical Fibres
We report on using nanometric mass spectroscopy and molecular dynamics modelling to characterize the composition and structure of self-grown erbium-doped nanoparticles in transparent glass ceramic optical fibres fabricated by modified chemical vapour deposition without post-ceramming
Molecular dynamics simulation and crystal field calculations of the Eu2O3-PbO-SiO2 glassy system submitted to long annealing time
The Eu2O3-PbO-SiO2 glassy system submitted to a long annealing time (100 ps) has been obtained by molecular dynamics calculations. The average of 87/86 sites of the Eu3 + ion with six/seven nearest neighbours are used to discuss the number of lines and the local symmetry of the luminescent site through the crystal field parameters, using the simple overlap model in the frame of the method of equivalent nearest neighbours. The magnitude of the [View the MathML source] Bq2(q = 0, 1, 2) and the non-negligible [View the MathML source] B44 and [View the MathML source] B46( [View the MathML source] B34, [View the MathML source] B36 and [View the MathML source] B66) lead to the indication of distorted C4h and C3i site symmetries of the six and seven nearest neighbours, respectively. We have then compared very satisfactorily our 7F1 sublevels calculations with those observed in the emission spectra of an Eu-borate glass annealed for 30 min and 17 h. This comparison is justified because the emission behaviour of europium ions in different glassy systems are honestly very similar. Further, the decrease observed in the 5D0→7F2/5D0→7F1 transition intensity ratio is a clear indication that the Eu3 + ion are nucleating a crystalline phase. Such satisfactory comparisons indicate that we have obtained a transparent glass-ceramics
Simulation par dynamique moléculaire de la structure des verres dopés terre rare
National audienc
Erbium-doped transparent glass ceramic optical fibres: Characterization using mass spectroscopy and molecular dynamics modeling
Rare earth (RE) doped silica-based optical fibres with transparent glass ceramic (TGC) core were fabricated through the well-known modified chemical vapor deposition (MCVD) process without going through the commonly used stage of post-ceramming. The main characteristics of the RE-doped
dielectric nanoparticles (DNP), their density and mean diameter in thefibres are dictated by various parameters. This paper reports on progresses in the fine characterization of the nanopaticles, particularly their dimensions and composition, using nanosclae mass spectroscpy and molecular dynamics modeling, and alteration of the spectroscopic properties of the erbium ions embedded within the phospho-silicate DNP. These results permit to get more insight into the complex process of the
DNP self-nucleation and growth during the fibre fabrication process. This fabrication route could have important potentials in improving rare-earth-doped fibre amplifiers and laser sources
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