BENABDESSELAM , Mourad

We have demonstrated by spectral analysis of thermally stimulated luminescence that depending on the quality of the substrate-tube used during the MCVD technique, Yb-doping of silica preforms might be responsible for both the formation of the non-bridging hole centres (NBOHC) and their amount within the final preform. If these centres as well...

Si la dégradation des fibres optiques augmente évidemment avec la dose de rayonnement absorbée, il apparaît tout aussi primordial d'envisager sa dépendance au débit de dose. Cette question est notamment cruciale pour les applications spatiales, dont les conditions d'irradiation, se caractérisant par de très faibles débits et une durée...

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Photodarkening mechanisms of ytterbium-doped silica optical fibers are still not elucidated though hardening routes have been proposed. Most basic questions are still under debate about the assignment of the darkening excitation bands into the UV range, the nature of absorbing centers (photoionized centers or trapped carriers?), or of traps...

The radiation-induced attenuation in silica optical fibers is usually attributed to the formation of color centers. The RIA spectrum is then considered a composition of several characteristic optical absorption bands. We argue, based on experimental and theoretical facts, that the photoionization of radiation-induced bandgap states may also...

This study analyses the thermally stimulated luminescence or thermoluminescence (TL) glow curve between 300 and 773 K of germanium-doped silica optical fibre. A main glow peak at 530 K with a characteristic spectral emission centred at 400 nm is found. Both features are particularly suitable for dosimetry. Thus, an investigation by the TL...

This study analyses the thermally stimulated luminescence or thermoluminescence (TL) glow curve between 300 and 773 K of germanium-doped silica optical fibre. A main glow peak at 530 K with a characteristic spectral emission centred at 400 nm is found. Both features are particularly suitable for dosimetry. Thus, an investigation by the TL...

Global warming is primarily caused by greenhouse gases such as CO2. One smart solution to mitigate its impact is to convert CO2 into hydrocarbons through photoreduction processes. In this work, CO2 was photo-catalytically reduced over new aerogel-based materials to produce methanol, using a solar simulator and a specifically designed...

Erbium-and ytterbium-doped silica-based fibers (EDF and YDF respectively) amplifiers are a reliable technology to achieve high-power fiber laser sources operating around 1 and 1.5 microns. These sources are of primary interest for a variety of industrial and medical applications. Their reduced weight, cost, size and power consumption also make...

Sur la base de caractérisations expérimentales spécifiques, nous proposons un modèle physique validé de la dégradation radio-induite locale dans les fibres optiques dopées terres-rares (erbium et ytterbium principalement) en conditions d'amplification. Ce modèle peut être implémenté naturellement dans les systèmes d'équations aux dérivées...

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Specialty optical fibres experience is a very strong growth in the variety of their application fields, both as passive or active components in optical devices. These components offer ever more original functions, and ever better technical and/or performances efficiency. It is also frequently necessary to integrate several of these functions in...

Radiation effects in ytterbium-doped silica optical fibers are still poorly studied despite their importance in space-based applications as optical inter-satellite links. We investigate such effects by coupling thermally stimulated luminescence and optical absorption measurements. Connections between traps populated by X ray irradiations and...

Radiation effects in ytterbium-doped silica optical fibers are still poorly studied despite their importance in space-based applications as optical inter-satellite links. We investigate such effects by coupling thermally stimulated luminescence and optical absorption measurements. Connections between traps populated by X ray irradiations and...

By considering samples of ytterbium-doped silica glass from fibre preforms, we will show how TSL allows direct comparison between colour centres created by X-ray, UV light (at several wavelengths) and by the visible radiation of an Ar+ ion laser. This comparison will lead us to propose plausible darkening mechanisms with related models.

L'industrie spatiale est toujours en demande de technologies susceptibles d'améliorer les performances de ses systèmes en termes de masse, de consommation et de volume. L'utilisation de fibres optiques permet une réduction significative de la taille et de la masse des systèmes de distribution de signaux à bord des satellites. Les liaisons...

We present an original experimental approach to the investigation of radiation-induced attenuation (RIA) mechanisms in optical fiber preforms. This protocol combines thermally stimulated luminescence (TSL) measurements with the characterization of RIA annealing during TSL readouts. It is systematically applied to compositions of increasing...

Thanks to its high thermal conductivity, aluminum nitride may be a serious candidate as fuel coating for the Gas Fast Reactor. However, its behavior under irradiation is not entirely well understood. In order to catch a glimpse of this behavior, specimens were irradiated with swift heavy ions of different energies then characterised by both...

L'analyse croisée de la thermoluminescence résolue spectralement, de l'atténuation radio-induite et du blanchiment thermique d'échantillons de préformes présentant des compositions de complexité croissante (silice, silice dopée aluminium ou ytterbium, alumino-silicate dopée ytterbium, alumino-silicate co-dopée ytterbium et cérium) permet de...

La tenue des amplificateurs à fibres en silice dopées ytterbium (FDY) opérés en environnement sévère pose la question de l'interaction entre le photo-noircissement (PN) et le radio-noircissement (RN), c'est à dire de la dégradation subie lorsque l'amplificateur est soumis à l'action simultanée de la pompe et de l'irradiation ionisante. Bien...