Nanoparticle Doping of Optical Fibers – Can Silica Behave like a Fluoride?

International audienc

Vie et mort d'une nanoparticule de LaF3 dans la silice à haute température

National audienc

Thulium-doped nanoparticles and their properties in silica-based optical fibers

International audienceLasers and amplifiers based on thulium-doped silica fibers require improved spectroscopic properties. In this context, one of the most promising approaches is based on the embedding of thulium ions in nanoparticles of tailored composition and structure. This paper presents various methods used to produce thulium-doped nanoparticles inside silica-based optical fibers. Effects of solution doping method during the elaboration of Modified Chemical Vapor Deposition preform and doping solution composition are studied. A comparison is made between the use of solutions containing LaF3:Tm3+ or YAG:Tm3+ nanoparticles and aluminum-lanthanum-thulium chlorides. Results show that for similar lanthanum content, lanthanum-thulium chlorides doping allows for similar enhancement of H-3(4) level of Tm3+ than LaF3:Tm3+ doping. Also, effects of aluminum on H-3(4) lifetime enhancement and inhibition of nanoparticle's formation is discussed

Stability of Grafted Polymer Nanoscale Films toward Gamma Irradiation

The present article focuses on the influence of gamma irradiation on nanoscale polymer grafted films and explores avenues for improvements in their stability toward the ionizing radiation. In terms of applications, we concentrate on enrichment polymer layers (EPLs), which are polymer thin films employed in sensor devices for the detection of chemical and biological substances. Specifically, we have studied the influence of gamma irradiation on nanoscale poly­(glycidyl methacrylate) (PGMA) grafted EPL films. First, it was determined that a significant level of cross-linking was caused by irradiation in pure PGMA films. The cross-linking is accompanied by the formation of conjugated ester, carbon double bonds, hydroxyl groups, ketone carbonyls, and the elimination of epoxy groups as determined by FTIR. Polystyrene, 4-amino-2,2,6,6-tetramethylpiperidine-1-oxyl, dimethylphenylsilanol, BaF₂, and gold nanoparticles were incorporated into the films and were found to mitigate different aspects of the radiation damage