The Experts below are selected from a list of 444 Experts worldwide ranked by ideXlab platform
Xianghua Zhang - One of the best experts on this subject based on the ideXlab platform.
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Sulfide-Halide Glasses with high nonlinear refractive index and low nonlinear absorption
Optical Materials, 2010Co-Authors: Quentin Coulombier, M. Sergent, K. Fedus, G. Boudebs, Johann Troles, G. Canat, O. Vasseur, Pascal Bourdon, M. Cathelinaud, Xianghua ZhangAbstract:Determination of the composition with the best optical and physical properties in a sulfide-Halide arsenic-free vitreous domain, GeS2-Sb2S3-CsI, is described. The characteristic temperatures: glass transition (Tg) and crystallization temperatures (Tx) are measured to determine the difference Tx−Tg. The nonlinear index and absorption, the linear index are measured on nine samples in the vitreous domain. With an experimental device, cartographies of each property are created. The model permits to find a composition with a good compromise for Tx−Tg, nonlinear index and nonlinear absorption. The model emphasizes the influence of each element on each property.
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Research on the correlation between the optical gap and chemical bond in sulphur and selenium co-doped chalco-Halide Glasses.
Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy, 2010Co-Authors: Mingxing Zhu, Qiuhua Nie, Xunsi Wang, Shixun Dai, Xianghua Zhang, Xiang Shen, Guoxiang WangAbstract:The Ge-Ga-Se-S-CsCl Glasses were prepared by the melting-quenching method. The absorption and transmission spectrum were measured under room temperature. It is found that these Glasses have high broad spectral range of transparency from visible to far-infrared region (0.4-12 microm). The relationship between the optical gap and chemical composition in terms of novel chalco-Halide Glasses is discussed based on the Pauling's theory model, which is using the modified heats of atomization and the coordination number of the elements, to explain this phenomena for the first time.
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high tg germanium tellerium Halide Glasses
Journal of Non-crystalline Solids, 1993Co-Authors: P Klaska, Xianghua Zhang, Jacques LucasAbstract:Abstract ChalcoHalide Glasses for infrared transmission have been investigated in the GeTeAsI and GeeAsI systems. The glass-forming region, thermal properties and infrared transmission were studied. Stable Glasses containing up to 15 at.% iodine have a glass temperature ranging from 180 to 250°C and exhibit no peak of crystallization when heated at a rate of 10°C/min. Various purification techniques have been used to remove oxygen impurities. These Glasses are characterized by a broad optical window lying from 2 to 15 μm without any absorption peak due to impurities.
Guoxiang Wang - One of the best experts on this subject based on the ideXlab platform.
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Research on the correlation between the optical gap and chemical bond in sulphur and selenium co-doped chalco-Halide Glasses.
Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy, 2010Co-Authors: Mingxing Zhu, Qiuhua Nie, Xunsi Wang, Shixun Dai, Xianghua Zhang, Xiang Shen, Guoxiang WangAbstract:The Ge-Ga-Se-S-CsCl Glasses were prepared by the melting-quenching method. The absorption and transmission spectrum were measured under room temperature. It is found that these Glasses have high broad spectral range of transparency from visible to far-infrared region (0.4-12 microm). The relationship between the optical gap and chemical composition in terms of novel chalco-Halide Glasses is discussed based on the Pauling's theory model, which is using the modified heats of atomization and the coordination number of the elements, to explain this phenomena for the first time.
Yannick Ledemi - One of the best experts on this subject based on the ideXlab platform.
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transmission enhancement in chalco Halide Glasses for multiband applications
Optical Materials Express, 2014Co-Authors: Yannick Ledemi, Mohammed El Amraoui, Younes MessaddeqAbstract:The potential of clear Ga2S3-GeS2-CsCl based sulfide Glasses transparent up to 11.5 μm to be used as new optical material for multispectral applications has been investigated. The addition of large amount of chlorine ions – above 40 mol.% of CsCl – into the chalcogenide vitreous network in order to produce colorless Glasses results in a drastic increase of their water contamination. We report for the first time, to the best of our knowledge, the purification of cesium chloride CsCl by dynamic distillations under vacuum in order to reduce water and hydroxyl group contamination before complete melting of the glass. Besides, sulfur purification by dynamic and static distillations was also performed in the implemented method. The obtained Glasses were then characterized by UV-visible and infrared (FTIR) spectroscopies, by electron probe microanalysis (EPMA), thermal analysis (DSC), and their refractive indices in the visible and near infrared ranges were also measured. A large improvement of the glass transmission spectrum has been achieved with an estimated reduction of about 45 times of the OH and H2O content and 60 times of the SH content. The glass thermal molding ability and chemical durability with and without protective coating have been tested to probe their potential for fabrication of complex optics.
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71Ga NMR in chalcogenide and chalco-Halide Glasses
Journal of Non-Crystalline Solids, 2014Co-Authors: Yannick Ledemi, Bruno Bureau, Gérard Le Caër, Laurent Calvez, Claire Roiland, Grégory Tricot, Pierre Florian, Virginie Nazabal, Dominique MassiotAbstract:Chalcogenide and chalco-Halide Glasses containing gallium have been studied through 71Ga solid state nuclear magnetic resonance (NMR). An unusual line shape of the 71Ga NMR spectra has been observed for the first time. This line shape was ascribed to the preferential local symmetry existing around gallium atoms in these Glasses which are characterized by the covalent character of their chemical bonds. Then, the local environment of gallium in Ga2S3-GeS2-CsCl Glasses was studied by 71Ga NMR as a function of the ionic cesium chloride CsCl concentration. In this system, CsCl directly interacts with Ga by forming anionic complexes, modifying its environment. The Czjzek's electric field gradient distribution and its recent extension have been successfully applied to reconstruct the experimental 71Ga NMR spectra. These results highlight the evolution of local surroundings of Ga atoms in the glass network as a function of the CsCl concentration.
Mark Andrew Newhouse - One of the best experts on this subject based on the ideXlab platform.
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praseodymium doped cadmium mixed Halide Glasses for 1 3 μm amplification
Journal of Non-crystalline Solids, 1995Co-Authors: Roger F. Bartholomew, Bruce G. Aitken, Mark Andrew NewhouseAbstract:Abstract In the search for suitable glass hosts for 1300 nm amplification, the field has been narrowed to Pr-doped fluorozirconate, fluoroindate, cadmium mixed Halide and sulphide Glasses. This paper presents data identifying the cadmium mixed Halide system as a leading candidate, based on the lifetime and quantum efficiency of the1G4 →3H5 fluorescence of Pr3+ in this system. Compositional studies to develop cladding and core Glasses suitable for high numerical aperture fiber, as well as relevant physical and optical properties, are also discussed.
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Pr-doped mixed-Halide Glasses for 1300 nm amplification
IEEE Photonics Technology Letters, 1994Co-Authors: Mark Andrew Newhouse, Roger F. Bartholomew, Bruce G. Aitken, L. J. Button, Nicholas F. BorrelliAbstract:The pump efficiency of Pr-doped fluorozirconate amplifiers at 1300 nm is limited by nonradiative decay. A Pr/sup 3+1/G/sub 4/ excited state lifetime of 322 /spl mu/s has been obtained in a mixed-Halide glass. This is 2.9 times longer than the lifetime in a fluorozirconate host. Numerical amplifier modeling combined with calculated emission cross sections predicts a comparable increase in amplifier pump efficiency. The mixed-Halide /sup 1/G/sub 4/ emission is peaked at 1310 nm. >
Mingxing Zhu - One of the best experts on this subject based on the ideXlab platform.
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Research on the correlation between the optical gap and chemical bond in sulphur and selenium co-doped chalco-Halide Glasses.
Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy, 2010Co-Authors: Mingxing Zhu, Qiuhua Nie, Xunsi Wang, Shixun Dai, Xianghua Zhang, Xiang Shen, Guoxiang WangAbstract:The Ge-Ga-Se-S-CsCl Glasses were prepared by the melting-quenching method. The absorption and transmission spectrum were measured under room temperature. It is found that these Glasses have high broad spectral range of transparency from visible to far-infrared region (0.4-12 microm). The relationship between the optical gap and chemical composition in terms of novel chalco-Halide Glasses is discussed based on the Pauling's theory model, which is using the modified heats of atomization and the coordination number of the elements, to explain this phenomena for the first time.
