Chalcogenide Glass Optical Waveguides for Infrared Biosensing

Due to the remarkable properties of chalcogenide (Chg) glasses, Chg optical waveguides should play a significant role in the development of optical biosensors. This paper describes the fabrication and properties of chalcogenide fibres and planar waveguides. Using optical fibre transparent in the mid-infrared spectral range we have developed a biosensor that can collect information on whole metabolism alterations, rapidly and in situ. Thanks to this sensor it is possible to collect infrared spectra by remote spectroscopy, by simple contact with the sample. In this way, we tried to determine spectral modifications due, on the one hand, to cerebral metabolism alterations caused by a transient focal ischemia in the rat brain and, in the other hand, starvation in the mouse liver. We also applied a microdialysis method, a well known technique for in vivo brain metabolism studies, as reference. In the field of integrated microsensors, reactive ion etching was used to pattern rib waveguides between 2 and 300 μm wide. This technique was used to fabricate Y optical junctions for optical interconnections on chalcogenide amorphous films, which can potentially increase the sensitivity and stability of an optical micro-sensor. The first tests were also carried out to functionalise the Chg planar waveguides with the aim of using them as (bio)sensors

New genetic loci link adipose and insulin biology to body fat distribution.

Body fat distribution is a heritable trait and a well-established predictor of adverse metabolic outcomes, independent of overall adiposity. To increase our understanding of the genetic basis of body fat distribution and its molecular links to cardiometabolic traits, here we conduct genome-wide association meta-analyses of traits related to waist and hip circumferences in up to 224,459 individuals. We identify 49 loci (33 new) associated with waist-to-hip ratio adjusted for body mass index (BMI), and an additional 19 loci newly associated with related waist and hip circumference measures (P < 5 × 10(-8)). In total, 20 of the 49 waist-to-hip ratio adjusted for BMI loci show significant sexual dimorphism, 19 of which display a stronger effect in women. The identified loci were enriched for genes expressed in adipose tissue and for putative regulatory elements in adipocytes. Pathway analyses implicated adipogenesis, angiogenesis, transcriptional regulation and insulin resistance as processes affecting fat distribution, providing insight into potential pathophysiological mechanisms

Verres de sulfures: spectroscopie des ions de terres-rares, fibres microstructurées et nouvelles compositions

J.L. ADAM Directeur de recherche CNRS, Université de Rennes 1, Rennes R. BALDA Professeur, Universidad del Paìs Vasco, Bilbao, Espagne D. BOSC Ingénieur de Recherche à l'ENSSAT, Université de Rennes 1, Lannion B. BOULARD Maître de conférence, Université du Maine, Le Mans Rapporteur A. BOURGET Directeur Général, UMICORE IR-Glass, Acigné B. JACQUIER Directeur de recherche CNRS, Université Claude Bernard-Lyon 1 RapporteurUsing originals materials, with high linear and non-linear indices of refraction and with low phonon energies, as sulfide glasses, allows new perspectives for telecommunication applications, such as large-band amplification (1.3-1.5 µm), all-optical switching and signal regeneration. In this report, we have studied optical fibres and glasses transmitting in the infrared range. The optical window of glasses based on GeGaS system, has been extended to the visible region, thanks to the addition of metal and earth-alkali chlorides. Physical properties (density, glass transition temperature, thermal expansion, micro-hardness, optical transmission, refractive index) and structural organization were studied in order to highlight the impact of chloride addition in sulfide glasses. Rare-earth-doped GeGaSbS sulfide glasses possess the potential for optical amplification in the 1.3 - 1.47 µm spectral region. The energy gap law, linking multiphonon relaxation rate to energy gap between an excited level and its next lower level, was established in GeGaSbS glasses. Energy-level diagram of Yb3+ ion in various sulfide and halogeno-sulfide glasses was established by studies of spectroscopic properties of this ion, in order to choose the best host for laser optical cooling. Drawing of single-mode fibres was investigated for GeGaSbS glasses. A single-mode sulfide fiber of numerical aperture of 0.44 has been prepared and has shown a mode diameter of 2 µm at 1.55 µm. Infrared fluorescence of Dy3+ and Tm3+ on multimode fiber was studied too. Microstructured fibers have been realized with GeGaSbS-sulfide-glasses which can be easily shaped and drawn. Holey fiber, quasi single-mode at 1.55 µm, was demonstrated.L'utilisation de matériaux originaux, à forts indices de réfraction linéaires et non-linéaires et à faibles énergies de phonon, tels que les verres de sulfures, permet d'envisager des applications comme l'amplification large bande (1,3-1,5 µm), la régénération et la commutation tout-optique en télécommunication. Les travaux de recherche présentés ici concernent l'étude de fibres optiques et verres de chalcogénures transmettant dans l'infrarouge. La fenêtre optique des verres appartenant au système de référence GeGaS a été élargie dans le domaine du visible par addition de chlorures de métaux et d'alcalino-terreux. Les caractérisations physico-chimiques en termes de propriétés thermiques, optiques, de durabilité chimique et l'étude de l'organisation structurale des compositions mettent en lumière l'impact de l'insertion d'halogènes dans les verres de sulfures. Les verres de sulfures du système Ge-Ga-Sb-S présentent une potentialité pour l'amplification optique entre 1,3 et 1,47 µm par dopage terre-rare. La loi du gap, établissant la probabilité de relaxation multiphonon à l'écart d'énergie entre un niveau excité et un niveau immédiatement inférieur, a été démontrée dans les verres de sulfures du système GeGaSbS. L'étude des propriétés spectroscopiques de Yb3+ dans différentes matrices sulfures et halogéno-sulfures a permis d'établir le diagramme d'énergie de l'ytterbium dans chacune de ces matrices et de choisir celle la plus adaptée aux études de refroidissement optique. Les verres du système GeGaSbS ont fait l'objet d'études de mise en forme. Une fibre monomode, d'ouverture numérique 0,44 et de diamètre de mode 2 µm a été obtenue et caractérisée à la longueur d'onde de 1,55 µm. La fluorescence infrarouge du dysprosium et du thulium sur des fibres multimode a été étudiée. La bonne aptitude de ces verres au fibrage a conduit à la réalisation de fibres microstructurées, de types bande interdite photonique et à trous. La caractérisation optique de ces fibres a révélé le caractère quasi-monomode d'une des fibres à trous à la longueur d'onde de 1,55 µm

Verres de sulfures (spectroscopie des ions de terres-rares, fibres microstructurées et nouvelles compositions)

L'utilisation de matériaux originaux, à faibles énergies de phonons, tels que les verres de sulfures, permet d'envisager des applications dans le domaine des télécommunications.Ainsi, La fenêtre optique des verres appartenant au système de référence GeGaS a été élargie dans le domaine du visible par addition de chlorure de métaux et d&rsquo;alcalino-terreux. Dans le cadre d'études de refroidissement optique, le diagramme d&rsquo;énergie de l'ytterbium a été établi dans les matrices sulfures et halogéno-sulfures. La loi empirique du gap a été démontrée dans les verres de sulfures du système GeGaSbS. Une fibre monomode de diamètre de mode 2 microns a été obtenue et caractérisée à 1,55 microns. La fluorescence infrarouge du dysprosium et du thulium sur des fibres multimode a été étudiée. Des fibres microstructurées en verres de sulfures, de types bande interdite photonique et à trous, ont été réalisées. La caractérisation optique de ces fibres a révélé le caractère quasi-monomode d&rsquo;une des fibres à trous à 1,55 microns.RENNES1-BU Sciences Philo (352382102) / SudocSudocFranceF

Holey optical fibers based on chalcogenide glasses

International audienc

Light guidance in new chalcogenide holey fibres from GeGaSbS glass

International audienceHoley fibres have a broad range of optical properties thanks to their microstructuration and offer a wide range of applications. The combination of intrinsic properties of compound glass, such as chalcogenide glass, and a microstructured fibre geometry allows to consider exacerbated optical properties such as dispersion and nonlinearity for these fibres. In this study, high-index sulphide glass holey fibres (n = 2.251 at 1.55 μm) have been accomplished using the capillary-stacking technique. Sulphide glasses from the GeGaSbS system are used. The drawing step is crucial for microstructuration and for determination of optical properties. Sulphide holey fibres, which were optically characterised with near-field spectroscopy at 1.55 μm, show a single-mode guidance with an effective mode area of 108 μm2

Chalcogenide waveguide for IR optical range

International audienceDue to remarkable properties of the chalcogenide glasses, especially sulphide glasses, amorphous chalcogenide films should play a motivating role in the development of integrated planar optical circuits and their components. This paper describes the fabrication and properties of optical waveguides of pure and rare earth doped sulphide glass films prepared by two complementary techniques: RF magnetron sputtering and pulsed laser deposition (PLD). The deposition parameters were adjusted to obtain, from sulphide glass targets with a careful control of their purity, layers with appropriate compositional, morphological, structural characteristics and optical properties. These films have been characterized by micro-Raman spectroscopy, atomic force microscopy (AFM), X-ray diffraction technique (XRD) and scanning electron microscopy (SEM) coupled with energy dispersive X-ray measurements (EDX). Their optical properties were measured thanks to m-lines prism coupling and near field methods. Rib waveguides were produced by dry etching under CF4, CHF3 and SF6 atmosphere. The photo-luminescence of rare earth doped GeGaSbS films were clearly observed in the n-IR spectral domain and the study of their decay lifetime will be presented. First tests were carried out to functionalise the films with the aim of using them as sensor

Defining the role of common variation in the genomic and biological architecture of adult human height

Using genome-wide data from 253,288 individuals, we identified 697 variants at genome-wide significance that together explained one-fifth of the heritability for adult height. By testing different numbers of variants in independent studies, we show that the most strongly associated ∼2,000, ∼3,700 and ∼9,500 SNPs explained ∼21%, ∼24% and ∼29% of phenotypic variance. Furthermore, all common variants together captured 60% of heritability. The 697 variants clustered in 423 loci were enriched for genes, pathways and tissue types known to be involved in growth and together implicated genes and pathways not highlighted in earlier efforts, such as signaling by fibroblast growth factors, WNT/β-catenin and chondroitin sulfate-related genes. We identified several genes and pathways not previously connected with human skeletal growth, including mTOR, osteoglycin and binding of hyaluronic acid. Our results indicate a genetic architecture for human height that is characterized by a very large but finite number (thousands) of causal variants