A novel cladding-mode coupler formed by long period fiber gratings and microsphere resonator

There are numerous methods for evanescently coupling energy into the modes of a sphere. In this paper, we provided a new methods, used long period fiber gratings (LPFG) coupling evanescent wave into microsphere resonator. We have illustrated this coupling mechanism in theoretical. As an potentially application, we describe a four-port passive Add/Drop device based on the microsphere-LPFG coupling mechanism

Design and fabrication of an all fiber-optical add/drop element based on a taper-resonator-taper structure

In this letter, we designed and fabricated an all fiber-optic Add/Drop element based on Taper-Resonator-Taper (TRT) structure, assembling it with V-shaped grooves. We proposed a novel configuration composed of two microspheres and three taper fibers. We can cascade this kind of TRT structure, it will be potentially used as multi-wavelengths Optical Add/Drop Multiplexer and Wavelength Division Multiplexer/Demultiplexer

Low loss coatings for the VIRGO large mirrors

présentée par L. PinardThe goal of the VIRGO program is to build a giant Michelson type interferometer (3 kilometer long arms) to detect gravitational waves. Large optical components (350 mm in diameter), having extremely low loss at 1064 nm, are needed. Today, the Ion beam Sputtering is the only deposition technique able to produce optical components with such performances. Consequently, a large ion beam sputtering deposition system was built to coat large optics up to 700 mm in diameter. The performances of this coater are described in term of layer uniformity on large scale and optical losses (absorption and scattering characterization). The VIRGO interferometer needs six main mirrors. The first set was ready in June 2002 and its installation is in progress on the VIRGO site (Italy). The optical performances of this first set are discussed. The requirements at 1064 nm are all satisfied. Indeed, the absorption level is close to 1 ppm (part per million), the scattering is lower than 5 ppm and the R.M.S. wavefront of these optics is lower than 8 nm on 150 mm in diameter. Finally, some solutions are proposed to further improve these performances, especially the absorption level (lower than 0.1 ppm) and the mechanical quality factor Q of the mirrors (thermal noise reduction)

Systèmes d'élevage et d'alimentation à base de fourrages pour les chevaux

7 graph.National audienceHorses can make use of plant resources in temperate climates in feeding systems based on preserved forages and grazing to produce horses for sport, leisure or meat. Feeding systems for the brood mare herd are described in good grassland conditions or in upland conditions, In harsh conditions, utilisation of the body reserves by mares during the production cycle allows them to maintain the management herd system and to produce heavy foals, Growing horses can be fed different types of diets based on forages during winter periods, The level of concentrate supplementation in the diet can regulate the growing performances according to the horse type, Heavy breed foals, intended for meat production, make use of diets based on forages and grass with different energy supplementations according to their slaughter age and expected body condition, The ability of the horse to be managed in high forage feeding systems is explained in a major part by the distinctive features of the horse, which enable it to select, consume and digest forages and grazed resources, However, new knowledge is required on ingestive regulation and on feeding behaviour of horses, as they make more and more use of plant resources in extensive conditions.Les chevaux peuvent utiliser les ressources fourragères des climats tempérés dans le cadre de systèmes d’alimentation à base de fourrages conservés ou de pâturage destinés à produire des chevaux de sport, de loisir ou de viande. Les systèmes d’alimentation des troupeaux de poulinières de race de selle ou lourdes sont décrits en conditions favorables de plaine ou difficiles d’altitude. Dans les milieux contraignants, l’utilisation des réserves corporelles par les juments au cours de leur cycle de production permet d’assurer la pérennité du système de conduite et la production de poulains de race lourde. Durant les périodes hivernales, les chevaux en croissance de race de selle ou de trait peuvent être alimentés avec différents types de rations à base de fourrages dont la complémentation en concentrés permet d’ajuster les performances au type de production. Les poulains de races lourdes, destinés à la production de viande, utilisent des rations de fourrages conservés ou pâturés, dont la concentration énergétique varie selon l’âge à l’abattage et l’état d’engraissement recherchés. La capacité des chevaux à valoriser des fourrages très différents dans des systèmes d’alimentation variés s’explique dans une large mesure par leurs spécificités d’herbivore pour sélectionner, ingérer et digérer les fourrages et l’herbe au pâturage. Cependant l’acquisition de connaissances nouvelles est nécessaire sur les phénomènes de régulation de l’ingestion et du comportement alimentaire de ces types d’animaux, de plus en plus utilisateurs de ressources végétales extensives