Contribution a l’aménagement d’installations pour les espèces asiatiques d’un parc zoologique : application au projet d’agrandissement du parc zoologique de Plaisance-du-Touch (Haute-Garonne)

Le travail réalisé dans cette thèse a pour origine le projet d’agrandissement du parc zoologique de Plaisance-du-Touch. Il s’agit, à partir d’une liste d’animaux d’Asie fournie au préalable, de proposer des aménagements pour le maintien de ces espèces au sein du parc. Les animaux ont tout d’abord été regroupés en fonction de 4 grandes zones bioclimatiques correspondant à un découpage pratique du continent asiatique. Nous avons ensuite effectué un recueil de données sur la biologie de ces espèces et sur les recommandations connues pour le maintien de celles-ci en captivité. Enfin, pour toutes ces espèces, nous avons fait des propositions illustrées d’aménagements d’enclos, privilégiant l’originalité et tenant compte à la fois des recommandations en terme de bien-être animal, des mesures de sécurité, de critères de visibilité pour le visiteur et des exigences du parc

Body surface rewarming in fully and partially hypothermic king penguins

Penguins face a major thermal transition when returning to land in a hypothermic state after a foraging trip. Uninsulated appendages (flippers and feet) could provide flexible heat exchange during subsequent rewarming. Here, we tested the hypothesis that peripheral vasodilation could be delayed during this recovery stage. To this end, we designed an experiment to examine patterns of surface rewarming in fully hypothermic (the cloaca and peripheral regions (here; flippers, feet and the breast) < 37 °C) and partially hypothermic (cloaca at normothermia ≥ 37 °C, but periphery at hypothermia) king penguins (Aptenodytes patagonicus) when they rewarmed in the laboratory. Both groups rewarmed during the 21 min observation period, but the temperature changes were larger in fully than in partially hypothermic birds. Moreover, we observed a 5 min delay of peripheral temperature in fully compared to partially hypothermic birds, suggesting that this process was impacted by low internal temperature. To investigate whether our laboratory data were applicable to field conditions, we also recorded surface temperatures of free-ranging penguins after they came ashore to the colony. Initial surface temperatures were lower in these birds compared to in those that rewarmed in the laboratory, and changed less over a comparable period of time on land. This could be explained both by environmental conditions and possible handling-induced thermogenesis in the laboratory. Nevertheless, this study demonstrated that appendage vasodilation is flexibly used during rewarming and that recovery may be influenced by both internal temperature and environmental conditions when penguins transition from sea to land

LiNbO3 ridge waveguides realized by precision dicing on silicon for high efficiency second harmonic generation

Nonlinear periodically poled ridge LiNbO3 waveguides have been fabricated on silicon substrates. Components are carved with only use of a precision dicing machine without need for grinding or polishing steps. They show efficient second harmonic generation at telecommunication wavelengths with normalized conversion reaching 204%/W in a 15 mm long device. Influence of geometrical non uniformities of waveguides due to fabrication process is asserted. Components characteristics are studied notably their robustness and tunability versus temperature.Comment: 10 pages, 10 figure

Guides optiques accordables électriquement

International audienceDes guides d'onde accordables électriquement ont été fabriqués dans des films minces de LiNbO3 sur substrat de silicium par inversion de domaines. L'effet électro-optique est exploité pour induire les guides et pour contrôler leurs propriétés de guidage. Ainsi, une tension de quelques volts permet de faire apparaitre un guide efficace à 1.55μm ou au contraire de générer un anti-guide. La transmission des dispositifs fabriqués peut ainsi varier sur plus de 25dB. La réponse en fréquence des composants permet d’envisager des modulations rapides

Voltage-induced waveguides in lithium niobate films on silicon substrates

International audienceElectrically tunable channel waveguides have been fabricated by domain inversion of a LiNbO3 thin film bonded to a silicon wafer. The electro-optic effect is used to induce the waveguides and to alter its guiding properties. A low amplitude electric signal can tune the voltage-induced structure from an efficient waveguide to an antiguide giving a waveguide transmission that varies over more than 25 dB. The frequency response of the components is given

Step-index LiNbO3 waveguides for frequency conversion

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Fast light self-trapping in isolated LiNbO3 slab waveguide by pyroelectric effect

International audienceBeam self-trapping by pyroelectric effect is reported in a LiNbO3 film. The underlying physics specific to this arrangement is especially characterized by a response time orders of magnitude faster than in bulk LiNbO

Single photon MIR upconversion detector at room temperature with a PPLN ridge waveguide

International audienceIn this paper we describe an upconversion detector in the mid infrared (around 3.5 μm). We take advantage of the PPLN ridge waveguide technology to achieve single photon detection at room temperature on a single spatial mode. With a pump power of 192 mW we obtain a detection efficiency of 0.4% for 22k dark count per second, which corresponds to a noise equivalent power of 3.0 fW · Hz−1/2 and an internal conversion efficiency of 85 %/W of pump

Ridge optical waveguide curved in a KTiOPO4 single crystal for triple photon generation: preliminary characterization by birefringence phase-matched third-harmonic generation

International audienceRidge waveguides carved in bulk nonlinear crystals such as KTiOPO4 (KTP) are used to reach a strong confinement of electromagnetic waves with large second-order or third-order non-linearity. We report on our recent experiments where we show the possibility to shape the birefringence phase-matching (BPM) conditions for direct Third-Harmonic Generation (THG: ω + ω + ω → 3ω) in micrometric KTP ridge waveguides by acting on their transverse dimensions. The real goal of this preliminary study is to design quantum optical experiments based on Triple Photons Generation (TPG: 3ω → ω + ω + ω) that is the reverse process of THG, thus exhibiting the same BPM conditions