NGUYEN , Luan

Identifying human characters and how they are portrayed on-screen is inherently linked to how we perceive and interpretthe story and artistic value of visual media. Building computational models sensible towards story will thus require a formalrepresentation of the character. Yet this kind of data is complex and tedious to annotate on a large...

Les fibres optiques céramiques permettent de combiner les propriétés mécaniques d'un matériau amorphe et les propriétés spectroscopiques d'un environnement qui peut être cristallin ou amorphe. Dans cette communication, nous présentons une méthode de nanostructuration de fibres optiques à base de silice où l'introduction de magnésium dans la...

Le développement de nouvelles fibres optiques amplificatrices nécessite de s'affranchir des limitations spectroscopiques imposées par la silice. Pour cela, nous avons choisi d'encapsuler les ions luminescents dans des nano-particules d'oxyde. Elles sont obtenues par séparation de phase déclenchée par des cycles thermiques nécessaires a la...

In this contribution, we performed the growth of a 3C-SiC/Si/3C-SiC layer stack on a Si(001) substrate by means of chemical vapor deposition. We show that, by tuning the growth conditions, the 3C-SiC epilayer can be grown along either the [111] direction or the [110] direction. The key parameter for the growth of the desired 3C-SiC orientation...

Rare earth (RE) doped silica-based optical fibers with transparent glass ceramic (TGC) core was fabricated through the well-known modified chemical vapor deposition (MCVD) process without going through the commonly used stage of post-ceramming. The main characteristics of the RE-doped oxyde nanoparticles namely, their density and mean diameter...

DNP are observed in fibres when alkaline-earth elements (Mg, Ca and Sr) are incorporated. Mean size of the DNP, deduced from SEM pictures, depends on the composition... This last composition leads to a low loss fibre... From EDX measurements, we have observed that alkaline-earth elements and erbium ions are located inside or very close to the...

Chemical vapor deposition (CVD) with hydrogen is an interesting technique to grow graphene on silicon carbide (SiC) with excellent electronic properties. However, unanswered questions remain concerning whether the growth mechanism is similar or different to the graphene growth by silicon (Si) sublimation from SiC. In this paper, we emphasize...

We present an epitaxy-based approach for designing a 3C-SiC Capacitive Micromachined Ultrasonic Transducer (CMUT). The design requires to consider a 3C-SiC/Si/3C-SiC heterostructure on a Si substrate. This implies to address different growth steps of SiC on Si and Si on SiC. We present some specific growth related issued, namely the control of...

Optical properties of GaN templates grown by the Epitaxial Lateral Overgrowth (ELO) technique along the nonpolar (1120) and the semipolar (1122) directions on R- and M-sapphire were investigated. Spatially resolved Cathodoluminescence (CL) was carried out in order to identify defect related transitions, to resolve their localization and to...

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(111)-oriented cubic polytypes of silicon carbide (3C-SiC) films were grown by chemical vapor deposition on 2H-AlN(0001)/Si(111) and 2H-AlN(0001)/Si(110) templates. The structural and electrical properties of the films were investigated. For film thicknesses below 300 nm, the 3C-SiC material deposited on 2H-AlN/Si presented a better structural...

Herein, the interest of cubic silicon carbide as a template for the growth of AlGaN/ GaN high electron mobility transistor (HEMT) heterostructures on silicon substrates for high-frequency operation is shown. On the one hand, 0.6-0.8 μm-thick 3C-SiC grown by chemical vapor deposition on intrinsic silicon substrate having initial resistivity...

Herein, the interest of cubic silicon carbide as a template for the growth of AlGaN/ GaN high electron mobility transistor (HEMT) heterostructures on silicon substrates for high-frequency operation is shown. On the one hand, 0.6-0.8 μm-thick 3C-SiC grown by chemical vapor deposition on intrinsic silicon substrate having initial resistivity...

The H2MEMS project aims at developing and optimizing hydrogen sensors based on resonant MEMS for detection of hydrogen release in radioactive waste disposal facility. The principle adopted is based on measuring physical properties of the gas (mass density, viscosity, sound velocity and sound absorption) without requiring any sensitive layer....