References of "Renotte, Yvon"
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See detailThermo-optical properties of colloidal solutions of CdTe nanoparticles
Rosso, Vanessa ULg; Loicq, Jerôme ULg; Galstian, T. et al

in Optical Materials (2006), 28(8-9), 1041-1046

Colloidal solutions of CdTe nanoparticles have been prepared by the "electropulse" technique. The diameters of the CdTe nanoparticles range from 5 to 30 nm. The goal of this work is to study the formation ... [more ▼]

Colloidal solutions of CdTe nanoparticles have been prepared by the "electropulse" technique. The diameters of the CdTe nanoparticles range from 5 to 30 nm. The goal of this work is to study the formation and evolution of the induced thermo-refractive index with a long-term goal of forming a thermal lens. An induced thermo-refractive index occurs when the CdTe solutions are irradiated with a strong laser beam. The experimental approach is derived from the Z-scan technique, a technique which is very sensitive to refractive index modulation in a sample. Thermo-optical coefficients, such as the thermal diffusivity, D, the characteristic build-up time of the thermal lens, t(c), and the induced thermo-refractive index can be determined from dynamic Z-scan curves. The thermo-optical coefficients have been determined at different wavelengths, beam powers, and for different nanoparticles sizes. (C) 2005 Elsevier B.V. All rights reserved. [less ▲]

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See detailOut-of-plane displacement derivative measurement: comparison of results obtained by a shearographic interferometer using the separation of the polarization states and the finite element method
Rosso, Vanessa; Zhang, Lihong ULg; Michel, Fabrice ULg et al

in Mathieu, P. (Ed.) Proceedings of Photonics North Conference 2006 (2006)

An original experimental setup for shearography with metrological applications is presented herein. The simplicity and the efficiency of the setup are provided by a shearing device, a prism that separates ... [more ▼]

An original experimental setup for shearography with metrological applications is presented herein. The simplicity and the efficiency of the setup are provided by a shearing device, a prism that separates the TE and TM polarization modes with a coating and a thin glass plate attached on its face. The temporal phase shifting method is applied through the use of a liquid crystal variable retarder. The use of this shearing device enables an in-line and almost-common path configuration for the shearing interferometer, a path that leads to high stability of the interferometer and a low sensitivity to external disturbances. In order to prove the efficiency and the accuracy of this speckle shearing interferometer, the out-of-plane displacement derivative relative to the shearing interferometry direction of a centrally loaded steel plate has been measured by the shearographic interferometer and then compared with the out-of-plane displacement derivative computed from the displacement field provided by the finite element method. The results are in good agreement. [less ▲]

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See detailThe nonlinear optical, magnetic, and Mossbauer spectral properties of some iron(III) doped silica xerogels
Rebbouh, L.; Rosso, Vanessa ULg; Renotte, Yvon ULg et al

in Journal of Materials Science (2006), 41(10), 2839-2849

Iron(III) species dispersed in silica have been synthesized with a sol-gel process. The iron(III) was introduced as the acetylacetonate complex into a solution of tetraethoxysilane to yield, after ... [more ▼]

Iron(III) species dispersed in silica have been synthesized with a sol-gel process. The iron(III) was introduced as the acetylacetonate complex into a solution of tetraethoxysilane to yield, after evaporative drying, pellets or monoliths. Two gels were dried very slowly over a period of five months in order to prepare a defect free monolith useful for nonlinear optical studies. Z-scan experimental studies on the resulting, transparent, monolithic, doped solid revealed an optical Kerr effect, a third order nonlinear optical phenomenon showing a linear dependence of the refractive index on the irradiance with a nonlinear refractive index, n(2), of -1.95 x 10(-11) cm(2)/W. Magnetic susceptibility studies between 4.2 and 295 K revealed paramagnetic behavior with a Curie constant of 4.433 (emu/mol)K and a Weiss temperature of -7.1 K. Magnetization studies at 5 K and at applied fields of up to 4 T and Mossbauer spectral studies between 4.2 and 295 K revealed a 50:50 mixture of paramagnetic species and nanoparticles with an average particle radius of 1.3 +/- 0.2 nm. A blocking temperature of 70 K and a magnetic anisotropy energy of 2.4 x 10(5) J/m(3) stop are derived from the Mossbauer spectra. (c) 2006 Springer Science + Business Media, Inc. [less ▲]

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See detailHigh transmission efficiency for surface plasmon resonance by use of a dielectric grating
Lenaerts, Cedric ULg; Michel, Fabrice ULg; Tilkens, Bernard et al

in Applied Optics (2005), 44(28), 6017-6022

The efficiency of the transmission of surface plasmon waves by use of a dielectric diffraction grating is discussed. The Kretschmann device allows us to obtain a surface plasmon resonance that consists of ... [more ▼]

The efficiency of the transmission of surface plasmon waves by use of a dielectric diffraction grating is discussed. The Kretschmann device allows us to obtain a surface plasmon resonance that consists of an absorption peak in the reflection spectrum. When surface plasmon resonance occurs, the TM-polarization mode of the incident electromagnetic wave is neither transmitted nor reflected. The procedure to transform an absorption peak into a transmission peak is described. Transmittivity of 68% is obtained for a simple structure that consists of a thin-film layer of Ag coated on a volume diffraction grating and embedded between two dielectric media. The results presented herein were obtained by numerical simulations that were carried out by use of an algorithm based on the rigorous coupled-wave theory. [less ▲]

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See detailInterferometric fringes projection system for 3D profilometry and relief investigation
Moreau, Vincent; Laboury, Dimitri ULg; Tilkens, Bernard et al

in Optical Methods for Arts and Archaeology, Proceedings of SPIE, Vol. 5857 (2005)

We present a new 3D full-frame profilometer based on structured laser light projection method. This device takes advantage of the polarization states splitting technique for producing and shifting ... [more ▼]

We present a new 3D full-frame profilometer based on structured laser light projection method. This device takes advantage of the polarization states splitting technique for producing and shifting multiple sinusoidal Young’s interference patterns that are projected on the inspected surface. The principle of the technique is presented and we discuss the advantages of monochromatic light projection method as a mean to overcome ambient lighting for in-situ measurement. Some results that we obtained on objects from the Egyptian Department of the British Museum are presented to demonstrate that 3D laser profilometry is a worthwhile technique for epigraphic investigations where naked-eye inspections fail. [less ▲]

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See detailAt the crossing of physics and Aercheology : the OSIRIS project
Renotte, Yvon ULg; Laboury, Dimitri ULg; Tilkens, Bernard et al

in Europhysics News (2004), 35/6

How physics can help aercheology, including a path to the parket

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See detailNarrow band-width wavelength filter by guided mode resonance
Lenaerts, Cedric ULg; Moreau, Vincent; Renotte, Yvon ULg et al

in Optical Engineering : The Journal of the Society of Photo-Optical Instrumentation Engineers (2004), 43(11), 2631-2639

Simple resonant structures that permit holographic reflection filtering are studied. The filters under study work under a 45-deg incidence for a wavelength of λ=632.8 nm, a condition useful for future ... [more ▼]

Simple resonant structures that permit holographic reflection filtering are studied. The filters under study work under a 45-deg incidence for a wavelength of λ=632.8 nm, a condition useful for future inclusion in substrate mode systems. First, the influence of the structural parameters of the grating and the waveguide on the position and the shape of the resonance peaks are studied by numerical computation. The numerical results, obtained within the rigorous coupled wave theory, are compared with the measured response of some filters. These filters contain a grating recorded by holography deposited on the substrate. In the case of the bilayer filter, a waveguide is introduced between the grating and the substrate. Second, the numerical results are used for the conception of an active substrate mode spectral filter built from electro-optic zinc oxide. [less ▲]

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See detailOptical non-linearity in disperse red 1 dye-doped sol-gel
Rosso, Vanessa ULg; Loicq, Jerôme ULg; Renotte, Yvon ULg et al

in Journal of Non-Crystalline Solids (2004), 342(1-3), 140-145

A third-order non-linear optical effect, the optical Kerr effect, was studied in DR1-doped sol-gel using the Z-scan method which allows studying both processes of non-linear absorption and refraction. The ... [more ▼]

A third-order non-linear optical effect, the optical Kerr effect, was studied in DR1-doped sol-gel using the Z-scan method which allows studying both processes of non-linear absorption and refraction. The materials under study are sol-gel substrates, amorphous silica glasses doped by the azo-dye Disperse Red 1. Modifying the conditions of the sol-gel synthesis, in particular the pH of the catalytic medium, enabled us to vary the morphology of the sol-gel substrate. Non-linear effects of various amplitudes were observed in so-gel substrates of various porosities, involving different non-linear mechanisms. (C) 2004 Elsevier B.V. All rights reserved. [less ▲]

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See detailNon-linear optical measurements and crystalline characterization of CdTe nanoparticles produces by thes electropulse technique
Loicq, Jerôme ULg; Renotte, Yvon ULg; Delplancke, Jean-Luc

in New Journal of Physics (2004), 6(32),

We propose to extend the ‘electropulse’ technique to synthesize CdTe nanoparticles for optical components. To do so, we create nuclei of the expected material on a titanium electrode immersed in an ... [more ▼]

We propose to extend the ‘electropulse’ technique to synthesize CdTe nanoparticles for optical components. To do so, we create nuclei of the expected material on a titanium electrode immersed in an electrolytic solution by using an electrochemical pulse. The nanoparticles are expelled from the titanium horn surface by cavitation bubbles, which are produced in the solution by a high intensity ultrasound pulse generated by a piezoelectric crystal. Optical absorption spectra and third-order non-linear optical properties of a colloidal solution of CdTe particles produced by this technique are presented. The non-linear refractive index was characterized using the single-beam z-scan technique, and measurements were carried out at several incidence intensities. Non-linear indices of refraction between −1.2×10−7 and −2×10−8 cm2W−1 were measured. [less ▲]

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See detailAchromatic four quadrants phase mask coronagraph using the dispersion of form birefringence
Mawet, Dimitri; Lenaerts, Cedric ULg; Moreau, Vincent et al

in Society of Photo-Optical Instrumentation Engineers (SPIE) Conference Series (2003, February 01)

We describe an alternative design for the 4-quadrant phase mask coronagraph described recently by Rouan et al. 2000. Based on the same principle, i.e. producing a very efficient nulling by mutually ... [more ▼]

We describe an alternative design for the 4-quadrant phase mask coronagraph described recently by Rouan et al. 2000. Based on the same principle, i.e. producing a very efficient nulling by mutually destructive interferences of the coherent light from the main source, our mask realises the pi phase shift using some properties of ZOGs (Zeroth Order Gratings) and according to an original scheme respecting the 4-quadrant symmetry. When the period of the one-dimension grating structure is smaller than the wavelength of the incident light, the structure becomes birefringent. The effective refractive indices depend on the wavelength. Using this feature, we can design a mask whose nulling e±ciency is maintained within a wide wavelength range. Numerical simulations were made according to the RCWT (Rigorous Coupled Wave Theory). [less ▲]

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See detailThe OSIRIS Project (Optical Systems for Interferometric-Photogrammetric Relief Investigation and Scanning). Development of a device for 3D numerical recording of archaeological and epigraphic documents by optoelectronic processes
Laboury, Dimitri ULg; Renotte, Yvon ULg; Tilkens, Bernard et al

in Boehler, Wolfgang (Ed.) PROCEEDINGS OF THE CIPA WG 6 INTERNATIONAL WORKSHOP ON SCANNING FOR CULTURAL HERITAGE RECORDING (2002, September)

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See detailCustomization of a self-processing polymer for obtaining specific diffractive optical elements
Carre, C.; Saint-Georges, Philippe ULg; Lenaerts, Cedric ULg et al

in Synthetic Metals (2002), 127

Photopolymerizable materials are capable of recording volume holograms via a change in refractivity of the layer. On illumination by an interference pattern around 500 nm, polymerization and diffusion led ... [more ▼]

Photopolymerizable materials are capable of recording volume holograms via a change in refractivity of the layer. On illumination by an interference pattern around 500 nm, polymerization and diffusion led to regions with various segment densities. A modulation of the refractive index took place, thus giving rise to permanent thick phase gratings created in situ in the emulsion. This modulation was estimated at 7 x 10(-3), corresponding to diffraction efficiencies of ca. 80% for transmission holography. Applications for the fabrication of diffractive optical elements can be expected in view of the experimental results and the simplicity of use. For instance, the duplication of computer-generated holograms on a photopolymerizable film led to thick phase holograms with higher diffraction efficiencies. Substrate-mode polarizing elements were also produced, taking advantage of the laminated property since this emulsion was embedded between two glass plates. (C) 2002 Elsevier Science B.V. All rights reserved. [less ▲]

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