References of "Lemaire, Philippe"
     in
Bookmark and Share    
Full Text
See detailMesure de coefficient de dilatation thermique de matériaux composites par holographie dynamique
Georges, Marc ULg; Ryhon, S.; Thizy, Cédric ULg et al

in Actes du 3e colloque francophone Méthodes et Techniques Optiques pour l'Industrie (2002, November)

Une méthode de mesure de coefficient de dilatation thermique par interférométrie holographique est présentée. Nous passerons rapidement en revue le principe de la caméra holographique dynamique utilisée ... [more ▼]

Une méthode de mesure de coefficient de dilatation thermique par interférométrie holographique est présentée. Nous passerons rapidement en revue le principe de la caméra holographique dynamique utilisée pour la mesure puis nous montrerons l’application à plusieurs cas concrets de R&D industriels. Il s’agit d’éprouvettes simples de matériaux composite et de structures plus complexes alliant ces matériaux à des métaux. La mesure consiste à observer le déplacement différentiel entre la partie supérieure de l’objet étudié et une plaque de base sur laquelle il est posé et ce lorsqu’un échauffement ou refroidissement de l’ensemble est opéré [less ▲]

Detailed reference viewed: 230 (0 ULg)
Full Text
Peer Reviewed
See detailMultiple exposure holographic interferometry with sillenite crystals applied to vibration measurement
Georges, Marc ULg; Thizy, Cédric ULg; Lemaire, Philippe ULg et al

in Nolte, D.; Salamo, G.; Siahmakoun, A. (Eds.) et al Photorefractive Effects, Materials, and Devices (2001, July)

A holographic camera is presented, which uses a sillenite crystal as dynamic recording medium. The camera operates in a pulse regime and is used to provide vibration analysis of an object. A 4 pulse real ... [more ▼]

A holographic camera is presented, which uses a sillenite crystal as dynamic recording medium. The camera operates in a pulse regime and is used to provide vibration analysis of an object. A 4 pulse real-time holographic technique was implemented to measure the amplitude and phase of the vibration. The implementation of this technique required bringing under control a Q-switched YAG laser. We present the experimental results for a metallic plate driven by a vibrating loud speaker. [less ▲]

Detailed reference viewed: 6 (1 ULg)
Full Text
Peer Reviewed
See detailCompact photorefractive holographic camera and its applications in interferometry
Georges, Marc ULg; Scauflaire, Véronique; Lemaire, Philippe ULg

in Nolte, D.; Salamo, G.; Siahmakoun, A. (Eds.) et al Photorefractive Effects, Materials, and Devices (2001, July)

A compact holographic interferometer that uses a photorefractive crystal of the sillenite family as holographic recording medium is presented. It was developed to provide high accuracy displacement ... [more ▼]

A compact holographic interferometer that uses a photorefractive crystal of the sillenite family as holographic recording medium is presented. It was developed to provide high accuracy displacement measurements of scattering objects, together with a high degree of flexibility, portability and versatility in function of the application. We briefly discuss the main technical aspects leading to a compact device. We present a couple of recent applications, among which the coefficient of thermal expansion of composite structures is measured, piezosheets calibration and fingerprint detection. [less ▲]

Detailed reference viewed: 4 (0 ULg)
Full Text
Peer Reviewed
See detailHolographic camera with BSO applied to microgravity fluid experiment aboard ISS
Georges, Marc ULg; Joannes, Luc; Thizy, Cédric ULg et al

in Nolte, D.; Salamo, G.; Siahmakoun, A. (Eds.) et al Photorefractive Effects, Materials, and Devices (2001, July)

We present the preliminary development steps of a holographic interferometer using a BSO crystal for the monitoring of fluids experiments under microgravity conditions. This set-up could be included in ... [more ▼]

We present the preliminary development steps of a holographic interferometer using a BSO crystal for the monitoring of fluids experiments under microgravity conditions. This set-up could be included in the Fluid Science Laboratory (FSL, a module dedicated to fluid physics experiment onboard the International Space Station-ISS). Some preliminary studies have been carried out. An optimized configuration has been found allowing a fast recording (50 milliseconds) and large number of readouts (>1000) for analysis of events over a long period without reducing the measurement resolution. We present examples of Rayleigh-Benard convection quantitative measurement performed with a laboratory instrument prototype. [less ▲]

Detailed reference viewed: 18 (2 ULg)
See detailUse of photorefractive materials for holographic recording : From crystal study to camera device in view of applied holographic interferometry
Lemaire, Philippe ULg; Georges, Marc ULg

in Lessard, Roger; Lampropoulos, George (Eds.) Applications of Photonic Technology 4 (2000, June)

We present a holographic camera based on a photorefractive crystal. A first prototype instrument has been studied and built on the basis of a broad optimization study. Some applications in high accuracy ... [more ▼]

We present a holographic camera based on a photorefractive crystal. A first prototype instrument has been studied and built on the basis of a broad optimization study. Some applications in high accuracy displacement/deformation metrology are presented. This first instrument generation was not completely portable and flexible of use. For that reason, a compact device has been designed and is presented. New applications of this holographic camera are shown. All theses achievements show the versatility and flexibility of utilization, as well as the high degree of user-friendliness, of a photorefractive crystal based holographic camera. Future prospects are then discussed [less ▲]

Detailed reference viewed: 9 (0 ULg)
Full Text
See detailHolographic photorefractive images storage for applied metrology by interferometry
Lemaire, Philippe ULg; Georges, Marc ULg

in Lagarde, A. (Ed.) Advanced Optical Methods and Applications in Solid Mechanics (2000)

Detailed reference viewed: 4 (0 ULg)
Full Text
Peer Reviewed
See detailTemperature variation of the photoinduced birefringence of an azo dye doped polymer
Blanche, Pierre-Alexandre ULg; Lemaire, Philippe ULg; Maertens, Christophe et al

in Polymer Engineering & Science (1999), 39(3), 406-412

The influence of the temperature on the photoinduced birefringence on an azo dye doped polymer film has been studied. Sample is composed of a polymer matrix PVK (Poly(N-vinylcarbazole)), doped with 10 ... [more ▼]

The influence of the temperature on the photoinduced birefringence on an azo dye doped polymer film has been studied. Sample is composed of a polymer matrix PVK (Poly(N-vinylcarbazole)), doped with 10 weight percent (wt%) of the birefringent molecule DMNPAA (2,5-dimethyl-4-(p-nitrophenylazo)anisole) and 30 wt% of ECZ (N-ethylcarbazole) which acts as a plasticizer. Theoretical results can explain the behavior of the amplitude of the photoinduced birefringence versus temperature. Experimental and theoretical results are compared. Holographic recording experiments based on photoinduced birefringence have been carried out. Based on the effect of temperature, we have been able to significantly increase the diffraction efficiency of our sample. [less ▲]

Detailed reference viewed: 33 (4 ULg)
Full Text
Peer Reviewed
See detailDynamics of the photo-induced orientation and relaxation of new polymethacrylates containing carbazolyl and azobenzene pendant groups
Maertens, Christophe; Dubois, Philippe ULg; Jérôme, Robert ULg et al

in Polymer International (1999), 48(3), 205-211

Polarized-light-induced birefringence has been investigated in copolymers of [-(N-carbazolyl)alkyl methacrylate] and [2,5-dimethylphenyl-[(4-nitrophenyl)azo]phenoxyalkyl methacrylate]. Optical properties ... [more ▼]

Polarized-light-induced birefringence has been investigated in copolymers of [-(N-carbazolyl)alkyl methacrylate] and [2,5-dimethylphenyl-[(4-nitrophenyl)azo]phenoxyalkyl methacrylate]. Optical properties of the side-chain copolymers have been compared with materials in which the azo-dye was merely dispersed in a poly[-(N-carbazolyl)alkyl methacrylate] matrix. Increasing the temperature of the film has a dramatic depressive effect on the maximum of photo-induced orientation near and above the glass transition temperature (Tg) region, while its effect was restricted under this temperature. Kinetics of the photo-orientation and the thermal relaxation as a function of temperature have been analysed by a biexponential model based on two rate constants. The universal Williams-Landel-Ferry (WLF) theory has been used to correlate the writing process and relaxation relative time constants with the relative temperature, i.e. T-Tg . The validity of this model for the studied materials leads to the assumption that photo-orientation and relaxation processes are mainly dependent on the free volume in the polymer matrix. This hypothesis has been assessed in the case of [11-(N-carbazolyl)undecyl methacrylate]-based materials. [less ▲]

Detailed reference viewed: 32 (3 ULg)
Full Text
Peer Reviewed
See detailSynthesis and electrooptic properties of a new chromophore dispersed or grafted in a carbazolyl methacrylate matrix
Maertens, Christophe; Detrembleur, Christophe ULg; Dubois, Philippe et al

in Chemistry of Materials (1998), 10

A copolymer of [11-(N-carbazolyl)undecyl methacrylate] and ethyl (E)-2-cyano-3[5-(5-(4-methacryloyloxy)piperidino-2-thienylcarbonyl)-2-thienyl]-2-propenoate has been prepared. The photoconductivity and ... [more ▼]

A copolymer of [11-(N-carbazolyl)undecyl methacrylate] and ethyl (E)-2-cyano-3[5-(5-(4-methacryloyloxy)piperidino-2-thienylcarbonyl)-2-thienyl]-2-propenoate has been prepared. The photoconductivity and the electrooptic properties of a hot-pressed thin film of this copolymer have been measured and compared with the properties of the dispersion of ethyl (E)-2-cyano-3[5-(5-piperidino-2-thienylcarbonyl)-2-thienyl]-2-propenoate within a poly[11-(N-carbazolyl)undecyl methacrylate] matrix. The electrooptic coefficient has been measured by both interferometric and polarimetric techniques. The interferometric technique was not appropriated because the strong electric field applied to the electrodes changes the film thickness of these low Tg materials. A value of up to 5 pm/V for the figure of merit n3(r13 − r33) has been reported for the dispersed material, which is 10 times higher than the corresponding grafted material, and a linear relationship between the poling intensity and the electrooptic coefficient has been observed for the two materials. [less ▲]

Detailed reference viewed: 6 (0 ULg)
See detailStroboscopic real-time holographic interferometry with photorefractive crystals applied to modal analysis
Georges, Marc ULg; Lemaire, Philippe ULg

in Gorecki, Christophe (Ed.) Optical Inspection and Micromeasurements II (1997, June)

A breadboard holographic interferometer that uses a photorefractive sillenite crystal under the anisotropic diffraction configuration is presented for application to quantitative vibration measurements ... [more ▼]

A breadboard holographic interferometer that uses a photorefractive sillenite crystal under the anisotropic diffraction configuration is presented for application to quantitative vibration measurements. After the hologram of the object at the rest is recorded, a stroboscope is used to observe the stable pattern of the vibrating object and phase-shifting is introduced for quantitative measurements. It is shown that this system can measure modal displacements of objects of typically 25*25 cm/sup 2/ with high accuracy ( lambda /40) by using a continuous YAG laser emitting 490 mW at 532 nm. The error sources are investigated and particularly a systematic error arising from the stroboscopic process can be calculated and eliminated [less ▲]

Detailed reference viewed: 6 (0 ULg)
See detailLes cristaux photoréfractifs de type sillénite comme support d'enregistrement en interférometrie holographique: originalités, potentialités et applications
Lemaire, Philippe ULg; Georges, Marc ULg

in Actes du 9ème séminaire SFO/HOLO3 : Les Applications Industrielles de l’Holographie et des Techniques Connexes (1996, November)

Detailed reference viewed: 12 (0 ULg)
See detailHolographic interferometry using photorefractive crystals: recent advances and applications
Georges, Marc ULg; Lemaire, Philippe ULg

in Gorecki, Christophe (Ed.) Optical Inspection and Micromeasurements (1996, June)

We present a real-time holographic interferometer using sillenite crystals for measurement of deformations of large diffusive objects. Two kind of optical heads have been investigated: a first system with ... [more ▼]

We present a real-time holographic interferometer using sillenite crystals for measurement of deformations of large diffusive objects. Two kind of optical heads have been investigated: a first system with a frontal crystal followed by a CCD camera with a short focal length objective, and a second system with imaging objective in front of the crystal, collecting light and imaging the object in its vicinity, the final image being observed with a second relay imagery. Both systems art compared with respect to their temporal behaviour and quality of interferograms. This interferometer is connected with quantitative phase-measurement systems. First, phase-shifting (PS) can be performed by translating a mirror in the reference beam, enabling acquisition of several interferograms subsequently processed leading to the object phase deformation. Nevertheless this requires stability of the object during the shifting process. Second, Fourier transform (FT) processing can be used on a single interferogram. This interferometer has been successively used in different applications: detection of defects in weakly disturbed structures using PS and monitoring of thermal deformation of an object with FT processing. [less ▲]

Detailed reference viewed: 4 (0 ULg)
Full Text
See detailHolographic interferometry using photorefractive crystals for quantitative phase measurement on large objects
Georges, Marc ULg; Lemaire, Philippe ULg

in Benton, Stephen (Ed.) Practical Holography X (1996, January)

We recently have presented a real-time holographic interferometer using sillenite crystals connected with phase-shifting for quantitative measurement of diffuse objects deformations. In our basic set-up ... [more ▼]

We recently have presented a real-time holographic interferometer using sillenite crystals connected with phase-shifting for quantitative measurement of diffuse objects deformations. In our basic set-up, the crystal, sandwiched between two polarizers, is set in front of the optical head and followed by a CCD camera with an imaging objective. With this system, for conventional objects and using 2.2 Watts of Ar3+ laser power @ 514 nm, interferograms can be observed on object fields of about 30 cm*20 cm (crystal size 1 cm*1 cm and 26 mm objective focal length). In this paper we present investigations to increase the observed field in the existing system and to be able to use lower power lasers. Since setting the object at larger distances should lead to an insufficient luminous level for hologram recording, we have proceeded by different ways. First, we use shorter focal length objectives, giving a larger field-of-view, and larger crystals have to be used in this case to avoid vignetting. Second, we use a large aperture frontal objective in order to collect more light and that images the object on the crystal, the final image being observed through relay imagery. [less ▲]

Detailed reference viewed: 13 (6 ULg)
See detailReal-time holographic interferometer with BSO crystal using phase-shifting for quantitative deformation measurements
Georges, Marc ULg; Lemaire, Philippe ULg

in Anderson, D.; Feinberg, J. (Eds.) Photorefractive Materials, Effects, and Devices (1995, June)

Detailed reference viewed: 4 (0 ULg)
See detailMéthodes de mesure de la phase
Lemaire, Philippe ULg; Georges, Marc ULg

Conference (1994, October)

Detailed reference viewed: 6 (1 ULg)
Peer Reviewed
See detailLocal measurement system for optical and electro-optic characterization and homogeneity analysis of photorefractive sillenite crystals
Lemaire, Philippe ULg; Georges, Marc ULg

in Roosen, G.; Agullo-Lopez, F.; Schirmer, O. (Eds.) Proceedings of Symposium C on Photorefractive Materials of the 1994 E-MRS Spring Conference (1994, May)

Detailed reference viewed: 1 (0 ULg)
Peer Reviewed
See detailCorrection Method of Secondary Reflection Effects in Measurement of Electrooptic Coefficient in Optically-Active Materials
Lemaire, Philippe ULg; Georges, Marc ULg

in Optics Communications (1992), 91(3-4), 260-266

The propagation of light in linearly birefringent and optically active media, such as Bi12SiO20 crystals (BSO), has been widely studied by several workers. Various measurement methods of the electro-optic ... [more ▼]

The propagation of light in linearly birefringent and optically active media, such as Bi12SiO20 crystals (BSO), has been widely studied by several workers. Various measurement methods of the electro-optic coefficient r41 have been described. One family of those methods consisting in measurement of the light polarization ellipticity after travelling through the crystal has been analysed. Due to the high reflectivity of such crystals, we show that the effect of the secondary reflections can not be neglected. We present the theoretical description and analysis of this effect for one of these methods and we propose a corrective algorithm. [less ▲]

Detailed reference viewed: 9 (0 ULg)
Peer Reviewed
See detailAbaissement du seuil d'hyperventilation par perfusion intraveineuse d'adrenaline lors d'un exercice triangulaire.
Scheen, André ULg; Lemaire, Philippe ULg

in Archives Internationales de Physiologie et de Biochimie (1983), 91(3), 187-96

Seven healthy male subjects underwent a treadmill incremental work test in control conditions and during an intravenous epinephrine infusion (10 micrograms/min). At all exercise intensities, epinephrine ... [more ▼]

Seven healthy male subjects underwent a treadmill incremental work test in control conditions and during an intravenous epinephrine infusion (10 micrograms/min). At all exercise intensities, epinephrine increased heart rate, ventilation, respiratory quotient and plasma lactate levels without significant changes in oxygen consumption. Under epinephrine infusion, the "anaerobic threshold", considered as the critical intensity at which ventilation began to increase non linearly with oxygen consumption, appeared at a lower intensity and for a higher plasma lactate level than in control conditions. We conclude that the hyperventilation threshold does not necessarily reflect a muscular hypoxia. It could be due to an effect of catecholamines on peripheral chemoreceptors, maybe by alpha-adrenergic vasoconstriction in the carotid bodies. [less ▲]

Detailed reference viewed: 47 (2 ULg)