References of "Fleury-Frenette, Karl"
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See detailPhotoconductivity and photoconversion at a photorefractive thin crystal plate
Frejlich, Jaime; de Oliveira, Ivan; de Araujo, William R. et al

in Optical Materials (2016), 55

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See detailDesign optimization of large-size format edge-lit light guide units
Hastanin, Juriy ULg; Lenaerts, Cedric ULg; Fleury-Frenette, Karl ULg

in Proceedings of SPIE; SPIE 2016 Photonics Europe (2016, April)

In this paper, we present an original method of dot-pattern generation dedicated to design optimization of large-size format ELBUs (Edge-Lit Light Guide Unit), where the number of dots greatly exceeds the ... [more ▼]

In this paper, we present an original method of dot-pattern generation dedicated to design optimization of large-size format ELBUs (Edge-Lit Light Guide Unit), where the number of dots greatly exceeds the maximum allowable number of optical objects supported by most common ray-tracing software. In the proposed method, in order to simplify the computational problem, an original optical system is replaced by an equivalent one. Accordingly, the original dot pattern is splitted into multiple small sections. Then, these sections are replaced by equivalent cells with continuous diffusing film. After that, we adjust the TIS (Total Integrated Scatter) two-dimensional distribution over the grid of equivalent cells, using an iterative optimization procedure. Finally, the obtained optimal TIS distribution is converted into the dot size distribution by applying an appropriate conversion rule. An original semi-empirical equation dedicated to rectangular large-size LGPs (Light Guide Plate) is proposed for the initial guess of the TIS distribution. It allows significantly reducing the time needed to dot pattern optimization. [less ▲]

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See detailCompact handheld low-cost biosensor platform for remote health monitoring
Hastanin, Juriy ULg; Lenaerts, Cedric ULg; Gailly, Patrick ULg et al

in Proceedings of SPIE; SPIE 2016 Photonics Europe (2016, April)

In this paper, we present an original concept of plasmonic-related instrumentation platform dedicated to diagnostic biosensing tests out of the laboratory. The developed instrumental platform includes ... [more ▼]

In this paper, we present an original concept of plasmonic-related instrumentation platform dedicated to diagnostic biosensing tests out of the laboratory. The developed instrumental platform includes both disposable one-use microfluidic affinity biochip and compact optical readout device for biochip monitoring involving mobile Internet devices for data processing and communication. The biochip includes both microfluidic and optical coupling structures formed into a single plastic slab. The microfluidic path of the biochip operates in passive capillary pumping mode. In the proof-of-concept prototype, we address specifically the sensing format involving Surface Plasmon Resonance phenomenon. The biochip is plugged in the readout device without the use of an index matching fluid. An essential advantage of the developed biochip is that its implementation involves conventional hot embossing and thin film deposition process, perfectly suited for mass production of low-cost microfluidic biochip for biochemical applications. [less ▲]

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See detailReal-time measurement of temperature variation during nanosecond pulsed laser induced contamination deposition
Kokkinos, Dimitrios ULg; Gailly, Patrick ULg; Georges, Marc ULg et al

in Applied Optics (2015), 54(36), 10579

In this paper a study of the heat generation during UV Laser Induced Contamination (LIC) and potentially resulting subsequent thermal damage is presented. This becomes increasingly interesting when optics ... [more ▼]

In this paper a study of the heat generation during UV Laser Induced Contamination (LIC) and potentially resulting subsequent thermal damage is presented. This becomes increasingly interesting when optics with delicate coatings are involved. During LIC radiation can interact with outgassing molecules both in the gas phase and at the surface, triggering chemical and photo-fixation reactions. This is a major hazard, in particular for laser units operating under vacuum conditions such as for space applications. The intense photon flux not only affects the contaminant deposition rate but also alters their chemical structure that can increase their absorption coefficient. Over cumulative irradiation shots these molecules formed deposits that increasingly absorb photons and produce heat as a by-product of de-excitation eventually leading to thermal damage. One could better asses the risk of the latter with the knowledge of temperature during the contamination process. For this purpose thermoreflectance technique is used here to estimate the temperature variation from pulse to pulse during contamination deposition through the analysis of a temperature-dependent surface reflectance signal. [less ▲]

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See detailDesign status of ASPIICS, an externally occulted coronagraph for PROBA-3
Renotte, Etienne ULg; Alia, A.; Bemporad, A. et al

in Proc. SPIE Volume 9604 Solar Physics and Space Weather Instrumentation VI (2015, September 21)

The “sonic region” of the Sun corona remains extremely difficult to observe with spatial resolution and sensitivity sufficient to understand the fine scale phenomena that govern the quiescent solar corona ... [more ▼]

The “sonic region” of the Sun corona remains extremely difficult to observe with spatial resolution and sensitivity sufficient to understand the fine scale phenomena that govern the quiescent solar corona, as well as phenomena that lead to coronal mass ejections (CMEs), which influence space weather. Improvement on this front requires eclipse-like conditions over long observation times. The space-borne coronagraphs flown so far provided a continuous coverage of the external parts of the corona but their over-occulting system did not permit to analyse the part of the white-light corona where the main coronal mass is concentrated. The proposed PROBA-3 Coronagraph System, also known as ASPIICS (Association of Spacecraft for Polarimetric and Imaging Investigation of the Corona of the Sun), with its novel design, will be the first space coronagraph to cover the range of radial distances between ~1.15 and 3 solar radii where the magnetic field plays a crucial role in the coronal dynamics, thus providing continuous observational conditions very close to those during a total solar eclipse. PROBA-3 is first a mission devoted to the in-orbit demonstration of precise formation flying techniques and technologies for future European missions, which will fly ASPIICS as primary payload. The instrument is distributed over two satellites flying in formation (approx. 150m apart) to form a giant coronagraph capable of producing a nearly perfect eclipse allowing observing the sun corona closer to the rim than ever before. The coronagraph instrument is developed by a large European consortium including about 20 partners from 7 countries under the auspices of the European Space Agency. This paper is reviewing the recent improvements and design updates of the ASPIICS instrument as it is stepping into the detailed design phase. [less ▲]

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See detailExperimental astrochemistry: from ground-based to space-borne laboratories (Foreword)
De Becker, Michaël ULg; Cottin, Hervé; Fleury-Frenette, Karl ULg et al

in Bulletin de la Société Royale des Sciences de Liège (2015, January), 84(4-6),

The investigation of the origin and evolution of molecules in space environments, either in interstellar or interplanetary conditions, constitutes a topic of high importance in modern space sciences. The ... [more ▼]

The investigation of the origin and evolution of molecules in space environments, either in interstellar or interplanetary conditions, constitutes a topic of high importance in modern space sciences. The presence of diversified and complex molecules motivates astrochemists to explore their formation mechanisms along with the physical conditions ruling these physico-chemical processes. Beside theoretical approaches aiming at simulating these processes, experimental techniques are nowadays frequently applied. Both laboratory and space experiment projects allow to reproduce to some extent the adequate conditions to understand some of these processes. The most recent results based on these techniques, and the prospects for future investigations, including the use of space platforms, were the scientific motivation of this workshop. These proceedings summarize a part of the content of this workshop, including abundant references to the relevant bibliography. [less ▲]

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See detailRoughness evolution of sol–gel optical coatings by ion beam sputtering
Gailly, Patrick ULg; Dubreuil, Olivier ULg; Fleury-Frenette, Karl ULg

in Nuclear Instruments and Methods in Physics Research B (2015), 365

The surface roughness evolution of two silica-based sol–gel materials under 650 eV argon ion beam sputtering has been investigated. The liquid sol–gel solutions were applied on silicon substrates using ... [more ▼]

The surface roughness evolution of two silica-based sol–gel materials under 650 eV argon ion beam sputtering has been investigated. The liquid sol–gel solutions were applied on silicon substrates using the dip coating technique and thermally cured to obtain thin solid films and their thicknesses were then controlled over the samples surface using spectroscopic ellipsometry. The surface roughness of the sol–gel films was measured using both interferometric profilometry and atomic force microscopy depending on the obtained sputtering depths. We observed a significant increase of the roughness according to the sputtering depth, faster in the case of sol–gel layers than with bulk fused silica. Interestingly, the sputtering rates of the sol–gel layers were found much higher than the rate obtained on bulk fused silica. The development of micron scale holes with relatively stable interstices is supposed to rule the surface roughness evolution. AFM measurements revealed a regular submicron scale lateral structure which nanometric amplitude is amplified within sputtering. [less ▲]

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See detailRoughness evolution of sol-gel optical coatings by ion beam sputtering
Gailly, Patrick ULg; Dubreuil, Olivier ULg; Fleury-Frenette, Karl ULg

Poster (2014, September 16)

The surface roughness evolution of two silica-based sol-gel materials under 650 eV argon ion beam sputtering has been investigated. The liquid sol-gel solutions had been applied on silicon substrates ... [more ▼]

The surface roughness evolution of two silica-based sol-gel materials under 650 eV argon ion beam sputtering has been investigated. The liquid sol-gel solutions had been applied on silicon substrates using the dip coating technique and then thermally cured to obtain solid thin films. Their thickness had then been controlled over the samples surface using spectroscopic ellipsometry. The surface roughness of the sol-gel films has been measured using both interferometric profilometry and atomic force microscopy at different sputtering depths. Roughness increases significantly faster with sputtering depth in sol-gel layers than on bulk fused silica. Interestingly, the sputtering rates of the sol-gel layers are also observed to be much higher that of bulk fused silica. The development of micron scale holes with relatively stable interstices rules the surface roughness evolution. AFM measurements revealed a regular submicron scale lateral structure which nanometric amplitude is amplified under sputtering. [less ▲]

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See detailMICROBIOMED: Planar optic chip manufacturing and read-out
Fleury-Frenette, Karl ULg; Hastanin, Juriy ULg; Lenaerts, Cedric ULg et al

Poster (2014, September 11)

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See detailIsolating auroral FUV emission lines using compact, broadband instrumentation
Molyneux, P.M.; Bannister, N.P.; Bunce, E.J. et al

in Planetary and Space Science (2014), 103

Images of auroral emissions at far ultraviolet (FUV, 122–200 nm) wavelengths are useful tools with which to study magnetospheric-ionospheric coupling, as the scattered sunlight background in this region ... [more ▼]

Images of auroral emissions at far ultraviolet (FUV, 122–200 nm) wavelengths are useful tools with which to study magnetospheric-ionospheric coupling, as the scattered sunlight background in this region is low, allowing both dayside and nightside auroras to be imaged simultaneously. The ratio of intensities between certain FUV emission lines or regions can be used to characterise the precipitating particles responsible for auroral emissions, and hence is a useful diagnostic of magnetospheric dynamics. Here, we describe how the addition of simple transmission filters to a compact broadband imager design allows far ultraviolet emission ratios to be deduced while also providing large-scale instantaneous images of the aurora. The low mass and volume of such an instrument would make it well-suited for both small satellite Earth-orbiting missions and larger outer planet missions from which it could be used to characterise the tenuous atmospheres observed at several moons, as well as studying the auroral emissions of the gas giants. We present a study to investigate the accuracy of a technique to allow emission line ratio retrieval, as applied to the OI 130.4 nm and 135.6 nm emissions at Ganymede. The ratio of these emissions provides information about the atmospheric composition, specifically the relative abundances of O and O2. Using modelled FUV spectra representative of Ganymede's atmosphere, based on observations by the Hubble Space Telescope (HST) Space Telescope Imaging Spectrograph (STIS), we find that the accuracy of the retrieved ratios is a function of the magnitude of the ratio, with the best measurements corresponding to a ratio of ∼1.3 . [less ▲]

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See detailNew Monolithic High Solar Rejection EUV Transmission Filter
Fleury-Frenette, Karl ULg; Renotte, Etienne ULg; Lenaerts, Cedric ULg et al

Conference (2014, August)

New Monolithic High Solar Rejection EUV Transmission Filter Fleury-Frenette, Karl; Renotte, Etienne; Lenaerts, C.; Rossi, Laurence; Jacques, Lionel; Halain, Jean-Philippe; Rochus, Pierre 40th COSPAR ... [more ▼]

New Monolithic High Solar Rejection EUV Transmission Filter Fleury-Frenette, Karl; Renotte, Etienne; Lenaerts, C.; Rossi, Laurence; Jacques, Lionel; Halain, Jean-Philippe; Rochus, Pierre 40th COSPAR Scientific Assembly. Held 2-10 August 2014, in Moscow, Russia, Abstract D2.3-22-14. A new high solar rejection transmission filter for the extreme UV has been developed for the Solar Orbiter Extreme Ultraviolet Imager (EUI). To provide enhanced resilience to high thermal load, a monolithic architecture approach has been taken in order to limit the thermal contact resistance between the filtering sub-micron thin film, its supporting mesh, and holding frame. Some aspects of the manufacturing process involving thin film deposition and photolithography will be presented along with optical performance and space environmental test results. New avenues for improving the thermo-optical properties of the filter will also be discussed. [less ▲]

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See detailSpectral splitting planar solar concentrator : Design and Experimental testing Preliminary results
Blain, Pascal ULg; Michel, Céline ULg; Clermont, Lionel ULg et al

in Proceedings of SPIE (2014, May 15), 9140

We present a new concept in solar concentrator: spectral splitting. It implies reflective, refractive and diffractive elements that allow two spectrally differentiated beams to reach different and/or ... [more ▼]

We present a new concept in solar concentrator: spectral splitting. It implies reflective, refractive and diffractive elements that allow two spectrally differentiated beams to reach different and/or unmatched lattice solar cells. Those cells efficiencies are then enhanced. The aimed geometrical concentration factor is 5× and the theoretical optical efficiency of that concentrator concept reaches 82%. [less ▲]

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See detailDevelopment of a microfluidic lab-on-a-chip platform for breast cancer early diagnosis
Fleury-Frenette, Karl ULg; Puettmann, Christiane; Stein, Christoph et al

Poster (2014, March 10)

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See detailTransmitive spectral SPR droplet biosensing: principle, sensor design and experimental demonstration
Hastanin, Juriy ULg; Lenaerts, Cedric ULg; Fleury-Frenette, Karl ULg et al

in Plasmonics (2013)

Surface Plasmons Resonance (SPR) architectures based on grating coupler/disperser combination is an attractive alternative for spectral-based biochemical sensing. In this paper, we investigate ... [more ▼]

Surface Plasmons Resonance (SPR) architectures based on grating coupler/disperser combination is an attractive alternative for spectral-based biochemical sensing. In this paper, we investigate theoretically and experimentally a new concept where the plasmon coupling occurs through a thin film grating and sensing occurs via the first evanescent diffraction order in transmitive mode. The surface plasmon wave excitation induces a peak in the wavelength as well as in the angular spectra of the detected first transmitted diffraction order. Accordingly, a change in SPR spectrum of the detected diffraction order can be used to quantify the amount of the target molecules immobilized on the sensor surface and therefore, the concentration of these molecules in the analyte solution. The developed sensor architecture is dedicated to droplet biochemical sensing and appears to be especially suitable for biosensor integration and miniaturization. The presented sensor concept is perfectly suited for mass production of low-cost and reproducible SPR sensor chip for biochemical analysis. The implemented setup gives access to multichannel biosensing with the potential for efficient internal referencing, essential to achieve sufficiently high reproducibility and accuracy of the measurements. [less ▲]

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See detailA Thermal Detector
Fleury-Frenette, Karl ULg; Habraken, Serge ULg; Renotte, Yvon ULg et al

Patent (2013)

A first object of the invention is a radiation detector comprising an energy absorber (203), for absorbing incident radiation (RAD) and thus undergoing a temperature increase; and optical readout means ... [more ▼]

A first object of the invention is a radiation detector comprising an energy absorber (203), for absorbing incident radiation (RAD) and thus undergoing a temperature increase; and optical readout means, for detecting said temperature increase; wherein said optical readout means comprises input coupling means (202) for coupling a light beam (2011) to said energy absorber (203) by exciting surface plasmons resonance, a surface plasmons resonance condition being dependent on the energy absorber (203) temperature, and wherein said energy absorber (203) is separated from said input coupling means (202) by a dielectric layer (2032). A second object of the invention is a micromechanical sensor comprising: a micromechanical oscillator and optical readout means (202) for detecting a displacement of said micromechanical oscillator; wherein said optical readout means comprise input coupling means (202) for coupling a light beam (2011) to a conductive surface (2031) by exciting surface plasmons resonance, a surface plasmons resonance condition being dependent on the displacement of said micromechanical oscillator. [less ▲]

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