Dissertations / Theses on the topic 'Revêtement optique'
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Marchand, Julien. "Revêtements de qualité optique à base de solutions sol-gel aqueuses et d’un procédé de dépôt par pulvérisation en solution." Electronic Thesis or Diss., Tours, 2021. http://www.theses.fr/2021TOUR4002.
Differents techniques are available to produce optical coatings. Sol-gel process combined to liquid deposition is particulary interesting as it is possible to coat huge scale components with easily accessible and industrial processes (dip-coating, spin-coating). In the field of optical coatings for power lasers such as Laser MégaJoule at CEA, sol-gel process has been industrialy implemented for many years to produce antireflective coatings which present a maximum transmission at the wavelenghts of interest with an adequate laser flux resistance in accordance with hig density of light energy. However, the usual solvent for these coatings is ethanol, which is easily flammable. This risk has to be taken into account for large scale deposition.This thesis work aimed to reduce or even suppress this hazard by using water instead of alcoholic solvents. The main challenge is double : synthesis of stable sol-gel colloids solution in aqueous media (for some years at least) in one hand, and on the other hand the development of an innovative process to realise optical coatings with spray-coating.This modification of media and coating technique significantly affect thin layer formation and numerous parameters had been studied to achieve coatings with optical quality (homogeneity of thickness) on large surfaces (200 x 200 mm²).Among these parameters, the drying time has changed from few seconds to several minutes with the use of water, water's wetting which is less efficient than alcoholic solvent's wetting, solid concentration in solution, spraying conditions (flow rate, aeraulic flow, nozzle-substrate distance...), coating conditions (temperature, hygrometry).In this study, we pointed that controlling drying conditions of the deposited film is essential to ensure the optical quality of coatings on a large scale. First results in modelling the drying of these films are described.Controlling optical quality of coatings realised by spray seems possible under some conditions
Le, Bouffant Jean. "Étude de l'excentricité d'une fibre optique dans son revêtement époxy-acrylate et réalisation d'un dispositif de mesure en temps réel." Paris 11, 1986. http://www.theses.fr/1986PA112270.
Berthod, Loïc. "La photolithographie cylindrique sur revêtement sol-gel photogravable." Thesis, Lyon, 2017. http://www.theses.fr/2017LYSES009/document.
The aim of this thesis is to analyze the photolithography tools used to print diffraction gratings and to identify those that are sufficiently flexible to be adapted to unconventional substrates such as cylinders or tubes. The photolithography tools developed have also been adjusted in order to write directly a diffraction grating in a functional layer of TiO2, supplied by the sol-gel pathway. This thesis is a prospective study because the periodicity or the pattern of the registered diffracting structures has not been defined for a specific application. Two photolithography tools have been successfully adapted to cylindrical substrates. They will be presented here and will be accompanied with a perspective for a specific application. Finally, the last chapter is distinct from the previous ones because it does not concern the development of a photolithography tool but on the chemical transformation of TiO2 (dielectric) into TiN (metal), it nevertheless remains in the continuity of its thesis because this transformation is adapted to all types of substrates
Moreau, Julien. "Nouvelle métrologie optique pour l'amélioration des performances de l'antenne gravitationnelle VIRGO." Paris 6, 2005. http://www.theses.fr/2005PA066337.
Perrot, Jean-Luc. "Explorations optiques multimodales et multiéchelles non invasives appliquées au revêtement cutanéomuqueux , étendues à l'appareil oculaire antérieur." Thesis, Lyon, 2017. http://www.theses.fr/2017LYSES010/document.
After a brief introduction to the history of non-invasive dermatological imaging, this work is divided into 3 parts. 1) Presentation of a project for the development of a low-cost miniaturized optical coherence tomograph to allow dissemination of this technique to dermatologists practicing outside hospitals. This is an ANR project: DOCT-VCSEL Portable Optical Coherence Tomography with MEMS-VCSEL swept-sources for skin analysis ANR 2015 / Societal Challenge "Life, Health and Welfare" Axis 13 “Technologies for Health" 2) Presentation of a project whose goal is the identification of cancer skin lesions by means of a new high definition OCT developed by the company DAMAE, resulting from the Higher Institute of Optics of Palaiseau. It is a device that will initially be reserved for centers of excellence in dermatological imaging. 3) Presentation of 52 publications related to skin imaging, in which I participated, and referenced in the international databases as of December 31, 2016. This work covers all modern dermatological non-invasive imaging and addresses Subjects that had never been studied in this way. Notably the mucous membranes and the anterior ocular apparatus but also the identification by confocal microscopy of the surgical margins or the association confocal microscopy Raman spectrometry
Sokolov, Dmitry. "Contribution au développement de la projection thermique à très faible pression." Phd thesis, Université de Technologie de Belfort-Montbeliard, 2009. http://tel.archives-ouvertes.fr/tel-00603187.
Tessier, Florent. "Etude expérimentale de l'implosion de bulles de cavitation optique au voisinage de parois souples : application à la tenue d'un revêtement élastomérique à l'érosion de cavitation." Aix-Marseille 1, 2003. http://www.theses.fr/2003AIX11043.
Anooshehpour, Farid. "Optical emission spectroscopy as a process-monitoring tool in PECVD of amorphous carbon coatings." Master's thesis, Université Laval, 2016. http://hdl.handle.net/20.500.11794/27142.
The production of amorphous carbon coatings or as commonly known as diamond like carbon (DLC) coatings, using the plasma enhanced chemical vapor deposition (PECVD) method is studied through optical emission spectroscopy (OES) as a plasma diagnostic technique and the partial least square regression (PLSR) statistical method. The objective is to establish a model to predict DLC properties independent of reactor-related parameters, in order to be used in any other similar deposition process. Therefore the model correlates the deposited coating properties to plasma parameters derived from OES. The OES derived data carries a variety of information about plasma characteristics. The relative spectral line intensities of CH and atomic H to specific Ar lines were employed as a probe of their concentrations according to actinometry method. The full width at half maximum of atomic H was also employed. This method can be used as a probe of gas temperature via Doppler broadening effect. The DLC coatings were characterized using profilometry for thickness and stress measurements and Auger electron spectroscopy (AES) for structural analysis. There were two series of PLSR analysis carried out: The first analysis studies the correlation between process parameters and plasma characteristics, as derived by OES, for a better understanding of the plasma deposition process. The second analysis shows how the OES can be used for prediction of coating properties and for process monitoring. According to the results, the OES data (especially the parameters that are related to the concentration of atomic hydrogen and CH species) are able to represent some parts of process parameters (plasma power, mode and pressure) in a statistical model that is designed for predicting DLC coating properties. In other words, this means that this plasma diagnostic technique can be employed for in-situ monitoring of growing DLC coating properties, instead of using process parameters, which are related to the deposition reactor and may vary from one system to another. The perspective of using the OES data and the PLSR analysis in designing and monitoring a structurally gradient DLC coating is also discussed.
Pavlov, Mikhail. "Application des dispositifs de diagnostic optique multi-spectraux dans les procédés de fabrication additive : fusion sélective par laser et projection laser coaxiale." Ecole nationale d'ingénieurs (Saint-Etienne), 2011. http://www.theses.fr/2011ENISE007.
The manuscript contains four chapters including a general introduction presenting the optical diagnostics, followed by a chapter on the application of the selective laser melting and two chapters on a process of laser cladding. Chapter 1 is an introduction to optical diagnostics tools designed to measure the temperature of an object without physical contact. The importance of the choice of the spectral band as a function of temperature is also highlighted. Chapter 2 describes the study the process of selective laser melting. The first part concerns the description of the selective laser melting machine used. On this machine various optical elements have been added for visualization of powder layering process and the molten pool coaxially with the laser beam. Chapter 3 describes the study of laser cladding of titanium carbide and steel powders. This chapter begins with a bibliographical part. Thermal imaging camera (3-5 micron band) and a multi-wavelength pyrometer (1-1. 27 microns) were applied to monitor the zone of laser action. The effects of various operating parameters on the temperature profiles (true and brightness) were examined in detail. The fourth chapter describes the laser cladding on a substrate TA6V with powder of the same composition. A thermal imaging camera (3-5 microns) was applied to obtain the temperature distributions in the laser action zone
Hidden, Guillaume. "Développement d'un nouveau revêtement de contrôle thermique pour satellites d'orbite géostationnaire : étude de l'influence de nanoparticules conductrices sur les propriétés thermo-optiques et électriques du composite." Toulouse 3, 2005. http://www.theses.fr/2005TOU30031.
Charlot, Aude. "Élaboration et caractérisation de revêtements submicroniques obtenus par électrodéposition de nanoparticules de silice." Thesis, Montpellier, Ecole nationale supérieure de chimie, 2014. http://www.theses.fr/2014ENCM0003/document.
The development of a submicron coating was carried out by electrophoretic deposition (EPD)of silica nanoparticles. This approach allows controlling the thickness of the deposits which is a parameter to adjust to develop a selective absorber coating dedicated to a photothermal sensor. The composition of the desired coating is a co-deposition of silica and carbon. For the understanding and the control of EPD deposition mechanisms, silica deposit is first studied. Two systems were investigated: silica deposited on a silicon wafer or platinum substrate, respectively noted SiO2/Si and SiO2/Pt. A commercial colloidal suspension, Ludox® HS-40, is used to realize stable diluted sols of monodispersed silica nanoparticles (12 nm diameter), negatively charged. Anodic EPD is performed in aqueous medium from this sol.The applied potential, the initial concentration of nanoparticles and the deposition time are investigated. When the applied potential is too high, the water electrolysis phenomenon occurs. More particularly, the platinum-based system is limited by this phenomenon, from a potential of +2 V. The high conductivity of this substrate promotes gassing phenomenon. This subsequent bubbling degrades the cohesion of the coating. However, an applied potential lower than the electrolysis potential gives some good deposition conditions. Similar phenomena were also observed with SiO2/Si system. However, the semiconductor properties of the silicon wafer enable to apply higher potential (up to +40 V) by reducing the phenomenon of electrolysis. Optimizations of the deposition conditions on these two systems have yielded experimental deposition conditions consistent with the objective, namely: a potential of +1 V to SiO2/Pt system and of +3 and +30 V for SiO2/Si system, a concentration between 1 and 10 %mass, and a deposition time of 1 hour.Under optimum conditions defined above, the physicochemical properties of the initial suspension are modified by adding a co-solvent (EtOH), a salt (Na2SO4) or a polymer (PAA or PVA) in order to study the influence of the dispersing medium, the conductivity of the suspension or the zeta potential of the nanoparticles on the thickness of the deposits. These additions have increased the thicknesses of coatings, especially for SiO2(EtOH)/Pt system and systems based on PAA. The addition of some carbon compounds (PVA or PAA) in the suspension was also studied to obtain after calcinations (500 °C) a coating with interesting characteristics for the intended application. Coating obtained with SiO2(PAA)/Pt system exhibit a significant optical selectivity. However, the value of the alpha/epsilon ratio remains below 7, which is lower than the values obtained for the same type of system with conventional sol-gel processes
El-Yadouni, Abderrazzak. "Étude par optique guidée des propriétés optiques linéaires et non linéaires de couches minces de semi-conducteurs à grand gap." Metz, 2002. http://docnum.univ-lorraine.fr/public/UPV-M/Theses/2002/El_Yadouni.Abderrazak.SMZ0228.pdf.
Benabed, Mohamed Salim. "Élaboration de revêtements à base de titane en milieu igné." Paris 6, 1986. http://www.theses.fr/1986PA066373.
Zhu, Lin. "Etude de la projection plasma sous très faible pression - torches et procédé de dépôt." Phd thesis, Université de Technologie de Belfort-Montbeliard, 2011. http://tel.archives-ouvertes.fr/tel-00703247.
Fan, Xiujuan. "Elaboration et caractérisation des revêtements base Titane fabriqués par projection thermique sous très basse pression." Thesis, Bourgogne Franche-Comté, 2019. http://www.theses.fr/2019UBFCA006.
Thermal spraying processes allow the manufacturing of high versatility coatings (metals, ceramics, polymers or other composites), relatively thick (from few microns to several centimeters) with a high deposition rate. However, drawbacks exist in particular the impossibility to use non-congruent fusion precursors such as nitrides (TiN for example) limiting their industrial application (aeronautics, energy, biomedical, etc.). This kind of coating is mainly obtained by thin-film processes. Very low-pressure plasma spraying (VLPPS) opens a potential to overcome this problem to obtain nitride/oxide/carbide coatings with high deposition rates unlike thin-film processes. For this purpose, the liquid phase usually generated by the particles injection into the thermal source of the spray jet can rise to the vapor state due to the conditions of the very low pressure. As a result, dense coatings with a lamellar, condensed vapors or a mix of both microstructures are manufactured. Furthermore, a reactive gas (nitrogen, oxygen, etc.) can be injected with the vapors to form oxide, nitride materials.This work consisted in studying the fabrication of oxides and nitrides ceramic coatings by reactive - very low-pressure plasma spraying (R-VLPPS) from a pure powder of titanium. Firstly, the diagnostic of the plasma jet under very low pressure (plasma and reactive gases, precursor) was carried out with the aim of correlating the presence of the detected species with the properties of the coatings. Titanium nitrides and oxides coatings were manufactured by R-VLPPS. The spraying parameters of the deposits (spraying distance, reactive gas injection method) were analyzed. The composition and the mechanical characteristics of the coatings are determined. Moreover, the plasma jet has also been tested as post-treatment process to improve the amount of nitrided or oxidized phases. Finally, the manufacturing mechanism of the coatings was developed from the experimental results
Klotz, Geoffroy. "Revêtements d’optique de transformation en hyperfréquences." Thesis, Aix-Marseille, 2020. http://www.theses.fr/2020AIXM0126.
The present thesis work relates to transformational optics and its applications. Invisibility cloaks and carpets, as well as mimetic coatings, are studied using simulations with the commercial software COMSOL Multiphysics in the micro-wave domain. First, these simulations help in the understanding of the phenomena at stake and allow us to evaluate how challenging it would be to develop experimental devices. Based on objective criteria, we consider multiple systems and discuss their efficiency and feasibility. The realization of transformation optics coatings is a difficult challenge, so we suggest a multilayer design for the coatings. As dielectric permittivity and magnetic permeability required in the OT coatings are unusual among natural materials, we worked on resonant metamaterials composed of a lattice of small conducting structures. The physical origin of the phenomenon is investigated, as the homogenization technics allowing computation of effective homogeneous parameters. Finally, we consider the realization of invisibility cloaks using frequency dispersive metamaterials and developed a design allowing broadband operations
Compoint, François. "Développement de revêtements optiques hybrides organiques-inorganiques pour limiter l'endommagement laser." Thesis, Tours, 2015. http://www.theses.fr/2015TOUR4030/document.
The optical devices (lents, mirrors, portholes…) that are set on the chains of the Laser Megajoule (LMJ) may be damaged by the high energy laser beam especially around the UV wavelength of 351 nm. The damages are micronics craters on the rear of the optics that grows exponentially after each laser shots. The study aim at developing some optical thin coatings on the rear of the optical substrates to prevent the growth of the damage by amortizing the laser shockwave, self-healing the craters that has appeared, or repairing the laser hole after the damage occurs. The thin coatings have been prepared by a sol-gel method by using silica precursor and a polydimethylsiloxane (PDMS) elastomer. The two species reacted together to get a hybrid organic-inorganic Ormosil (organically modified silica) material, by creating a silica network linked to the PDMS species with covalent and hydrogens bounds. The thin layers are obtained from the sol-gel solution by using a dip and spin coating method
Merati, Abdenacer. "Comportement à la corrosion en milieux salins des revêtements monocouches de titane et d'aluminium et des multicouches alternées Ti/Al, élaborées par technique PVD multiarcs." Lyon, INSA, 1994. http://www.theses.fr/1994ISAL0025.
Titanium and aluminium monolayers and alternate Ti/Al PVD multiarc coatings, deposited on 35CD4 steel, are charaterized. The monolayer thicknesses influence (5 15 or 30 micrometres), the multilayer strata distribution (5-6 strata) and the substrate shape (smooth or threaded) were studied. Charaterizations were carried on the nature and microstructure of layers by using optical microscopy and SEM, and on the corrosion behaviour in aqueous saline media (recording potent ial vs time, voltamperometric plots, electrochemical impedance, salt spray). To complete the study of coated threaded samples, characterization was also carried out controled Ti tests. Elaborated coatings are always microporous. The adherence is excellent. Better uniformity and density are noticed for the titani layers, than for the aluminium's ones, and multilayer coatings are more protectiv than the monolayers. The best behaviour is observed when the titanium is in contact with steel and aluminium on the top (in contact with corrosive media), is suitable to decrease the risk of galvanic corrosion. The tightening effect is to calk the deposit surfaces, without modifying too much the electrochemical teristics of samples
Duchêne, Marie. "Développement d'une nouvelle technologie pour la réalisation de filtres interférentiels de type "allumette"." Phd thesis, Université Paul Cézanne - Aix-Marseille III, 2009. http://tel.archives-ouvertes.fr/tel-00471569.
Hun, Catherine. "Exploitation de la texture d'images de speckle pour caractériser, de façon globale, l'état de surface des chaussées à l'échelle de la microtexture." Phd thesis, Université Louis Pasteur - Strasbourg I, 2002. http://tel.archives-ouvertes.fr/tel-00003899.
Gautier, Julien. "Etude et élaboration de revêtements multicouches pour l'optique extrême UV dans la gamme spectrale 30-50 NM." Paris 11, 2005. http://www.theses.fr/2005PA112299.
The development of new multilayer interferential coatings is justified by the request of solar astrophysics and the development of new EUV sources (High harmonics generation, laser X, synchrotron radiation). We have studied and developed various multilayer systems with optimized optical properties (reflectivity and/or band-width) and good temporal and thermal stability for wavelengths ranging from 30 nm to 50 nm. Multilayer for the harmonic selection were optimized and used for the realization of an EUV interferometer. A significant increase in the reflectivity of multilayer in the spectral range from 30 nm to 40 nm was obtained by the addition of a third material in the stack. A comparative study of theoretical and experimental reflectivity curves versus the wavelength was made. The differences observed have been explained by using the analysis of the physical properties of various materials in thin layer. We have also shown that the use of these three component multilayers allows the development of stack for specific requests (broadband mirrors, dual band mirrors). For wavelengths ranging from 35 nm to 50 nm we have developed Sc/Si multilayers. Multilayers with high reflectivity and good temporal stability have been achieved. We have improved the stability of these stacks by using interfacial barrier layers
Ventura, Céline. "Etude des propriétés radiatives des milieux granulaires : traitement des données par analyse en composantes principales, résolution des problèmes inverses, percolation." Aix-Marseille 1, 1999. http://www.theses.fr/1999AIX11013.
Viard, Jocelyn. "Caractérisations de couches minces d'oxynitrures de silicium élaborées par PECVD." Montpellier 2, 1996. http://www.theses.fr/1996MON20034.
Vitupier, Yann. "Etude et mise au point de substrats de miroirs ultra légers et hyperstables revêtus d'un dépôt polissable pour application aux télescopes spatiaux." Montpellier 2, 2003. http://www.theses.fr/2003MON20168.
Tului, Mario. "Propriétés optiques d'oxydes et de borures obtenus par projection plasma sous différentes pressions." Lille 1, 2003. https://ori-nuxeo.univ-lille1.fr/nuxeo/site/esupversions/ffb1542c-075d-4fca-993b-e28e0fdf3565.
Burcklen, Catherine. "Microscope X dans la fenêtre de l’eau : conception, miroirs à revêtements multicouches et métrologie associée." Thesis, Université Paris-Saclay (ComUE), 2017. http://www.theses.fr/2017SACLO002/document.
The observation of biological samples at a nanometer scale is currently a major topic for biology. In particular, X-ray microscopy in the water-window (between Oxygen and Carbon K-alpha edges, corresponding to a wavelength between 2.4 and 4.4 nm) is off remarkable interest since it enables the visualization of biological samples with a natural high absorption contrast and a high resolution thanks to the short working wavelength. Several such x-ray microscopes have already been developed and showed resolutions down to 12 nm. In this context, we develop at Laboratoire Charles Fabry a full field, near normal incidence mirror based X-ray microscope. The optical design of the microscope was studied and optimized in a first place. It is based on a Schwarzschild objective, with a rather long working distance so that the installation of the sample will be facilitated. The mirrors are to be coated with very short period multilayer coatings containing chromium and scandium. Several multilayer systems with sub-nanometer thick layers ere studied in order to obtain the highest reflectance possible near normal incidence at a wavelength near 3.14 nm. Those systems were Cr/Sc, Cr/B4C/Sc, CrN/Sc and CrN/B4C/Sc. A peak reflectance of 23% has been measured for CrN/B4C/Sc at an incidence angle lower than 5°
Avice, Jérémy. "Etudes des propriétés physico-chimiques de revêtements sol-gel par spectroscopie, optoacoustique et endommagement laser." Thesis, Le Mans, 2018. http://www.theses.fr/2018LEMA1028.
Within the framework of the simulation project, the Atomic Energy Commission (CEA) aims to reproduce the pressure and temperature conditions of a thermonuclear fusion with the Megajoule laser (LMJ). Some of the optical components of the LMJ, in particular some focusing lenses, are coated with an antireflective (AR) layer made by a sol-gel process. These films are composed of silica nanoparticles 10 nm in diameter with 55% porosity. To increase the mechanical strength of these layers, the films are exposed to water and ammonia vapors during a post-process. This post-treatment creates covalent bonds between the silica nanoparticles and thus strengthens the colloidal film. In order to give all the qualities of an optical coating, besides the key optical properties, we have set ourselves the objective of understanding the mechanical stability of these nanomaterials. In particular, we wanted, in the context of this thesis, to have a better understanding of the ammonia hardening process and for that we undertook a complete study of the physical and chemical parameters that govern the elasticity of this assembly of nanoparticles. In a second step, we highlighted the appearance of surface cracking causing optical diffusion and a decrease in mechanical reinforcement during the post-process. In order to minimize or even eliminate these surface cracks, we performed a parametric study to identify the elements responsible for this cracking
Le, Guevel Xavier. "Elaboration de sols de silice colloïdale en milieu aqueux : fonctionnalisation, propriétés optiques et de détection chimique des revêtements correspondants." Tours, 2006. http://www.theses.fr/2006TOUR4005.
The aim of this work was to study surface reactivity of silice nanoparticles through physical and chemical properties of sols and coatings. Appliatons are numerous and they are illustrated in this work by optical coating preparation for laser components and chemical gas sensor development for nitroaromatics detection
Coussot, Cahuzac Aline. "Etude de nouveaux monomères et oligomères fluorés photoréticulables : application aux revêtements étanches à l'eau pour fibres optiques télécommunication." Montpellier 2, 1994. http://www.theses.fr/1994MON20098.
Vedovotto, Nathalie. "Les couches minces de carbone amorphe hydrogéné : durcissement et traitement antireflet à 10,6μm des optiques de germanium." Lyon 1, 1988. http://www.theses.fr/1988LYO10033.
Gautier, Julien. "ÉTUDE ET ÉLABORATION DE REVÊTEMENTS MULTICOUCHES POUR L'OPTIQUE EXTRÊME UV DANS LA GAMME SPECTRALE 30-50 NM." Phd thesis, Université Paris Sud - Paris XI, 2005. http://tel.archives-ouvertes.fr/tel-00011659.
Marchet, Nicolas. "Synthèse et stabilisation de suspensions colloïdales d'oxydes en milieu organique : application à la préparation de matériaux hybrides organiques-inorganiques pour des revêtements à très haute tenue au flux laser." Thesis, Tours, 2008. http://www.theses.fr/2008TOUR4002/document.
Multilayer coatings are widely used in optic and particular in the field of high power laser on the components of laser chains. The development of a highly reflective coating with a laser damage resistance requires the fine-tuning of a multilayer stack constituted by a succession alternated by materials with low and high refractive index. In order to limit the number of layers in the stack, refractive indexes must be optimized. To do it, an original approach consists in synthesizing new organic-inorganic hybrid materials satisfying the criteria of laser damage resistance and optimized refractive index. These hybrid materials are constituted by nanoparticles of metal oxides synthesized by sol-gel process and dispersed in an organic polymer with high laser damage threshold. Nevertheless, this composite system requires returning both compatible phases between them by chemical grafting of alcoxysilanes or carboxylic acids. We showed that it was so possible to disperse in a homogeneous way these functionalized nanoparticles in non-polar, aprotic solvent containing solubilized organic polymers, to obtain time-stable nanocomposite solutions. From these organic-inorganic hybrid solutions, thin films with optical quality and high laser damage threshold were obtained. These promising results have permitted to realize highly reflective stacks, constituted by 7 pairs with optical properties in agreement with the theoretical models and high laser damage threshold
Naudin, Guillaume. "Revêtements antireflets multifonctionnels par voie sol-gel : application au domaine de l'automobile." Electronic Thesis or Diss., Paris 6, 2017. https://accesdistant.sorbonne-universite.fr/login?url=https://theses-intra.sorbonne-universite.fr/2017PA066613.pdf.
A multifunctional coating for the automotive industry was elaborated by depositing sol-gel thin films onto glass substrates. Broadband antireflective coatings were synthetized by tuning the optical properties of each deposited layer in order to promote destructive interferences. Different strategies based on a bilayer system and a trilayer system were used to add additional functionalities to the coating. A specific approach was developed to observe fog formation both at the macroscopic scale and at the microscopic scale and therefore to choose the best antifogging coating. These observations were discussed with a modelling method which allows us to compare the macroscopic opacification and the microdroplets populations. Moreover, mechanical tests were performed
Beigbeder, Joana. "Etudes des propriétés physiques de nanocomposites à matrice polysiloxane : application au développement d'un revêtement de contrôle thermique froid et antistatique." Toulouse 3, 2009. http://thesesups.ups-tlse.fr/702/.
Solar reflectors are new cold (low solar absorptivity, high thermal emissivity) thermal control coatings for satellites slightly sensitive to low earth orbit (LEO) environment. The aim of our work is their adaptation to geostationary (GEO) environment. These reflectors are composed of a reflective layer and a transparent highly electrically resistive polysiloxane coating. To evacuate electrical charges induced by GEO environment, carbon nanotubes (CNT) and metal oxides nanoparticles (zinc oxide, indium tin oxide ITO) were added to the resin and their effect on thermo-optical, electrical and electrostatic discharge (ESD) properties studied. A small proportion of CNT into polymer leads to a better electrical conductivity for the composite but also to an important solar absorptivity. Adding ITO nanoparticles to the polymer permits to increase the thermal emissivity and so to lower the thickness of coatings. ITO composites display good electrostatic discharge with low ITO concentrations. Zinc oxide particles do not permit to improve the electrical properties of composites
Lehtihet, Moncef. "Réalisation de revêtements composites par voie liquide pour la gestion des infrarouges solaires." Thesis, Bordeaux, 2020. http://www.theses.fr/2020BORD0226.
This PhD project focuses on the designing, realization and characterization of coatings deposited by liquid means, for the management of infrared solar light, regarding applications towards building efficency and solar energy harvesting. We aim to produce composite thin films, composed of polymeric matrix in which solid inclusions are added. An engineering of these inclusions permits one to reach the desired functionality. A complete modelling of composite thin film on a substrate is proposed. An optimal transport regime of light is found where the absorption is enhanced by the addition of scattering. A bench for thin film production is realized and experimental methods of characerization of the various physical phenomena occuring during material deposition is studied. A theoretical and experimental study of the influence of the optical properties of thin film on its thermal performances is proposed. Polymeric thin films containing gold nanoparticles are used as proof-of-concept of the enhanced heat generation by light scattering. Also, PEDOT:PSS/Silicon thin films are realized to control independently the absorption and scattering in films and explore such optimal regime in the near-infrared part of the spectrum
Naudin, Guillaume. "Revêtements antireflets multifonctionnels par voie sol-gel : application au domaine de l'automobile." Thesis, Paris 6, 2017. http://www.theses.fr/2017PA066613/document.
A multifunctional coating for the automotive industry was elaborated by depositing sol-gel thin films onto glass substrates. Broadband antireflective coatings were synthetized by tuning the optical properties of each deposited layer in order to promote destructive interferences. Different strategies based on a bilayer system and a trilayer system were used to add additional functionalities to the coating. A specific approach was developed to observe fog formation both at the macroscopic scale and at the microscopic scale and therefore to choose the best antifogging coating. These observations were discussed with a modelling method which allows us to compare the macroscopic opacification and the microdroplets populations. Moreover, mechanical tests were performed
Marthe, Jimmy. "Élaboration par projection plasma d'un revêtement bicouche d'alumine réfléchissant et diffusant. Contribution à la compréhension des phénomènes interaction rayonnement/matière." Thesis, Université de Lorraine, 2013. http://www.theses.fr/2013LORR0258/document.
This study deals with the manufacturing of reflecting and scattering coatings by plasma spraying process. By the selection of operating parameters and the control of the coatings microstructure, the first part of this work presents the elaboration of a micro/nanostructured bilayer material in alumina with a reflectance up to 90 % in the near UV-Visible range of wavelength. The feasibility of larger pieces (0.25m2) is demonstrated and the different characterizations for inserting the material in the Laser MegaJoule are performed. In a second part, from characterizations of the microstructure (by SEM, Hg Porosimetry, USAXS) and the chemical composition (DRX, X fluorescence), the improvement of the reflectance in the near-UV thanks to the nanostructured layer is explained, on the one hand, by the less absorbing crystallographic phase and, on the other hand, by the smaller and numerous pores. Moreover, the characterization of the radiation properties by the Radiation Transfer Equation inversion brings new elements for understanding the phenomena during radiation/porous media interaction and to determine the spatial repartition of the scattering radiation. The aim of the last part is to set up the different tools which are necessary to compute simulations of plasma-sprayed coatings optical behavior. From the microstructure analysis, a tridimensional numerical representation of each layer is suggested. The resolution of Maxwell equations is performed by FDTD (Finite Difference Time Domain) method. The model is validated and some first simulations are realized
Bourassin-Bouchet, Charles. "Optiques pour les impulsions attosecondes." Phd thesis, Université Paris Sud - Paris XI, 2011. http://tel.archives-ouvertes.fr/tel-00657772.
Chapel, Anthony. "Etude du comportement photochimique de revêtements composites polymère/particules luminescentes pour applications à l'éclairage éco-énergétique à base de LEDS. Impact du vieillissement sur les performances optiques." Thesis, Clermont-Ferrand 2, 2016. http://www.theses.fr/2016CLF22672/document.
Phosphor-converted LEDs are emerging as an eco-friendly solution for the next generation lighting. Despite lifetimes claimed over 50 000h, a loss of the optical properties was noticed. This work focuses on the influence of photodegradation of the materials on the optical properties of the polymer/phosphor composite that is used to encapsulate the semiconductor chip. Luminescent composites were made from a polymer matrix (EVA or PMMA) and an inorganic phosphor: Y3BO6 :15% Eu3+. The evolution of physical, chemical and optical properties of these composites was investigated under irradiation in accelerated conditions (λ>300 nm) and in the use conditions of UV LED (λ=365 nm). The phosphor showed no pro-degrading effect on the photooxidation of the polymer. A loss of the optical properties of the composite was observed and ascribed to the photodegradation of the polymer in the case of the EVA matrix. The evolution of photometric parameters of the emitted light by the luminescent composite during photoaging can be attributed to the accumulation of photoproducts in films. However, for PMMA/phosphor composites, the chemical structure and optical properties of such composites are kept for accelerated photoaging time up to 4000h
Dieudonné, Xavier. "Etude d'empilements multicouches colloidaux préparés par voie sol-gel : propriétés optiques et mécaniques." Thesis, Tours, 2011. http://www.theses.fr/2011TOUR4022/document.
Main optical deposition processes, physical vapor deposition or sol-gel, exhibit difficulties of achieving thick coatings (>1 µm) and to build multilayer stacks (dielectric mirrors, polarizers). For these reasons, we have studied the conditions to enable a significative increase of deposited sol-gel films thickness. Three main parameters have been evidenced enabling the control of the stacking ability : single layer deposited thickness, chemical interactions beetween nanoparticles and coating drying time. We have shown that these parameters depend on the sol composition and on deposition conditions (process) and that the microstructure of single material stacking is influenced. Optical and mechanical properties of sol-gel films have been studied and optimized regarding these different material and process parameters. For this reason, optical and mechanical characterization techniques have been specifically developed and can now be used for fragile and thin film characterization. In controlling all these parameters, it is now possible to prepare multilayer colloidal stack with high thicknesses enabling the fabrication of high-performance mirrors and polarizers
Sorre, Benoît. "Role of membrane curvature in intracellular trafficking : 3 case studies." Paris 7, 2010. http://www.theses.fr/2010PA077021.
Intracellular trafficking thus consists in a permanent exchange of membrane structures transporting lipids and proteins from a compartment of the cell to another. T. Membrane is not only the passive envelope of transport intermediates and the physico-chemical properties of the membrane have to be taken into account. In particular, a growing number of experimental evidence shows that membrane curvature might play an important part in the regulation of intracellular processes. Indeed, transport intermediates are very curved objects (R< 50nm) compared to the membrane from which they are formed. This problem being difficult to study inside the cell, we have used an in vitro approach consisting in pulling membrane nanotubes out of Giant Unilamellar Vesicles. It allows setting the tube radius in the 10-100nm range while monitoring its composition thanks to fluorescence and force measurements. We have used this approach to show that membrane curvature is able to induce lipid sorting and under which conditions. We have also been interested in which way the curvature-dependent enzymatic activity of ArfGAPl affects the spatial localization of its substrate (Arfl) in a membrane configuration where a highly curved membrane part is connected to a fiat membrane reservoir Finally, we have been interested to the membrane deformation capabilities of amphiphysin1, a protein belonging to the BAR domain protein family
Chasserio, Nadège. "Corrélations entre la composition et le structure de particules d’oxydes mixtes de métaux de transition et leurs propriétés optiques et thermoradiatives." Toulouse 3, 2006. http://www.theses.fr/2006TOU30191.
The aim of this study is to integrate oxide powders in aeronautical coatings to limit thermal contrasts between the aircraft and its environment in the infrared range. The optical characteristics (complex refractive index and hemispherical directional reflectivity) and radiative one (emissivity) have been measured. The studied oxides are ferrites and manganites with spinel structure. A study of the chemical composition of CuxNiyMn3-x-yO4 has allowed to optimize the optical properties (n up to 3,8 for λ =3µm). The roles of the cationic distribution and of the proportion of Cu+ cations have been shown. The radiative behaviour of the coatings charged by these oxides has been simulated. The theory of the radiative transfer has been used to consider the multiple diffusion phenomena. Simulations have shown the strong influence of the binder on the limitation of the performances. The obtained coatings have permitted to reduce the apparent temperature of 30°C (for a real temperature of 100°C)
Morgado, Nazario. "Réalisation d'un anti-reflet bispectral sur substrat de ZnS hémisphérique en technique P. E. C. V. D. : performances et tenue à la pluvio-érosion." Lyon 1, 1997. http://www.theses.fr/1997LYO10185.
Di, Giacomo Laurie. "PACVD/PVD de multicouches sélectives pour la conversion thermodynamique de l'énergie solaire." Thesis, Perpignan, 2017. http://www.theses.fr/2017PERP0042.
In concentrated solar power (CSP) plants, solar flux is concentrated on receivers to heat a transfer fluid up to 600°C. In order to improve their optical properties, these receivers can be covered by multilayered spectrally selective coatings. This work is devoted to designing and developing innovative spectrally selective structures showing strong absorption (low reflectivity) in the visible and near infrared range and low emissivity (high reflectivity) in the infrared range. We developed such stacks associating a refractory metal with high IR reflectivity and a ceramic which improves absorption in the visible range and thermal stability. The coatings were synthesized by plasma techniques, combining PACVD and PVD. Pre-industrial process feasibility, its development and optimization through the design of an innovative reactor, layer deposition and characterization, their combination in efficient optically selective stacks and the study of their aging have been achieved
Rebellato, Jennifer. "Miroirs interférentiels efficaces dans l’extrême ultraviolet pour la physique solaire." Thesis, université Paris-Saclay, 2020. http://www.theses.fr/2020UPASP059.
X-rays and extreme ultraviolet (EUV) light are emitted by excited particles in the solar corona because of its intense activity and extreme temperatures. Recent solar space telescopes in this spectral region showed increased performances thanks to the interference multilayer mirrors on-board. This thesis aims at enhancing such optical coatings, starting with an evaluation of EUV optical constant values available in the literature to select materials more accurately, and to refine optical simulations. This work allows us to introduce better simulations for an accurate calibration of the EUV Full Sun Imager aboard Solar Orbiter. Also, we show that mastering thin films deposition and optical and structural characterization techniques allowed us to develop new Al/Sc-based multilayer coatings reaching record reflectivity values above 40 nm wavelength, which is still a quite unexplored region. These thesis results pave the way for a new and highly efficient generation of solar observation instruments in the EUV, but they also have a remarkable impact in a wider scientific community in need for ever more efficient optical instrumentation in the EUV such as synchrotrons, EUV lithography, X-ray diagnostics, or even X-ray microscopy
Bruckner, Jean-Baptiste. "Réseaux de diffraction et métamatériaux photoniques pour le contrôle de la lumière dans le visible et l’infrarouge." Thesis, Aix-Marseille, 2014. http://www.theses.fr/2014AIXM4319.
Thanks to recent advances in nanofabrication, the realization of photonic structures was possible, allowing the control of light as an information vector or for energy harvesting. This PhD thesis adresses the studies carried out in collaboration with Thales Optronics on two demonstrators for the ANR NPOEM research project, whose objective is to fabricate photonic structures on flexible substrates by nanoimprint technology. The first demonstrator consists of an antireflective coating using resonance phenomena within biperiodic diffraction gratings. Conical structures with flat, rough or patterned tops were modeled by FDTD and RCWA, carried out in collaboration with the CEA Liten LTM and then characterized at the IM2NP institute. The antireflective performances obtained are remarkable (reflection coefficient lower than 2 % at normal incidence) and extend over a wide spectral range from the visible to the infrared region. The second demonstrator presents a low-pass type filtering function at optical and infrared frequencies. A study of several resonant structures such as metamaterials (metallic crosses, metal-dielectric-metal stack, metallic cones and perforated plates) showed singular propagation phenomena related to small dimensions (modes, surface waves and proximity coupling) and led to the completion of a large surface, flexible filter demonstrating the desired properties. The photonic components made during this thesis have applications in the stealth and thermal solar domains
Charles, Cédric. "Etude théorique et expérimentale des relations architecture - propriétés optiques de films minces d'oxyde de tungstène pulvérisés par GAD." Phd thesis, Université de Franche-Comté, 2013. http://tel.archives-ouvertes.fr/tel-01063023.
Diveki, Zsolt. "Generation and Application of Attosecond Pulses." Phd thesis, Université Paris Sud - Paris XI, 2011. http://tel.archives-ouvertes.fr/tel-00722473.
Zhang, Yu. "Fabrication, structural and spectroscopic studies of wide bandgap semiconducting nanoparticles of ZnO for application as white light emitting diodes." Thesis, Lyon, 2020. http://www.theses.fr/2020LYSEI046.
The present thesis studies ZnO nanoparticles embedded in a mesospheric polyacrylic acid (PAA) matrix synthesized via a hydrolysis protocol. The mesospheric ZnO/PAA hybrid structure was previously proved efficient in emitting visible light in a broad range, which results from the deep-level intrinsic defects in ZnO nanocrystals. To further tune the photoluminescence (PL) spectrum and improve the PL quantum yield (PL QY) of the material, metal-doped ZnO and silica-coated ZnO/PAA are fabricated independently. For ZnO doped with metallic elements, the nature, concentration, size and valence of the dopant are found to affect the formation of the mesospheres and consequently the PL and PL QY. Ions larger than Zn2+ with a higher valence tend to induce larger mesospheres and unembedded ZnO nanoparticles. Doping generally leads to the quenching of PL, but the PL spectrum can still be tuned in a wide range (between 2.46 eV and 2.17 eV) without degrading the PL QY by doping small ions at a low doping concentration (0.1 %). For silica-coated ZnO/PAA, an optimal coating correlatively depends on the amount of TEOS and ammonia in the coating process. The amount of TEOS does not affect the crystal structure of ZnO or the PL spectrum of the material, but high concentration of ammonia can degrade the PAA mesospheres and thicken the silica shell. A thin layer of silica that does not absorb too much excitation light but completely covers the mesospheres proves to be the most efficient, with a drastic PL QY improvement of six times. Regarding the application, the materials suffer from thermal quenching at temperatures high up to 100°C, at which white light emitting diodes (WLEDs) generally operates. However, silica-coated ZnO/PAA induces higher emission intensity at room temperature to make up for the thermal quenching
Jaouen, Kévin. "Backside absorbing layer microscopy : a new tool for the investigation of 2D materials." Thesis, Université Paris-Saclay (ComUE), 2019. http://www.theses.fr/2019SACLS296/document.
Optical microscopy based on anti-reflective coatings is a simple yet powerful characterization tool which notably allowed the first observation of graphene in 2004. Since then, the field of two-dimensional (2D) materials has developed rapidly both at the fundamental and applied levels. These ultrathin materials present inhomogeneities (edges, grain boundaries, multilayers, etc.) which strongly impact their physical and chemical properties. Thus their local characterization is essential. This thesis focuses on a recent enhanced-contrast optical microscopy technique, named BALM, based on ultrathin (2-5 nm) and strongly light-absorbing (metallic) anti-reflective layers. The goal is notably to evaluate the benefits of this technique for the study of 2D materials and their chemical reactivity. The various levers to improve 2D materials observation were investigated and optimized for two model materials: graphene oxide and MoS₂ monolayers. The investigation of molecular layer deposition dynamic notably showed the extreme sensitivity of BALM for such measurements and the significant contribution of multilayers anti-reflective coatings to enhance contrast during the observation of 2D materials. One of the main assets of BALM comes from its combination to other techniques. We particularly considered the coupling between optical measurements and electrochemistry for which the anti-reflective layer serves as working electrode. We investigated optically the dynamic of electrochemical reduction of Graphene Oxide (GO), the electrografting of organic layers by diazonium salts reduction on GO and its reduced form (rGO), as well as the intercalation of metallic ions within GO sheets. By combining versatility and high-contrast, BALM is established as a promising tool for the study of 2D materials, especially for the local and in situ characterization of their chemical and electrochemical reactivity