Rozprawy doktorskie na temat „Photons – Localisation”
Utwórz poprawne odniesienie w stylach APA, MLA, Chicago, Harvard i wielu innych
Sprawdź 22 najlepszych rozpraw doktorskich naukowych na temat „Photons – Localisation”.
Przycisk „Dodaj do bibliografii” jest dostępny obok każdej pracy w bibliografii. Użyj go – a my automatycznie utworzymy odniesienie bibliograficzne do wybranej pracy w stylu cytowania, którego potrzebujesz: APA, MLA, Harvard, Chicago, Vancouver itp.
Możesz również pobrać pełny tekst publikacji naukowej w formacie „.pdf” i przeczytać adnotację do pracy online, jeśli odpowiednie parametry są dostępne w metadanych.
Przeglądaj rozprawy doktorskie z różnych dziedzin i twórz odpowiednie bibliografie.
Mazal, Daniel Alejandro. "Radiothérapie stéréotaxique par petits faisceaux de rayons x de haute énergie : développement des moyens techniques et dosimétriques". Toulouse 3, 1990. http://www.theses.fr/1990TOU30069.
Juennard, Nicolas Jauffret Claude Xerri Bernard. "Détection et localisation de particules de très hautes énergies en acoustique sous-marine". [S. l.] : [s.n], 2007. http://tel.archives-ouvertes.fr/tel-00252061/fr.
Pichette, Julien. "Imagerie de fluorescence et intrinsèque de milieux diffusants par temps d’arrivée des premiers photons". Thèse, Université de Sherbrooke, 2014. http://savoirs.usherbrooke.ca/handle/11143/387.
Cajgfinger, Thomas. "Étude théorique et expérimentale du suivi de particules uniques en conditions extrêmes : imagerie aux photons uniques". Phd thesis, Université Claude Bernard - Lyon I, 2012. http://tel.archives-ouvertes.fr/tel-00770124.
Chef, Samuel. "Contribution à l'analyse de signaux acquis par émission de photons dynamique pour l'étude de circuits à très haute intégration". Thesis, Dijon, 2014. http://www.theses.fr/2014DIJOS032/document.
Scaling progresses has the benefit of making chips always more powerful. On the other hand, when there is a failure, the analysis of such advanced devices has became more sensitive. The defect localization step of this process is the critical one. Indeed, the aim is to find transistors which dimensions range in several nanometers on a device which surface is several square centimeters.Optical techniques like dynamical photon emission, also named Time Resolved Imaging (TRI), have proved to fit in such context. The later is based on the acquisition and exploitation of photons emitted by a switching CMOS structure. Due to its physical bacground, this tool has a limited invasive effect and can be used to analyze defect generating faults during a dynamical stimulation of the device. The complexity of the chips manufactured in advanced technologies has brought out some physical and technical limitations which can jeopardize analysis performed with this tool. To be more specific, signal over noise ratio can be quite low, so as the spatial resolution compared to the studied structures. In addition, complex circuits require long test sequences, generating huge quantities of photons to analyse. As a conclusion, all of these phenomenon forbid a simple manual procedure if ones expect to extract the emission signature of the defect in such data.The work reported in this thesis aims to develop new approaches of processing at the post-acquisition level, in order to solve or workaround the various aforementioned issues. It will enable the analyst to formulate an even better and more precise diagnosis.The task consists in extracting and synthesizing the information available in large amount of noisy signals. With that superpose in mind, two main approaches have been studied and developed. The first one establish a mapping of one parameter the electrical signals varying through time and space inside the acquisition area. It is based on a mixture of signal processing tools for 2D 1D signals. The second approaches uses data mining. More precisely, it combines clustering to statistical analyses of the resulting classes in order to find an emission event which is unexpected or having unusual properties, suggesting a candidate for failure. These two processes are complementary as they bring different information to the analyst
Crosnier, de Bellaistre Cécile. "Conductance et étalement d'une onde quantique dans un guide unidimensionnel : effet d'une force". Thesis, Université Paris-Saclay (ComUE), 2017. http://www.theses.fr/2017SACLO009/document.
A wave can be exponentially localized in a disordered medium, due to interference effects. This Anderson localization phenomenon leads to a cancellation of the conductance of a quantum fluid in 1D. However, theoretical works pointed out that an electric field may reduce or cancel this localization. We study here the effect of a force on the localization of a 1D quantum matter wave. Since both Anderson localization of an expanding wave packet and the effect of disorder on the transport between two reservoirs have been studied in ultracold atom experiments, we focus on two systems, namely the diffusion, or the transmission, of a particle.In order to calculate the transmission, we generalize a transfer matrix formalism to the presence of a, possibly inhomogeneous, force. The case of a speckle disorder as used in ultracold atom experiments is dealt with using two other analytical approaches. Our main is result is that the force can be entirely taken into account by renormalising the length with a local mean free path of the particle. For white-noise disorder, the force leads to a weaker, algebraic localization, whereas full delocalization appears for a correlated disorder. We then focus on the diffusion of a particle, using a numerical approach. A transition of delocalization of the particle for strong forces is shed into light through a power law increase of its position, whose exponent increases with the force. Moreover, we show that localization is systematically destroyed in a correlated disorder
Real, Elgueda Bastián Maximiliano. "Transport and driven-dissipative localization in exciton-polariton lattices". Electronic Thesis or Diss., Université de Lille (2022-....), 2022. http://www.theses.fr/2022ULILR025.
The simulation of lattice Hamiltonians in photonic platforms has been enlightening in the understanding of novel transport and localization properties in the context of solid-state physics. In particular, exciton-polaritons provide a versatile system to investigate these properties in lattices with intriguing band structures in the presence of gain and loss, and particle interactions. Polaritons are hybrid light-matter quasiparticles arising from the strong coupling between photons and excitons in semiconductor microcavities, whose properties can be directly accessed in photoluminescence experiments. In this thesis, we firstly study the features of strained honeycomb lattices made of coupled polariton resonators having high photonic content. In a critically strained lattice, we evidence both a semi-Dirac transport and an anisotropic localization of photons. Secondly, we show that a judicious driving in lattices of lossy resonators allows the appearance of novel localized modes. Using polariton lattices driven resonantly with several optical beams, we demonstrate the localization of light in at-will geometries down to a single site. Finally, we take advantage of the polarization-dependent polariton interaction to demonstrate an optical Zeeman-like effect in a single micropillar. In combination with optical spin-orbit coupling inherent to semiconductor microstructures, the interaction-induced Zeeman effect results in emission of vortex beams with a well-defined chirality. This thesis brings to light the power of polariton platforms to study lattice Hamiltonians with unprecedented properties and it also provides a first step towards the fully-optical generation of topological phases in lattices
Juennard, Nicolas. "Détection et localisation de particules de très hautes énergies en acoustique sous-marine". Phd thesis, Université du Sud Toulon Var, 2007. http://tel.archives-ouvertes.fr/tel-00295026.
Dans un second temps, plusieurs méthodes de détection sont étudiées, de la plus classique (étude du rapport de vraisemblance} à des méthodes plus récente (filtrage adapté, classification, etc.). La comparaison expérimentale en situation semi-réelle de celles-ci aboutit au choix de la méthode de détection suivante : le FASE (Filtrage Adapté Stochastique Etendu). Enfin, la position et la direction du neutrino sont estimés par un algorithme dérivé de Gauss-Newton, Cet estimateur se base sur la modélisation du déplacement du front d'onde acoustique et sur les informations temporelles de détection fournies par les hydrophones du télescope. De nombreuses configurations sont testées et les performances du système sont évaluées. Une structure d'hydrophone est proposée et une simulation dite « globale » finalisent cette thèse. Dans celle-ci, les étapes de détection et d'estimation sont basées sur les résultats obtenus précédemment. Les bruits de mer sont des bruits réels issus de campagnes de mesure et les résultats obtenus valident les travaux de cette thèse.
Raynaud, Christophe. "Spectroscopie d'absorption et d'émission des excitons dans les nanotubes de carbone". Thesis, Sorbonne Paris Cité, 2018. http://www.theses.fr/2018USPCC199/document.
The optical properties of carbon nanotubes are ideally described by the physicsof a one-dimensional object, giving rise in particular to the emergence of excitons todescribe the optical transitions of these objects. The optical experiments (emission,absorption) carried out on these objects at ambient temperature and on ensemblesconfirm the theoretical predictions based on the physics of 1D objects. But atcryogenic temperature and at the single emitter scale, the optical properties observedexperimentally are systematically different from those of a 1D object. One can citethe emergence of properties such as photon antibunching, which largely contributed tothe intensification of research on these objects for applications in quantum photonics.These properties are attributed to the localization of excitons along the nanotube axisin local potential wells (traps) created randomly by the interaction of nanotubes withtheir environment. The optical properties are then close to those of 0D objects, andare strongly modulated by the environment. The mechanisms and the origin of thelocalization and the physical knowledge of these traps are still very limited. This workshows on the one hand the development of an absorption setup on individual objectand the characterization of its sensitivity, and on the other hand the statistical studyof the emission of nanotubes at cryogenic temperature in a micro-photoluminescencesetup. The results obtained in the later setup by a super-resolution technique coupledwith hyper-spectral imaging show the characteristic quantities of potential wellswithin individual nanotubes. An experimental excitation-resolved photoluminescencesetup implemented during this work also showed a modification of the fundamentalexcitonic state by the environment, with the emergence of a spatial and spectraldiscretization of the delocalized ground state in a multitude of localized states
Zang, Xiaorun. "Lumière lente dans les guides à cristaux photoniques pour l'interaction renforcée avec la matière". Thesis, Bordeaux, 2015. http://www.theses.fr/2015BORD0172/document.
In this thesis, we firstly investigated the striking influence of random disorder on light transport near band edges in one dimensional photonic crystal wave guides, i.e. light localization. Near-field measurements, statistical simulations and theoretical model revealed the existence of a lower bound for the spatial extent of localized modes. We also showed that the disorder level and the spatial extent of individual localized mode is linked by the photon effective mass rather than the generally considered group velocity. Secondly, hybrid cold atoms and photonic crystal wave guides system have been recognized as a promising paradigm for engineering large light-matter interaction at single atoms and photons level. In this thesis, we studied the basic physics, i.e. light transport in periodic nanophotonic wave guides coupled to two-level atoms. Our developed general semi-analytical expression can quickly characterize the coupling between cold atoms and guided photons. Aim to overcome the significant technical challenges existed for developing hybrid atom-photonic systems, we designed a nanophotonic waveguide, which supports a slow guided Bloch mode with large evanescent tail in free space for cold atoms trapping (release the limitation imposed by Casmir Polder force and technical challenge of nanoscale manipulation of cold atoms). To match precisely the slow light region of the guided mode to the atomic transition line, we carefully engineered the photonic band and the dispersion curve (i.e.flatness) of the guided mode so that the interaction strength is robust against unpredictable fabrication imperfection
Houdart, Florent. "La sous-unité régulatrice de la phosphodiestérase photo-activable : interaction avec des protéines à domaine SH3 et localisation synaptique dans les photorécepteurs". Poitiers, 2005. http://www.theses.fr/2005POIT2319.
In photoreceptors, phosphodiesterase 6 (PDE6) is regulated, due to the shuttling of its regulatory subunit (P). Recent studies have indicated that P can interact with SH3 domains and that it can alter MAPK signalling. Therefore, we sought to identify SH3-containing proteins that might interact with P in rat photoreceptors. A yeast two-hybrid and GST “Pull-Down” assay allowed us to identify two proteins involved in endocytosis (amphiphysin and PACSIN) and three proteins involved in receptor tyrosine kinase signalling (Src, GRB2 and P85-PI3K), as putative partners of P. Three of these proteins (amphiphysin, PACSIN and P85-PI3K) were clearly expressed in photoreceptors. However, only PACSIN was found to interact in vivo with P in inner segments and synaptic pedicles of photoreceptors and that P concentration in synaptic pedicles increases in response to light. A developmental study allowed us to detect P expression in the retina of newborn rats (P0). At the early stages of retinogenesis (P0 to P5), P immunodetection was confined to basal pedicles of photoreceptors. A result suggesting that P might play a role in the establishment of photoreceptor synapses. To investigate the possible roles of P in photoreceptor differentiation, retinas of P rod -/- mice were examined. Electron microscopic observations revealed a deficit of well-defined rod triads in the outer plexiform layer of P rod-/- mice. Together, the data suggest that P-pacsin interaction may contribute to specific characteristics of the endocytic mechanism at the ribbon synapse of photoreceptors and that P is required for optimal differentiation of rod synapses
Faggiani, Rémi. "Resonant nanophotonics : structural slow light and slow plasmons". Thesis, Bordeaux, 2016. http://www.theses.fr/2016BORD0396/document.
Enhancing light-matter interactions at micro and nanoscales is one of the spearheads of nanophotonics. Indeed, the control of the field distribution due to the resonant interaction of nanostructures with electromagnetic waves has prompted the development of numerous optical components for many applications in telecommunication, spectroscopy or sensing. A promising approach lies in the control of light speed in nanostructures. Light slowdown, obtained by wave interferences in periodic structures or subwavelength confinement in plasmonic waveguides, is associated to pulse compressions and large field enhancements,which are envisioned as key processes for the miniaturization of optical devices and the enhancement of light-matter interactions.The thesis studies both fundamental aspects and possible applications related to slow light in photonic and plasmonic nanostructures. In particular, we study the impact of periodic system sizes on the group velocity reduction and propose a novelfamily of resonators that implement slow light on very small spatial scales. We then investigate the role of fabrication disorder in slow periodic waveguides on light localization and demonstrate how modal properties influence the confinement of localized modes. Also we propose a new hollow-core photonic crystal waveguide that provides efficient and remote couplings between the waveguide and atoms thatare trapped away from it. Finally we demonstrate the important role played by slow plasmons on the emission of quantum emitters placed in nanogap plasmonic antennas and explain how large radiation efficiency can be achieved by overcoming quenching in the metal. Additionally, one part of the thesis is devoted to thederivation of a novel modal method to accurately describe the dynamics of plasmonic resonators under short pulse illumination
Guillet, Thierry. "Nature du désordre et propriétés optiques des excitons dans les fils quantiques semi-conducteurs : de la boîte au fil". Paris 6, 2002. https://tel.archives-ouvertes.fr/tel-00006929.
Lepers, Maxence. "Dynamique d'atomes dans des potentiels optiques : du chaos quantique au chaos quasi-classique". Phd thesis, Université des Sciences et Technologie de Lille - Lille I, 2009. http://tel.archives-ouvertes.fr/tel-00391054.
Comme tout phénomène d'interférence, la localisation dynamique est affectée par l'émission spontanée. Dans cette thèse, nous proposons une méthode basée sur la spectroscopie Raman, pour limiter l'impact de l'émission spontanée. Nous menons une étude analytique complète de la dynamique, en très bon accord avec nos simulations numériques.
Du fait de sa périodicité temporelle, le rotateur pulsé présente aussi des résonances quantiques, qui sont l'analogue de l'effet Talbot optique. En décrivant ces résonances dans l'espace des positions, nous en donnons une image simple et intuitive, basée sur des notions classiques comme la force.
Les condensats de Bose-Einstein ont ouvert la voie à l'obtention de phénomènes quantiques nouveaux. La non-linéarité de leur équation d'évolution permet notamment l'observation du chaos quasi-classique. Nous proposons ici une méthode pour le détecter, basée sur la mesure de la position moyenne du condensat. Cette méthode, dont la validité est confirmée par les exposants de Lyapunov du système, permet de distinguer sans équivoque les trajectoires chaotiques et régulières.
Mojzisova, Halina. "Facteurs structuraux et physicochimiques déterminant la localisation cellulaire de photosensibilisateurs et leur capacité à photo-perméabiliser des membranes : étude sur des membranes modèles, des protéines plasmatiques et des cellules en culture". Paris 6, 2007. http://www.theses.fr/2007PA066479.
Lepers, Maxence. "Dynamique d'atomes dans des potentiels optiques : du chaos quantique au chaos quasi-classique". Electronic Thesis or Diss., Lille 1, 2009. http://www.theses.fr/2009LIL10012.
This thesis contains theoretical results about chaos in quantum systems. ln its first part, we study the dynamics of the quantum kicked rotor. This system, which is paradigmatic of quantum chaos, exhibits dynamical localization, a decay of diffusion in momentum space. The latter is a purely quantum phenomenon, as it is based on destructive interferences. As aIl interference effects, dynamical localization is affected by spontaneous emission. ln this manuscript, we propose a method to decrease the effect of spontaneous emission, by using Raman spectroscopy. We perform a full analytical study in very good agreement with our numerical simulations. As a consequence ofits temporal periodicity, the kicked rotor also exhibits quantum resonances, the analogy of the optical Talbot effect. By describing them in position space, we provide a simple and intuitive image of the resonances, based on classical notions like force. Bose-Einstein has enabled the study ofunprecedented quantum phenomena. ln particular, the nonlinearity of their evolution equation has made possible the observation of quasi-classical chaos. Here, we propose a method to detect chaos, by measuring the averaged position of the condensate. This method enables us to clearly distinguish chaotic and regular trajectories. Its validity is confirmed by the calculation of the system Lyapunov exponents
Sienkiewicz, Magdalena. "Méthodologie de localisation des défauts soft dans les circuits intégrés mixtes et analogiques par stimulation par faisceau laser : analyse de résultats des techniques dynamiques paramétriques". Thesis, Bordeaux 1, 2010. http://www.theses.fr/2010BOR14028/document.
This thesis deals with Soft failure localization in the analog and mixed mode Integrated Circuits (ICs) by means of Dynamic Laser Stimulation techniques (DLS). The results obtained using these techniques are very complex to analyze in the case of analog and mixed ICs. In this work we develop a methodology which facilitates the analysis of the laser mapping. This methodology consists on combining the experimental results (laser mapping) with the electrical simulations of laser stimulation impact on the device. The influence of photoelectric and thermal phenomena on the IC (transistor level) has been modeled and simulated. The methodology has been validated primarily on test structures before being used on complex Freescale ICs existing in commerce
Bachelier, Guillaume. "Propriétés optiques de nano-structures métalliques et semi-conductrices". Phd thesis, Université Paul Sabatier - Toulouse III, 2004. http://tel.archives-ouvertes.fr/tel-00008229.
Arias, Olivares David. "Relation Among Localization, Delocalization and Physicochemical Properties. From Electron Density Databases to Magnetic Properties Effects of the acceptor unit in dyes with acceptor–bridge–donor architecture on the electron photo-injection mechanism and aggregation in DSSCs The role of Cr, Mo and W in the electronic delocalization and the metal–ring interaction in metallocene complexes". Thesis, Sorbonne université, 2019. http://www.theses.fr/2019SORUS015.
The first property here analysed and related with electronic localization/delocalization is the aromaticity. Aromaticity is an important concept introduced by Kekulé; since then, theoreticians and experimentalist have tried to understand it in different groups of molecules analogues to benzene. The importance of this concept and how the aromaticity is affected by the chemical environment is important to understand and link some physicochemical properties. i.e., reactivity, stability, magnetic response. The physicochemical properties of interest are the electronic structure, the nature of bonds and organometallic interactions(differentiation between metallocenes and metallabencenes). Furthermore, the magnetic response and the study of building blocks as possible candidates to make nano-wires or new low-dimension magnetic materials. Finally, we try to understand the interaction and the errors involved in some properties theoretically computed like, the isotropic coupling between metals through aromatic (or organic) units that have become important benchmark molecules to study magnetic properties in inorganic as well as metal-organic systems [...]
Ruess, Frank Joachim Physics Faculty of Science UNSW. "Atomically controlled device fabrication using STM". Awarded by:University of New South Wales. Physics, 2006. http://handle.unsw.edu.au/1959.4/24855.
Jiménez, Banzo Ana María. "New insights in photodynamic theraphy: production, diffusion and reactivity of singlet oxygen in biological systems". Doctoral thesis, Universitat Ramon Llull, 2008. http://hdl.handle.net/10803/9310.
La incertesa respecte a la producció de 1O2 en un orgànul determinat es pot eliminar mitjançant l'ús de fotosensibilitzadors modificats genèticament, ja que aquets poden ésser expressats selectivament. Amb aquesta finalitat, s'avaluen les propietats fotosensibilitzants de mutants de proteïna fluorescent verd (GFP). Algunes de les GFPs estudiades sensibilitzen la formació del 1O2 malgrat amb baixa eficiència. Els resultats obtinguts es comparen amb els del cromòfor de la GFP i mostren que l'estructura proteínica, a sobre de modular les propietats fotofísiques del cromòfor, també el protegeix de la desactivació col·lisional.
Finalment, s'estudien les propietats d'absorció bifotónica del 2,7,12,17-tetrafenilporficé i del seu complex de pal·ladi (II). L'eficiència de formació del 1O2 per part dels dos compostos, desprès de l'absorció simultània de dos fotons, es aproximadament 100 vegades superior a la dels seus anàlegs porfirínics, amb seccions d'absorció bifotòniques δ ~ 25 GM. Les excel·lents propietats d'aquestos compostos s'expliquen mitjançant arguments qualitatius i s'analitzen les seves perspectives de cara al seu ús en teràpia fotodinámica.
Se ha estudiado la cinética de fotosensibilización de 1O2 en células eucariotas en suspensión, usando un espectrómetro de última generación con resolución temporal por debajo del microsegundo. Los estudios revelan que la cinética del 1O2 depende de su lugar de formación. Por una parte, la producción de 1O2 es más lenta en los lisosomas que en el núcleo. Por otra parte, el 1O2 es capaz de escapar de las células cuando es fotosensibilizado en el núcleo, mientras que queda confinado en el interior si se fotosensibiliza en los lisosomas. A pesar de que el tiempo de vida del 1O2 se encuentra en los microsegundos, la desactivación principal viene dada por interacciones con las biomoléculas características de cada orgánulo.
La incertidumbre respecto a la producción de 1O2 en un orgánulo determinado puede ser eliminada mediante el uso de fotosensibilizadores modificados genéticamente ya que pueden ser expresados selectivamente. Con este fin, se evalúan las propiedades fotosensibilizantes de mutantes de proteína fluorescente verde (GFP). Algunas de las GFPs estudiadas sensibilizan la formación de 1O2 aunque con baja eficiencia. Los resultados obtenidos se comparan con los del cromóforo de la GFP y muestran que la estructura proteínica, además de modular las propiedades fotofísicas del cromofóro, también lo protege de la desactivación colisional.
Finalmente, se estudian las propiedades de absorción bifotónica del 2,7,12,17-tetrafenilporficeno y de su complejo de paladio (II). La eficacia de formación de 1O2 de ambos compuestos, tras la absorción simultánea de dos fotones, es aproximadamente 100 veces superior a la de sus análogos porfirínicos, con secciones de absorción bifotónica δ ~ 25 GM. Las excelentes propiedades de estos compuestos se explican mediante argumentos cualitativos y se analizan sus perspectivas de cara a su uso en terapia fotodinámica.
The kinetics of singlet oxygen (1O2) photosensitisation in human skin fibroblasts have been investigated by means of an ultrasensitive near-infrared spectrometer with submicrosecond time resolution. The results indicate that the 1O2 kinetics are site-dependent. On one hand, the production of 1O2 is slower in the lysosomes than in the nucleus. On the other hand, 1O2 is able to escape out of the cells when photosensitised in the nucleus, while 1O2 photosensitized in the lysosomes is confined. Despite showing a lifetime in the microsecond time domain, the decay of 1O2 is governed by interactions with the biomolecules within the organelle there it is produced.
The uncertainty as to the intracellular site of 1O2 production may be removed by the use of genetically-encoded photosensitisers, which can be expressed in any desired organelle. Towards this end, the ability of some fluorescent proteins (GFPs) to photosensitise 1O2 has been studied. Some of the studied proteins are able to produce 1O2 albeit with a very low quantum yield. The results obtained are compared to those of the synthetic GFP chromophore and indicates that the protein scaffold not only plays a role in modulating the photophysical properties of the chromophore but also has a protective function from collisional quenching.
Finally, the two-photon absorption properties of tetraphenylporphycene and its palladium (II) complex have been determined. These compounds are ca. 100-fold more efficient two-photon 1O2 photosensitisers than their isomeric porphyrin counterparts, with two-photon absorption cross sections δ ~ 25 GM. Qualitative symmetry-based arguments are provided to explain the excellent two-photon properties and the prospects for photodynamic therapy are discussed.
Toth, Laszlo Daniel. "Light Condensation and Localization in Disordered Photonic Media: Theory and Large Scale ab initio Simulations". Thesis, 2013. http://hdl.handle.net/10754/290921.