Les travaux présentés dans cette thèse portent sur l’étude et la conception de lentilles continues en guide d’ondes à plans parallèles (PPW) pour des applications multi-faisceaux. La conversion du front d'onde est assurée par une lentille formée d’une lame et d'une cavité transversale. Ce concept, proposant une approche mécanique simplifiée et possiblement purement métallique, est particulièrement attractif pour les futurs systèmes de communications par satellites (GEO/LEO) requérants des solutions à moindre coût tout en maintenant de hautes performances. La première partie de cette thèse présente la réalisation d’un outil d’analyse numérique basée sur l’optique géométrique (GO). Une prédiction rapide et précise des performances en rayonnement est obtenue. En combinant cet outil avec des processus d’optimisation, des performances en dépointage sur un large secteur angulaire sont ensuite démontrées, incluant une stabilité des diagrammes en rayonnement (ouverture à mi-puissance, niveaux de lobes secondaires et pertes en dépointage). Un prototype fonctionnant dans la bande Ka est réalisé, validant les performances précédemment obtenues. De hautes efficacités de rayonnement sont également mises en avant sur l’ensemble de la plage de fréquence. Enfin un second prototype plus compact basé sur de multiples lentilles est proposé et étudié, démontrant des performances similaires à la première solution fabriquée et mesurée. / The activities presented in this PhD focus on the study and development of continuous parallel plate waveguide (PPW) lenses for multiple beam applications. The wave front conversion is ensured by a PPW transversal ridge and cavity. The proposed concept, based on a simplified mechanical approach and possibly full-metal, is particularly suitable for future satellite communication systems (GO/LEO) requiring low-cost antennas while maintaining high performances. The first part of the thesis deals with the development of a numerical analysis tool based on geometrical optics (GO). A fast and accurate prediction of the radiation performance is provided.Combining the tool with optimization processes, large scanning performances have been demonstrated, including a stability of the radiation pattern performance (HPBW, SLL, scan loss). A prototype working at Ka band has been manufactured, validating the performances demonstrated previously. High radiation efficiencies are also proved over the entire frequency range. Finally, a second prototype targeting performances in compactness and based on multiple lenses is proposed and studied, showing similar performances as the first solution fabricated and measured.

O Brasil é atualmente um dos maiores contribuintes de produtos agrícolas do cenário mundial, em 2010 um quarto dos produtos agropecuários em circulação no mundo eram de exportação brasileira. Com o grande desenvolvimento agropecuário, a demanda por materiais de reposição nutricional de solo, como fertilizantes, cresceu na mesma proporção que a necessidade pelo controle da qualidade desses materiais. Este controle tem sido feito em laboratórios que operam de acordo com sistemas de gestão da qualidade, os quais fornecem ferramentas e procedimentos que permitem ao laboratório gerenciar e controlar todos os fatores que possam afetar a qualidade de suas analise, sendo os materiais de referência certificados primordiais para estes sistemas de gestão. Os MR ou MRCs (material de referência certificado) são materiais conhecidos por serem suficientemente homogêneos e estáveis e que trazem em seus certificados os valores de suas propriedades e suas incertezas associadas garantindo sua rastreabilidade metrológica. Neste projeto foi desenvolvido um material de referência para fertilizantes, em parceria com o Laboratório de fiscalização do ministério da Agricultura Pecuária e Abastecimento, MAPA (LANAGRO). Foram fornecidos 6 Kg de fertilizante mineral de utilização via solo, o qual foi processado de modo a se tornar um material de referência (verificação de tamanho de partícula através de peneiras, homogeneização do material e sua posterior divisão e envase) esse material foi distribuído aos laboratórios participantes do interlaboratorial organizado pelo LANAGRO. O material foi avaliado para homogeneidade onde foi determinado que o material se encontra homogêneo. Foi realizado um estudo de estabilidade para os elementos: Calcio, cobre, ferro, manganês e zinco. Onde observou-se que todos os elementos se encontraram com estabilidade aceitável. A caracterização foi realizada através de um estudo interlaboratorial organizado pelo LANAGRO - SP contando com a participação de 13 laboratórios, que analisaram 2 amostras do material em triplicata. Os resultados fornecidos pelos laboratórios foram analisados estatisticamente de forma a fornecer os resultados de concentração esperada para os elementos: Calcio, cádmio, cobalto, cobre, cromo, chumbo, ferro, magnésio, manganês, molibdênio, níquel e zinco. A incerteza associada a cada elemento de interesse foi determinada e ao final foi produzido um material de referência com os elementos cálcio, cobre, ferro, manganês e zinco certificados e contendo os restantes dos analitos como elementos de referência. Foi realizada a publicação de um artigo de revisão na revista Trends in Analytical Chemistry intitulado \"Trends in development of certified reference materials for chemical analysis - Focus on food, water, soil and sediment matrices\" / Brazil is one of the largest contributors of agricultural products in the world, in 2010 a quarter of the world\'s agricultural products were of the Brazilian export market. With the great agricultural development, the demand for soil nutritional replacement materials, as fertilizers, grew in the same proportion as the need to control the quality of these materials. This control its been done in laboratories that work according to quality management systems, which offer tools and procedures that allow the laboratory to manage and control all factors that may affect the quality of its analysis. Reference materials or certified reference materials are essential for these management systems. MR or MRC\'s (certified reference material) are materials known to be sufficiently homogeneous and stable that carry in their certificates the values of their properties and their associated uncertainties, ensuring their metrological traceability. In this project, a reference material for fertilizers was developed in partnership with the Ministry of Agriculture, Livestock and Supply, MAPA (LANAGRO). 6 kg of mineral fertilizer was provided, which was processed to become a reference material (particle size verification through sieves, homogenization of the material and its subsequent division and packaging). these materials were distributed to the laboratories participating in the interlaboratorial organized by LANAGRO. The material was evaluated for homogeneity where it was determined that the material is homogeneous. A stability study was carried out for the elements: calcium, copper, iron, manganese and zinc. It was observed that all the elements met an acceptable stability. The characterization was performed through an interlaboratorial study organized by LANAGRO - SP with the participation of 13 laboratories, which analyzed 2 samples of the material in triplicate. The results provided by the laboratories were statistically analyzed to provide the expected concentration results for the elements: Calcium, cadmium, cobalt, copper, chromium, lead, iron, magnesium, manganese, molybdenum, nickel and zinc. The uncertainty associated with each element of interest was determined and at the end a reference material with certified calcium, copper, iron, manganese and zinc elements was produced and the remainder of the analytes contained as reference elements. A review article was published in the journal Trends in Analytical Chemistry titled \"Trends in development of certified reference materials for chemical analysis - Focus on food, water, soil and sediment matrices\"

Dans les prochaines décennies, les limites des systèmes de communications optiques actuels seront atteintes à moins d'adopter de nouvelles solutions. L'une d'elles est l'utilisation d'une nouvelle plage spectrale autour de 2 µm stimulée par l'apparition des amplificateurs fibrés dopés thulium. Dans ce manuscrit, nous nous y intéresserons dans le cadre de transmissions très courtes distances sur puces photoniques. Divers matériaux, dont le dioxyde de titane, seront ainsi explorés.Ce travail de thèse a deux principaux objectifs. D'une part, il vise à démontrer que le dioxyde de titane (TiO2), matériau encore peu exploré, est prometteur pour des applications télécoms en le comparant à des plateformes plus matures. D'autre part, il tend à introduire la bande spectrale autour de 2 µm comme une solution à envisager pour les télécommunications de nouvelle génération.Plus précisément, la première partie de cette thèse a pour but de développer une technique pour coupler efficacement la lumière dans les structures en TiO2). Pour la première fois, une configuration faisant appel à un réseau métallique enterré a été évaluée numériquement avant d'être caractérisée expérimentalement. La seconde partie présente des transmissions télécoms haut-débit (10 Gbit/s) autour de µm réalisées sans erreurs dans des guides d'ondes sub-longueur d'onde ou multimodes en dioxyde de titane, silicium ou silicium-germanium. Pour terminer, des fonctions non-linéaires sont explorées sur ces puces photoniques. Il a été ainsi démontré une conversion en longueurs d'onde à 2 µm atteignant -10dB sur silicium ou la génération du premier supercontinuum s'étalant du visible à 2 µm dans un guide d'onde en TiO2. / In the next decades, the limits of current optical communication systems will be reached unless new solutions are adopted. On of them is the use of a new spectral range around 2 µm enabled by the emergence of thulium-doped fiber amplifiers. In this thesis, we will focus on it in the context of very short distances transmissions on photonic chips. Various materials, mainly titanium dioxide (TiO2), will be explored.This thesis work has two main objectives. On the one hand, it aims to demonstrate that a material relatively unexplored, titanium dioxide, is promising for telecom applications by comparing it to more mature plateforms. On the other hand, it tends to introduce the spectral band around 2 µm as a solution to be considered for next-generation communications.More precisely, the first part of this thesis aims to develop a technique to efficiently couple light in TiO2 structures. For the first time, a configuration using a buried metallic grating was evaluated numerically and then characterized experimentally. The second part presents error-free high-speed (10 Gbit/s) telecom transmissions around 2 µm carried out in subwavelength or multimode waveguides in titanium dioxide, silicon or silicon-germanium. Finally, nonlinear functions are explored on the photonic chips. Thus, it has been demonstrated a wavelength conversion at 2 µm reaching -10dB on a silicon waveguide or the first supercontinuum generation spreading from visible to 2 µm wavelength in a TiO2 waveguide.

Made available in DSpace on 2016-04-27T16:34:00Z (GMT). No. of bitstreams: 1 Marcelo Marques de Souza.pdf: 1257833 bytes, checksum: 28c208aeaa0e534b2854225cbcbc64c4 (MD5) Previous issue date: 2009-08-31 / Secretaria da Educação do Estado de São Paulo / The objective of this study was to identify the conceptions of history textbooks for elementary school II in their differences and similarities. We use the ideas expressed by several subjects related to social institutions involved in the evaluation, selection and choice of material: the MEC, manager of the National Program of Textbooks (PNLD), with its auditors, the Academy, with its theme of researchers and the media and the journalists who asked, often, controversy over the textbooks, the Brazilian Association of Authors of Educational Books (ABRALE), representing the authors of textbooks and, in particular, the institution of school and their teachers History of the public of the State of São Paulo. All these individuals contributed their different experiences to enrich the discussion and explanation of concepts about the textbooks. As theoretical references on the school subjects, based on contributions from Chervel (1990), for a more complex understanding of the textbook references in articles from Chopin (2004), for teaching and history textbooks in Brazil, Bittencourt (1993) / O objetivo deste trabalho foi identificar as concepções de livros didáticos de história do ensino fundamental II em suas divergências e convergências. Usa as concepções expressas por vários sujeitos ligados às instâncias sociais envolvidas no processo de avaliação, seleção e escolha do material didático: o MEC, gestor do Programa Nacional do Livro Didático (PNLD), com seus pareceristas; a Academia, com seus pesquisadores do tema; a Mídia e os jornalistas que opinaram, muitas vezes, polemicamente sobre os livros didático; a Associação Brasileira de Autores de Livros Educacionais (ABRALE), representando os autores de livros didáticos; e, de forma especial, A Escola e seus professores de História da rede pública do Estado de São Paulo. Todos esses sujeitos contribuíram com suas diferentes vivências para o enriquecimento do debate e explicitação das concepções acerca dos livros didáticos. Como referenciais teóricos sobre as disciplinas escolares, pautamos nas contribuições de Chervel (1990); para uma compreensão mais complexa dos livros didáticos nos referenciamos nos artigos de Chopin (2004); para o ensino de História e livros didáticos no Brasil, Bittencourt (1993)

La plasmonique est un domaine de la nano-photonique qui étudie le comportement de la lumière à des échelles sub-longueurs d'ondes en présence de métaux. Les plasmons polaritons de surface (SPPs) sont des modes électromagnétiques qui se propagent à l'interface entre un diélectrique et un métal. Les SPPs trouvent des applications dans plusieurs domaines comme la communication et le traitement tout-optique du signal, la spectroscopie, la détection en biologie et en chimie. De nombreux composants plasmoniques (modulateurs, coupleurs, détecteurs ...) ont été démontrés ces dernières années. Cependant, leur l'intégration reste conditionnée par l'absence d'un générateur compact (pompage électrique, dimensions réduites) et par les grandes pertes ohmiques. Les techniques standards de génération de SPs nécessitent l'alignement d'un laser externe sur un prisme ou un réseau de diffraction afin d'adapter le vecteur d'onde incident avec celui du plasmon. L'approche que nous avons choisie est basée sur l'utilisation de lasers à semiconducteur ayant une polarisation transverse magnétique (TM) comme source d'excitation et de gain. Notre approche, permet d'obtenir des dispositifs compacts et facilement intégrables sur puce. Pendant ma thèse j'ai étudié expérimentalement et numériquement les performances d'un laser en fonction rapprochement du contact métallique à sa région active. La proximité du gain optique au métal est nécessaire pour la réalisation de dispositifs plasmoniques actifs. J'ai démontré la génération et l'amplification des plasmons de surface dans la bande télécom (λ=1.3µm), avec des dispositifs compacts, à base de semiconducteurs, fonctionnant par injection électrique et à température ambiante. Notamment, j'ai réalisé une architecture élégante, avec coupleur intégré, pour la génération de SPPs accessibles sur le sommet du dispositif. Un dispositif avec gaine superficielle ultrafine a permis de démontrer un mode hybride plasmonique avec une fraction consistante de champ électrique à l'interface métal/semiconducteur. Finalement, j'ai montrée que la structuration nanométrique du contact métallique réduit les pertes du mode laser. Les résultats sont renforcés par une nouvelle technique de imagerie de champ proche (SNOM) qui a permis de mesurer les SPPs à l'interface métal/or et à l'interface métal/ semiconducteur. Grâce aux mesures SNOM, il a aussi été possible de démontrer sans aucune ambiguïté l'effet de la structuration du métal sur le mode optique. / The field of plasmonics is experiencing a rapid development, due to the interest in studying the behavior of light at the nanometer scale. Key ingredients of plasmonics are the surface plasmons (SPs), electromagnetic modes localized at the interface between a metal and a dielectric. SPs rely on the interaction between electromagnetic radiation and conduction electrons at metallic interfaces or in "small" metallic nanostructures. The recent intense activity on plasmonics has been also enabled by state-of-the-art nano fabrication techniques and by high-sensitivity optical characterization techniques. These tools pave the way to promising applications (integration in electronics, chemical and biological detection...), which exploit the SP peculiarity of confining optical fields over sub-wavelength mode volumes. The number of publications concerning plasmonics has been continuously increasing over the last twenty years giving rise to a dynamic research context. Several plasmonic devices have been demonstrated during the last years (modulators, couplers, detectors ...). However their integration is limited by the absence of a compact generator (electrical pumping, small dimensions) and by the huge ohmic losses. Standard techniques for surface plasmon polariton (SPP) generation need an external alignment with a laser source on a prism or on a grating. Our approach is based on semiconductor lasers sources with a transverse magnetic (TM) polarization. Therefore, it is possible to obtain compact semiconductor devices suitable for the on chip integration. During my thesis I studied experimentally and numerically the performance of a diode laser as a function of the metal distance from its active region. The proximity of the gain to the metal is necessary to realize active plasmonic devices. I demonstrated the generation and the amplification of SPP in the telecom range (λ=1.3µm) with compact semiconductor based devices, operating at room temperature and by electrical injection. I realized an elegant architecture with an integrated coupler grating for the SPP generation. The SPPs are directly accessible at the device surface. An ultra-thin cladding device allowed the demonstration of a hybrid plasmonic laser with a consistent fraction of electric field at the metal/semiconductor interface. Finally I demonstrated that the metal patterning allows a loss reduction, decreasing the laser threshold. The results are strengthened by a new near-field technique (NSOM) which permitted to measure the SPPs at the metal/air interface and at the metal/semiconductor interface. Thanks to the NSOM we showed unambiguously the effect of the metal patterning on the optical mode.

Ce manuscrit de thèse est consacré aux condensats de polaritons dans deux semi-conducteurs à grand gap : GaN et ZnO. La première partie de ce travail se concentre sur l’étude par spectroscopie optique de deux microcavités planaires (une de GaN, l’autre de ZnO) présentant des structures et des propriétés photoniques identiques. Le régime de couplage fort lumière-matière et l’effet laser à polaritons ont pu être observés de 5 K à 300 K pour les deux microcavités. La réalisation de diagrammes de phase a mis en évidence l’impact variable des résonances avec les phonons LO sur l’abaissement du seuil laser. L’étude de la microcavité GaN a été poussée jusqu’à 350 K et nous avons pu démontrer, pour la première fois à cette température, la persistance du couplage fort et du laser à polaritons pour des conditions d’excitations optimales. La deuxième partie de ce travail est focalisée sur des guides d’onde de ZnO. Outre l’observation du régime de couplage fort de 5 K à 300 K, notre étude a pu mettre en exergue un phénomène laser inédit dans cette géométrie : le laser à polaritons horizontal. / This manuscript is devoted to polariton condensates in two wide band gap semiconductors: GaN and ZnO. The first part of this work focuses on the study by optical spectroscopy of two planar microcavities (one of GaN, the other of ZnO) sharing the same structure and the same photonic properties. The strong coupling and polariton lasing regime have been observed from 5 K to 300 K in both microcavities. The realization of phase diagrams has pointed out the inconstant impact of resonances with LO phonons on the lowering of the laser threshold. The study of the GaN microcavity has been pushed to 350 K and we have demonstrated, for the first time at this temperature, the persistence of the strong coupling regime and the polariton laser under optimal excitation conditions. The second part of this work is focused on ZnO waveguides. Besides the observation of strong coupling regime from 5 K to 300 K, our study has highlighted a new lasing effect in this geometry: the horizontal polariton laser.

Estreia, na Constituição Federal de 1988, de forma expressa, a incidência dos princípios da ampla defesa e do due process no processo administrativo, consagrando, pois, a presença efetiva do modelo Estado de Direito a emoldurar e balizar a atividade desenvolvida pelo Poder Público. Considerando, destarte, que o Estado atua não apenas por intermédio de atos administrativos isolados, mas também por via de processos, cada dia mais complexos, demandando um particular debruçar por parte dos analistas, pareceu-nos oportuno o estudo da incidência da teoria das nulidades em sede de processos administrativos. A perspectiva deste estudo, sem abandonar a teoria da invalidez dos atos administrativos, busca o aprofundamento no domínio da ocorrência de fatores que possam conduzir à nulidade e invalidade do processo administrativo tanto geral, como disciplinar perquirindo as condições necessárias para assegurar aos processos trâmites regulares, afastando os vícios e mantendo-os sempre no campo da legalidade. A perspectiva do trabalho, destarte, busca recolocar tema tão polêmico em debate e, sob a lente da investigação científica, apresentar, de modo sistematizado, as doutrinas, as teses desenvolvidas e a jurisprudência construída de modo a assegurar a evolução do tratamento jurídico oferecido ao processo administrativo para o efetivo atingimento de suas finalidades públicas. Ao administrado, de outro lado, a pesquisa se revela de interesse, porquanto põe à luz, evidenciando, os princípios pelos quais a Administração deve se pautar para que determinado ato seja válido e eficaz. Cuida-se de preservar a supremacia do interesse público, em prol dos objetivos fundamentais do standard do Estado Democrático de Direito, dentre eles, uma sociedade livre, justa e solidária / For the first time, the 1988 Brazilian Federal Constitution expressly provides for the application of the principles of fair hearing and due process of law to administrative procedures, thereby enshrining the tangible presence of the rule of law approach, whose purpose is to frame and limit the activities performed by the Government. Therefore, considering that the Government does not operate only through isolated administrative acts, but also through increasingly complex processes that require particular examination by analysts, it seems fitting to study the application of the theory of nullities in administrative procedures. Although it does not depart from the theory of invalidity of administrative acts, the focus of this study is to inquire into facts that may result in the nullity and invalidity of administrative procedures both of a general and disciplinary nature and establish the necessary conditions to ensure the regular course of procedure, thereby avoiding errors and preserving its legal integrity. Thus, this paper aims to rekindle the discussion on this controversial subject and, based on a scientific analysis, presents a systematized portrayal of the relevant doctrines, theses and case law that were produced with a view to the development of the legal framework that underpins administrative procedure and the fulfillment of its public mission. On the other hand, this research is of interest also to private individuals, as it brings to light the principles the Public Administration must observe for any given act to be considered valid and effective. Particular care is taken to preserve the paramount importance of public interest as a fundamental objective that determines the standards of a state founded on the rule of law, including a free, equal and fair society.

Ces travaux de thèse sont une contribution au projet de réalisation de matrices actives photoniques dans le cadre de la confection de lunettes à réalité augmentée. Un état de l’art des dispositifs actuels nous a permis de montrer l’encombrement engendré par l’utilisation d’un projecteur situé sur la monture. Pour s’en abstenir, l’utilisation du verre de lunette comme source d’image est limitée par la transparence des matrices actives classiques adressant un signal électrique avec des matériaux métalliques. L’utilisation de la photonique pour adresser chacun des pixels avec un signal optique guidée dans des matériaux diélectriques pourrait permettre d’en optimiser la transmission. Dans ce contexte, nos travaux concernent l’étude et la réalisation expérimentale de dispositifs incluant un guide d’onde et un système d’extraction activable. L'objectif est, d'une part, de sélectionner les matériaux et procédés technologiques adaptés pour former des lignes d'adressage photoniques et, d'autre part, d'associer les composants réalisés avec des éléments actifs permettant d’initier ou non l’extraction d’un guide d’onde. Le dispositif doit être transparent dans le visible afin de respecter les contraintes liées au secteur de l'optique ophtalmique. Dans un premier axe de recherche, des réseaux de diffraction micrométriques sont réalisés grâce au développement d’un procédé de photolithographie sur verre avant d’être imprégnés de cristaux liquides via la formation de cellules. La caractérisation, en transmission, des dispositifs formés permet d’étudier la capacité des molécules de cristal liquide à moduler l'intensité de diffraction pour passer d’un état diffractant à un état non diffractant. Une extinction de la diffraction de 90 à 99,9% selon l'épaisseur des structures est finalement mesurée avec l’application d’un champ électrique dans la cellule. La comparaison de ces résultats avec des calculs numériques permet de confirmer l’alignement des molécules à l’intérieur de la structure ainsi que leurs mobilités sous l’effet d’un champ électrique. Ce principe est, dans un second temps, étudié avec des composants photoniques et la réalisation de GMRF (Guided Mode Resonance Filter), association d'un guide d'onde et d'un réseau de diffraction. Des matériaux issus de la chimie sol-gel sont utilisés pour former des guides d'onde planaires et le développement d’un procédé de lithographie par nano-impression nous a permis d’obtenir les structures nanométriques requises. Divers bancs de caractérisation optique sont alors mis en place pour aboutir à plusieurs méthodes de couplage permettant d’obtenir une onde guidée dans le visible. Finalement, nous avons mesuré une modulation de 90% de l’intensité extraite par le GMRF via l’activation des cristaux liquides. / Ces travaux de thèse sont une contribution au projet de réalisation de matrices actives photoniques dans le cadre de la confection de lunettes à réalité augmentée. Un état de l’art des dispositifs actuels nous a permis de montrer l’encombrement engendré par l’utilisation d’un projecteur situé sur la monture. Pour s’en abstenir, l’utilisation du verre de lunette comme source d’image est limitée par la transparence des matrices actives classiques adressant un signal électrique avec des matériaux métalliques. L’utilisation de la photonique pour adresser chacun des pixels avec un signal optique guidée dans des matériaux diélectriques pourrait permettre d’en optimiser la transmission. Dans ce contexte, nos travaux concernent l’étude et la réalisation expérimentale de dispositifs incluant un guide d’onde et un système d’extraction activable. L'objectif est, d'une part, de sélectionner les matériaux et procédés technologiques adaptés pour former des lignes d'adressage photoniques et, d'autre part, d'associer les composants réalisés avec des éléments actifs permettant d’initier ou non l’extraction d’un guide d’onde. Le dispositif doit être transparent dans le visible afin de respecter les contraintes liées au secteur de l'optique ophtalmique. Dans un premier axe de recherche, des réseaux de diffraction micrométriques sont réalisés grâce au développement d’un procédé de photolithographie sur verre avant d’être imprégnés de cristaux liquides via la formation de cellules. La caractérisation, en transmission, des dispositifs formés permet d’étudier la capacité des molécules de cristal liquide à moduler l'intensité de diffraction pour passer d’un état diffractant à un état non diffractant. Une extinction de la diffraction de 90 à 99,9% selon l'épaisseur des structures est finalement mesurée avec l’application d’un champ électrique dans la cellule. La comparaison de ces résultats avec des calculs numériques permet de confirmer l’alignement des molécules à l’intérieur de la structure ainsi que leurs mobilités sous l’effet d’un champ électrique. Ce principe est, dans un second temps, étudié avec des composants photoniques et la réalisation de GMRF (Guided Mode Resonance Filter), association d'un guide d'onde et d'un réseau de diffraction. Des matériaux issus de la chimie sol-gel sont utilisés pour former des guides d'onde planaires et le développement d’un procédé de lithographie par nano-impression nous a permis d’obtenir les structures nanométriques requises. Divers bancs de caractérisation optique sont alors mis en place pour aboutir à plusieurs méthodes de couplage permettant d’obtenir une onde guidée dans le visible. Finalement, nous avons mesuré une modulation de 90% de l’intensité extraite par le GMRF via l’activation des cristaux liquides.

This dissertation consists of three essays: essay 1, Underwriting Use of Credit Information and Firm Performance ‐ An Empirical Study of Texas Property‐Liability Insurers, essay 2, Prediction of Ratings in Property‐Liability Industry when The Organizational Form Is Endogenous, and essay 3, A Discussion of Parsimonious Methods Predicting Insurance Companies Ratings. The purpose of the first essay is to investigate the influence of underwriting use of credit information on variation in insurers’ underwriting performance. Specifically, this study addresses the following two research questions: first, what firm‐level characteristics are associated with the insurers’ decision to use credit information in underwriting? second, is there a relationship between the use of credit information and variation in insurers’ underwriting performance? The empirical results indicate that larger insurance companies, companies having more business in personal auto insurance, and those with greater use of reinsurance are more likely to use credit information in underwriting. More importantly, the results indicate that use of credit information is associated with lower variation in underwriting performance, consistent with the hypothesis that use of credit information enables insurers to better predict their losses. The purpose of the second essay is to resolve the inconsistent relationship between the organizational forms (i.e., stock versus mutual insurers) and insurers’ financial strength ratings. Specifically, this study takes into account the potential endogenous nature of organizational forms to investigate the influence of organizational forms on insurers’ financial strength ratings. The empirical results from the models employed indicate that the stock dummy variable is indeed a significant predictor of insurers’ ratings and that the relationship between the stock dummy and insurers’ financial strength ratings is not affected after the endogenous nature of organizational forms is considered. However, such relationship flips to be negative when additional rating predictors are included into the models. The purpose of the third essay is to investigate whether a logistic model is consistent in its predictions within one data set and compare the predictability and classificatory performance between the regression with a set of financial variables and the regression with principal components derived from this set of financial variables. The empirical results indicate that the models’ predictability is consistent within one data set which includes two different groups of observations. Also, the findings suggest that the principal components regression as a parsimonious model achieves the similar accuracy of estimation and fit while providing clearer interpretation of the role of the significant predictors.

This study seeks to gain an insight into the experiences Lord of the Rings tourists have on guided tours in New Zealand and the role of the tour guide(s) in that experience. The study examines motivations, expectations, actual experience and its evaluation and the role of the tour leader and guides. By drawing primarily on the results of qualitative research that examined the experience of film tourists and other people involved in the film tourism industry over a span of three years, I identified underlying motivations involved in the production and consumption of film tourism. The study found that pre-tour images of Lord of the Rings and its publicity surrounding the making of the films play a significant role in the formation of film tourists' expectations. The emotional relationship towards the films and the novel by J.R.R. Tolkien had motivated film tourists to seek a meaningful and sincere experience. Furthermore, the film and its making as discussed on the DVDs, further publicised myths like the authenticity of the film production itself and the experience of great meaning for one's personal life. Consequently, the study found that most film tourists put a high significance on the sincerity of the relationships within the tour community and with the tour leader and guide(s). The film location visit itself was experienced as highly rewarding but was significantly enhanced by the presence of the tour community ('fellowship'), reenactments and the physical presence on site. This embodiment was crucial for the overall experience as it further authenticated the location visit but also the journey itself as a worthy and spiritual endeavour. It was shown that the New Zealand image of 'green', 'clean' and 'exotic otherness' has been reinforced by multiple media portraits and matches many aspects of the Middle-earth image. All film tourists judged the use of New Zealand for the portrayal of Middle-earth as 'authentic' even if they knew about J.R.R. Tolkien's British background. Furthermore, they judged their film tourism experience as authentic even though the locations were used in a fictional setting. Thus the notions of object authenticity was explored and replaced with the concepts of existential authenticity and sincerity to shift the focus towards the active process of negotiation of authenticity in the tourism experience. To understand tourists' behaviour and motivation, notions of 'spirituality' and 'pilgrimage' were also employed. The study tourists undertook a meaningful and spiritually significant journey that was enhanced through the experience of embodiment and community which suggested parallels between the religious pilgrim and the secular film tourist. Both are on a meaningful journey to distant places and follow scripted guidelines while also creating their own experience. Embodiment played an important role. Furthermore, film tourists sought the community of other believers and were willing to 'follow in the footsteps' of film stars and crew when choosing which film locations and eateries to visit as they sought places that had attained an 'aura'.