Orientador: Jose Antonio Siqueira Dias / Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Engenharia Eletrica e de Computação / Made available in DSpace on 2018-08-24T00:41:09Z (GMT). No. of bitstreams: 1 Pfrimer_FelipeWalterDafico_D.pdf: 3374919 bytes, checksum: aa34af0e6bc2013297d4bd53c2901a20 (MD5) Previous issue date: 2013 / Resumo: O crescente interesse na utilização de Grades de Bragg (FBG) em sistemas sensores pode ser explicado por algumas de suas características, que são: imunidade à interferência eletromagnética (EMI), isolamento elétrico, baixo peso, flexibilidade, e transmissão de informações a longa distância. Este trabalho apresenta uma nova técnica de interrogação capaz de medir a temperatura de uma rede de sensores de grades de Bragg em fibras ópticas, onde um circuito eletrônico realiza rotinas de controle possibilitando a implementação de uma realimentação óptica. O esquema optoeletrônico empregado é capaz de realizar a interrogação de todos os sensores da rede de maneira quase instantânea, além de permitir que novos sensores possam ser facilmente acrescentados. Um protótipo contendo dois sensores foi construído e testado para validar a técnica obtendo-se uma alta resolução de ± 1 mºC na medida de temperatura em uma faixa de 72ºC / Abstract: The increasing interest in the use of fiber Bragg gratings (FBG) in sensing systems can be explained by some of its features, which are immunity to electromagnetic interference (EMI), electrical insulation, low weight, flexibility, and long distance data transmission capability. This work presents a new interrogation technique capable of measuring temperature of Bragg gratings sensor networks in optical fibers, where an electronic circuit, capable to perform control routines, allows the implementation of an optical feedback. The optoelectronic scheme used is capable of performing the interrogation of all the sensors of the network almost instantly, and allows new sensors to be easily added. A prototype containing two channels was built and tested to validate the technique achieving a high resolution of ± 1 mºC in temperature measurements in a range of 72º C. / Doutorado / Eletrônica, Microeletrônica e Optoeletrônica / Doutor em Engenharia Elétrica

Orientador: Carlos Kenichi Suzuki / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Mecânica / Made available in DSpace on 2018-08-19T09:14:43Z (GMT). No. of bitstreams: 1 Shimahara_AlbertoYassushi_M.pdf: 5253309 bytes, checksum: ba0303e6e0217876246733070863f5fc (MD5) Previous issue date: 2002 / Resumo: Neste trabalho estudou-se a morfologia e o tamanho dos agregados de sílica em preforma porosa preparadas pelo processo VAD por MEV em conjunto com um software analisador de imagens e suas relações com os parâmetros de deposição. As observações revelam que o tamanho dos agregados variam entre 0,06 à 0,30 ?m sendo influenciados principalmente pela temperatura, que é fortemente influenciada pela distância alvo/maçarico e pela razão H2/O2 empregado. No centro da preforma a dimensão média dos agregados é maior e se reduz ao longo do raio da preforma porosa, na qual ocorre uma tendência a uma distribuição bimodal na região externa da preforma e mono modal na direção central da preforma influenciada pelo movimento de rotação do alvo. Para distâncias alvo/maçarico pequenas nota-se que os agregados se pré-sinterizam, devido à alta temperatura da chama e para distâncias longas os agregados tendem a se aglomerar ligados fragilmente entre si, devido a pouca ação da chama sobre a superfície de deposição / Abstract: In this work we studied the morphology and size of silica aggregates in porous preform prepared by VAD with SEM in conjunction with a Image Analyzer software and the relations with the deposition parameters. The observations reveal that the size of aggregates vary between 0.06 to 0.30 ?m being mainly influenced by temperature, which is strongly influenced by the distance of the target/blowtorch and reason H2/O2. In the center of the preform the average size of aggregates is greater and reduces along the radius of the porous preform, which is a trend to a bimodal distribution in the outer region of the preform and mono-modal in central direction of preform influenced by the of rotation of the target. To small distances target/blowtorch; note that the aggregates are melted due to the high temperature of flame and for long distances the aggregates are weekly connected among themselves, because the small flame action over the surface / Mestrado / Materiais e Processos de Fabricação / Mestre em Engenharia Mecânica

Orientadores: Helio Waldman, Moises Renato Nunes Ribeiro / Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Engenharia Eletrica e de Computação / Made available in DSpace on 2018-08-04T05:50:57Z (GMT). No. of bitstreams: 1 Fonseca_IguatemiEduardoda_D.pdf: 8091533 bytes, checksum: ebaaf1d7be217b7a84bbf6e9d07b7da7 (MD5) Previous issue date: 2005 / Resumo: Esta Tese propõe estratégias para o provimento de QoS óptico diferenciado em redes ópticas transparentes sob a influência do efeito não-linear de Mistura de Quatro Ondas em um cenário no qual redes clientes, como IP/MPLS e SDH, solicitam dinamicamente caminhos ópticos. Tais conexões são regidas por contratos de serviço óptico e para atender aos níveis de desempenho acordados com as redes clientes, propomos o uso de mecanismos de Controle de Admissão de Chamadas (CAC) integrados aos algoritmos de Atribuição de Rota e Comprimento de Onda (RWA). A estratégia adotada nesta Tese parte de uma abordagem conservadora para permitir que as propostas de redução de complexidade do CAC/RWA sejam propriamente avaliadas usando métricas desenvolvidas neste trabalho. Os resultados obtidos destacam a interdependência de três grandezas: nível de QoS experimentado pelas redes clientes, volume total de tráfego atendido pela rede óptica e complexidade dos algoritmos. Nesta direção, a principal contribuição da Tese é CAC/RWA's com baixíssima complexidade que se mostram eficientes no provimento de QoS sob uma limitação de camada física muito complexa, no cenário de rede com ou sem diferenciação de serviço óptico / Abstract: This Thesis proposes methodologies for differentiated optical QoS in a multi-client scenario, in which client networks (e.g. IP/MPLS and SDH) dynamically request lightpaths from a transparent optical network in which Four-Wave Mixing (FWM) imposes crosstalk among lightpaths. In order to meet Optical Service Level Agreement (OSLA), it is proposed an integrated approach towards Connection Admission Control (CAC) and Routing and Wavelength Assignment (RWA) algorithms. The strategy used in this Thesis includes a progressive approach from complex to simple algorithms to properly assess the simplified control, of FWM through new metrics such as Probability of Threshold Violation (TVP). In addition, it is shown that very simple CACRWA can be used to provide Differentiated Services. Results highlight the trade-off among three parameters: QoS levels required by client networks, total traffic transported though optica! network, and complexity of QoS algorithms. Therefore, the main contribution lies in low complexity CAC/RWA algorithms to tackle a very complex physical impairment, even encompassing scenarios with differentiated requirements for OSLA / Doutorado / Telecomunicações e Telemática / Doutor em Engenharia Elétrica

Experimental observation of the 1D Kerr-Type cavity soliton<p><p>Temporal cavity solitons constitute a remarkable family of light pulses. They don’t spread nor suffer losses and circulate indefinitely, round-trips after round-trips, along the closed path of a nonlinear cavity. To maintain their shape and power, they simply draw some energy from a continuous-wave external beam. Being robust attracting states, they can be easily written by an external pulse and naturally provide reshaping and wavelength conversion functionalities. We experimentally demonstrated the generation of such solitons. We were able to provide precise temporal and spectral characterization along with long-term observation. We also wrote the solitons in pairs and in data streams, showing that our fiber cavity could potentially be used as an all- optical buffer capable of storing 45,000 bits at 25G bits/s. These results have been recently published in Nature Photonics<p><p>High repetition-rate pulse train generation through dissipative modulation instability in a passive fiber resonator<p><p>In the early 90’s, a cavity configuration which allows for the generation of stable pulse trains through dis- sipative modulational instability was proposed. The experimental implementation of the so-called MI laser was demonstrated a few years later. Although the ideal parameters for the generation of a pulse train with a repetition rate in the THz range are easily deduced from the theory, no realization in that frequency range has been reported due to practical issues. Thanks to the tuning of the overall cavity dispersion based on the use of special fibers, we recently demonstrated the generation of a 1.6 THz repetition-rate optical pulse-train.<p><p>Theoretical and experimental study of nonlinear symmetry breaking induced by the order dispersion in a passive fiber resonator<p><p>In the regime of dissipative modulational instability, the repetition-rates of the generated pulse train can be tuned by changing the group-velocity dispersion (GVD) of the fiber. To reach the THz range, one has to drastically reduced the total GVD in the cavity. In that case, the next order of dispersion has to be included in the theoretical model describing the evolution of the intracavity field (here the mean field model). The third-order dispersion induces a drift of the pattern and an asymmetry in the spectrum. Both these effects can be precisely calculated by a multi-scale model describing the field evolution above threshold. This theoretical work has been confirmed by experimental measurements of the spectral asymmetry. / Doctorat en Sciences de l'ingénieur / info:eu-repo/semantics/nonPublished

Les travaux réalisés dans ce manuscrit portent sur la fabrication de fibres optiques microstructurées (FOMs) à cœur suspendu en verre de tellurite pour la génération de supercontinuum au-delà de 2µm. Pour atteindre notre but nous avons tout d'abord réalisées les études des propriétés thermiques et optiques des verres TeO2-ZnO-R2O et TeO2-WO3-R2O (où R= Li, Na et K). La composition du verre 80TeO2-10ZnO-10Na2O (% molaire) a été sélectionnée pour la fabrication des FOMs destinées aux caractérisations du développement des effets non linéaires. La synthèse sous atmosphère sèche et oxydante nous a permis de réduire la concentration des groupements hydroxyles d’un facteur 30 par rapport à la fabrication du verre sous air. L’utilisation d'agents déshydratants (ZnF2 et TeCl4) permet d'abaisser encore la concentration des groupements OH jusqu’à quelques ppm. La composition du verre 80TeO2-5ZnO-5ZnF2-10Na2O donne une fibre transparente jusqu’à 4 µm laissant apparaître l’influence de l’absorption multiphonon. Utilisant les précurseurs commerciaux les plus purs nous avons pu réaliser une fibre de tellurite avec de très faibles pertes à 0,1 dB/m.Nous avons fabriqué des FOMs à cœurs suspendus avec des diamètres de cœurs variant de 2,7 µm à 3,5 µmet permettant de gérer la dispersion chromatique et de ramener la longueur d'onde du zéro dispersion entre 1500 nm et 1660 nm. Pour optimiser la génération du supercontinuum nous avons utilisé des sources laser pulsées pico- et femtosecondes pour pomper les fibres en régime de dispersion anormale. En parallèle aux mesures expérimentales, nous avons effectué des modélisations numériques basées sur la résolution de l'équation de Schrödinger non-linéaire généralisée. Les résultats expérimentaux, en bon accord avec les simulations, nous ont permis d'obtenir un élargissement spectral s’étalant de 850 nm à 2850 nm avec un niveau de puissance de sortie de 112 mW, dont l'extension à plus grandes longueurs d'ondes dans l'infrarouge est encore pour l'instant fortement limitée par l’absorption des groupements hydroxyles. Cependant la déshydratation du matériau, même si elle doit encore être améliorée a permis de montrer que lors de pompage à 2000-2200 nm le supercontinuum peut atteindre 4000-4500 nm, gamme de longueurs d’onde à partir de laquelle l’absorption multiphonon commence à être perceptible / The work reported in this thesis deals with the fabrication of suspended core tellurite microstructured optical fibers (MOFs) for supercontinuum generation beyond 2 µm. In order to reach our aim, we first studied thermal and optical properties of TeO2-ZnO-R2O and TeO2-WO3-R2O (where R = Li, Na and K) glasses. The glass 80TeO2-10ZnO-10Na2O (molar %) has been chosen in order to make MOFs for characterization of the generated non linear optical effects. Synthesis performed under dry and oxidative atmosphere allowed us to reduce the hydroxyl groups concentration by a factor of 30 compared to fabrication in air atmosphere. Use of dehydrating agents (ZnF2 and TeCl4) allowed to reduce again the OH groups concentration down to a few ppm. The glass composition 80TeO2-5ZnO-5ZnF2-10Na2O increases the fiber transparency up to 4 µm letting the influence of multiphonon absorption appear. Using the purest commercial raw powders, we have fabricated one tellurite fiber exhibiting very low losses (0,1 dB/m). We have fabricated suspended core MOFs with a core diameter varying from 2,7 µm up to 3,5 µm allowing to deal with the chromatic dispersion and to shift the zero dispersion wavelength down to the 1500-1660 nm range. In order to optimize the supercontinuum generation, we have used pico- and femtosecondes pulsed laser sources to pump the fibers in anomalous dispersion regime. In parallel to the experimental measurements, we have performed numerical simulations based on the resolution of the generalized nonlinear Schrödinger equation. The experimental results, in good agreement with the simulations, allowed us to point out a spectral broadening expending from 850 nm up to 2850 nm with a total output power of 112 mW, with an extinction near the longest infrared wavelengths which is again strongly limited by the hydroxyl groups absorption. However, the dehydrated material, even though it needs to be improved further, allowed to show that by pumping at 2000-2200 nm, the supercontinuum can reach 4000-4500 nm, the wavelength range from which the multiphonon absorption starts to be perceptible

Thanks to their capability of transmitting light with low loss, optical fibers have found a wide range of applications in illumination, imaging, and telecommunication. However, since the light guided in a regular optical fiber is well confined in the core and effectively isolated from the environment, the fiber does not allow the interactions between the light and matters around it, which are critical for many sensing and actuation applications. Specially shaped optical fibers endow the guided light in optical fibers with the capability of interacting with the environment by modifying part of the fiber into a special shape, while still preserving the regular fiber’s benefit of low-loss light delivering. However, the existing specially shaped fibers have the following limitations: 1) limited light coupling efficiency between the regular optical fiber and the specially shaped optical fiber, 2) lack special shape designs that can facilitate the light-matter interactions, 3) inadequate material selections for different applications, 4) the existing fabrication setups for the specially shaped fibers have poor accessibility, repeatability, and controllability. The overall goal of this dissertation is to further the fundamental understanding of specially shaped fibers and to develop novel specially shaped fibers for different applications. In addition, the final part of this dissertation work proposed a microfluidic platform that can potentially improve the light-matter interactions of the specially shaped fibers in fluidic environments. The contributions of this dissertation work are summarized as follows: 1) An enhanced fiber tapering system for highly repeatable adiabatic tapered fiber fabrications. An enhanced fiber tapering system based on a novel heat source and an innovative monitoring method have been developed. The novel heat source is a low-cost ceramic housed electric furnace (CHEF). The innovative monitoring method is based on the frequency-domain optical transmission signal from the fiber that is being tapered. The enhanced fiber tapering system can allow highly repeatable fabrication of adiabatically tapered fibers. 2) A lossy mode resonance (LMR) sensor enabled by SnO2 coating on a novel specially shaped fiber design has been developed. The developed LMR sensor has a D-shape fiber tip with SnO2 coating. It has the capability of relative humidity and moisture sensing. The fiber-tip form factor can allow the sensor to be used like a probe and be inserted into/removed from a tight space. 3) Specially shaped tapered fibers with novel designs have been developed for integrated photonic and microfluidic applications. Two novel specially tapered fibers, the tapered fiber loop and the tapered fiber helix have been developed. The tapered fiber loop developed in this work has two superiority that differentiated itself from previous works: a) the mechanical stability of the tapered fiber loop in this work is significantly better. b) the tapered fiber loops in this work can achieve a diameter as small as 15 ?m while still have a high intrinsic optical quality factor of 32,500. The tapered fiber helix developed in this work has a 3D structure that allows it to efficiently deliver light to locations out of the plane defined by its two regular fiber arms. Applications of the tapered fiber helices in both integrated photonic device characterizations and microparticle manipulations have been demonstrated. 4) Developed an acrylic-tape hybrid microfluidic platform that can allow function reconfiguration and optical fiber integration. A low-cost, versatile microfluidic platform based on reconfigurable acrylic-tape hybrid microfluidic devices has been developed. To the best of the author’s knowledge, this is the first time that the fabrication method of sealing the acrylic channel with a reconfigurable functional tape has been demonstrated. The tape-sealing method is compatible with specially shaped fiber integrations.

All-optical signal processing has grown over the last decade due to the demand for high-speed and high-bandwidth data processing. The main objective of all-optical signal processing is to avoid signal conversions from the optical domain to electrical domain and then back to optical, which introduces noise and bottlenecks data transmission speeds. These conversions can be avoided by manipulating light using an optical medium, e.g. an optical fiber, and taking advantage of the nonlinear response of the medium's dipoles to an external electric field. Nonlinear effects arising from the third-order nonlinearities, such as the Kerr effect, allow for an intense light beam to modify the refractive index of a medium through which it propagates. As a consequence, the phase of the light beam changes as it propagates and new frequencies are generated; this phenomenon is referred to as self-phase modulation (SPM). Light's ability to modify not only its own properties but also the properties of other co-propagating beams has been widely applied in telecommunications to create integrated all-optical data regenerators. While optical fibers are mainly utilized to transmit data at extreme speeds, they can also act as sensors when considering the reflected signal as opposed to the transmitted signal. Surprisingly, most of the fiber sensing field relies on electrically-driven components for manipulating light and does not take advantage of all-optical signal processing capabilities. In this thesis, we demonstrate the use of the nonlinear Kerr effect to improve aspects of both fiber point and distributed sensing. These sensing scenarios respectively refer to the use of a fiber as a single sensing element, and to the detection of external perturbations continuously along the entire length of the fiber. The sensing improvement are obtained by first inducing a sinusoidal modulation on the light before it experiences self-phase modulation in a nonlinear medium, leading to the generation of optical sidebands. By judiciously adjusting the peak power of the light and extracting a specific sideband, multiple all-optical signal processing functions are achieved. First, high extinction ratio pulses can be generated by extracting a higher-order sideband, which allows for extending the sensing distance of distributed fiber-based sensors. The extinction ratio refers to the ratio between the pulse peak and pedestal powers. To quantify the generated extinction ratios, we develop a measurement technique based on a single-photon counter and measure a pulse exhibiting a 120 dB extinction ratio, which was originally created by an electro-optic modulator with a 20-dB extinction ratio. Second, all-optical peak power stabilization can be achieved by extracting the first-order SPM-generated sideband. We utilize this technique to stabilize the peak power of an optical pulse sent to a distributed fiber sensor. We demonstrate that this stabilization technique allows for the detection of applied vibrations that would otherwise remain buried in the background noise. Third, we demonstrate an all-optical scheme, based on sinusoidally-modulated light experiencing SPM, that enables the magnification of fluctuations in the peak power intensity of a pulsed signal. The light's peak power at the entrance of the nonlinear medium is adjusted to reach a power regime yielding a magnification factor of 2m+1, when extracting the mth-order SPM-generated sideband. Finally, we propose a new sensing scheme composed of two all-optical signal processing steps to allow for the detection of environmental perturbations previously too small to be detected by a given intensity-based fiber sensor.

Le développement de nouvelles fibres optiques en silice repose sur l’insertion des ions luminescents (ions de terres rares) dans des nanoparticules diélectriques. Dans ce contexte, la taille des particules est un paramètre clef qu’il convient de contrôler afin de bénéficier des nouvelles propriétés. Pour répondre à cet impératif, l’objectif de cette thèse était double. Premièrement, dans un objectif de structuration, il a été important d’étudier l’évolution des caractéristiques du matériau au cours de la fabrication, et deuxièmement, l’évolution des propriétés de luminescence avec les caractéristiques du matériau. La première partie de ce manuscrit décrit les différents types d’évolution des nanoparticules qui ont été observées au cours de ce travail de thèse. La réaction chimique de nanoparticules avec la matrice en silice est abordée dans l’étude du dopage par des nanoparticules de LaF3. Une observation originale de l’allongement et de la fragmentation de particules durant l’étirage en fibre optique est présentée. L’évolution thermodynamique des particules au cours de l’étirage, ainsi que l’influence des paramètres de l’étirage sont abordées. Enfin, la seconde partie de ce manuscrit se focalise sur le lien entre le matériau et ses propriétés spectroscopiques (Tm3+, Er3+). Les résultats montrent notamment que l’ajout de lanthane dans les fibres optiques dopées aux ions thulium augmente les pertes optiques, mais permet aussi d’augmenter la durée de vie du niveau 3H4 du Tm3+ jusqu’à un record de 58 μs pour une fibre transparente (pertes inférieures à 0,1 dB.m−1). Ces résultats confirment ainsi la nécessité d’un compromis sur la taille des particules et l’importance de ces travaux sur leurs possibilités de structuration. / The development of new silica-based optical fibers is relies on the insertion of luminescent ions (rare-earth ions) in dielectric nanoparticles. In this context, particle size is a key parameter that should be controlled in order to benefit from the new properties. To reach this goal, the objective of this thesis was twofold. Firstly, it was important to understand, to engineer its structuration, the evolution of the characteristics of the material during its fabrication process, and secondly, the evolution of the spectroscopic properties with the characteristics of the material. The first part of this manuscript describes the different types of evolution of the nanoparticles that were observed during this thesis work. The chemical reaction of nanoparticles with the silica matrix is discussed in the study of LaF3-nanoparticles doping. Also, an original observation of the elongation and the break-up of particles during the fiber drawing are presented. The thermodynamic evolution of the particles during the fabrication process as well as the influence of its parameters are discussed. Finally, the second part of this manuscript focuses on the link between the material and its spectroscopic properties (Tm3+, Er3+). In particular, the addition of lanthanum in the Tm3+-doped fibers increased the optical losses, but also enabled the increase of the lifetime of the 3H4 level up to a record in silica of 58 μs (optical losses below 0,1 dB.m−1). These results highlight the need for a compromise on particle size and the importance of this work on structuring possibilities.

Thanks to their capability of transmitting light with low loss, optical fibers have found a wide range of applications in illumination, imaging, and telecommunication. However, since the light guided in a regular optical fiber is well confined in the core and effectively isolated from the environment, the fiber does not allow the interactions between the light and matters around it, which are critical for many sensing and actuation applications. Specially shaped optical fibers endow the guided light in optical fibers with the capability of interacting with the environment by modifying part of the fiber into a special shape, while still preserving the regular fiber’s benefit of low-loss light delivering. However, the existing specially shaped fibers have the following limitations: 1) limited light coupling efficiency between the regular optical fiber and the specially shaped optical fiber, 2) lack special shape designs that can facilitate the light-matter interactions, 3) inadequate material selections for different applications, 4) the existing fabrication setups for the specially shaped fibers have poor accessibility, repeatability, and controllability. The overall goal of this dissertation is to further the fundamental understanding of specially shaped fibers and to develop novel specially shaped fibers for different applications. In addition, the final part of this dissertation work proposed a microfluidic platform that can potentially improve the light-matter interactions of the specially shaped fibers in fluidic environments. The contributions of this dissertation work are summarized as follows: 1) An enhanced fiber tapering system for highly repeatable adiabatic tapered fiber fabrications. An enhanced fiber tapering system based on a novel heat source and an innovative monitoring method have been developed. The novel heat source is a low-cost ceramic housed electric furnace (CHEF). The innovative monitoring method is based on the frequency-domain optical transmission signal from the fiber that is being tapered. The enhanced fiber tapering system can allow highly repeatable fabrication of adiabatically tapered fibers. 2) A lossy mode resonance (LMR) sensor enabled by SnO2 coating on a novel specially shaped fiber design has been developed. The developed LMR sensor has a D-shape fiber tip with SnO2 coating. It has the capability of relative humidity and moisture sensing. The fiber-tip form factor can allow the sensor to be used like a probe and be inserted into/removed from a tight space. 3) Specially shaped tapered fibers with novel designs have been developed for integrated photonic and microfluidic applications. Two novel specially tapered fibers, the tapered fiber loop and the tapered fiber helix have been developed. The tapered fiber loop developed in this work has two superiority that differentiated itself from previous works: a) the mechanical stability of the tapered fiber loop in this work is significantly better. b) the tapered fiber loops in this work can achieve a diameter as small as 15 ?m while still have a high intrinsic optical quality factor of 32,500. The tapered fiber helix developed in this work has a 3D structure that allows it to efficiently deliver light to locations out of the plane defined by its two regular fiber arms. Applications of the tapered fiber helices in both integrated photonic device characterizations and microparticle manipulations have been demonstrated. 4) Developed an acrylic-tape hybrid microfluidic platform that can allow function reconfiguration and optical fiber integration. A low-cost, versatile microfluidic platform based on reconfigurable acrylic-tape hybrid microfluidic devices has been developed. To the best of the author’s knowledge, this is the first time that the fabrication method of sealing the acrylic channel with a reconfigurable functional tape has been demonstrated. The tape-sealing method is compatible with specially shaped fiber integrations.

Les sources de paires de photons corrélés sont des composants clés nécessaires aux réseaux de télécommunications quantiques. Réaliser directement ces sources à partir de fibres optiques permet de minimiser les pertes d'insertion. Nous proposons de concevoir une telle source à partir d'une fibre optique étirée. La fibre étirée possède un diamètre pouvant descendre à moins de 500 nm sur une longueur de quelques centimètres. Le faible diamètre de la section étirée favorise les effets non linéaires, tandis que les sections non étirées permettent de connecter avec de très faibles pertes cette fibre étirée avec les fibres des réseaux de télécommunication.Dans cette thèse, nous présentons donc une conception d’une nouvelle source de photons corrélés totalement fibrée à base de fibres standard de télécommunications (SMF28) étirées. Pour produire ces paires de photons nous utiliserons la fluorescence paramétrique due à la brisure de symétrie à la surface de la nanofibre en silice.Nous avons développé une technique de mesure par microscopie optique, qui permet de mesurer tout le profil de la fibre étirée avec une résolution nanométrique bien au-delà de la limite de diffraction.En parallèle, nous avons modélisé la susceptibilité non linéaire de surface de second ordre en prenant en compte l’aspect vectoriel de la propagation du champ optique dans une microfibre à deux ou trois couches. Dans un second temps, nous définissons les accords de phase modaux qui sont nécessaires pour l’obtention d’une forte fluorescence paramétrique. Nous dimensionnons cette nanofibre pour une bonne optimisation de l’efficacité de génération des paires. L'ensemble du processus de création de photons sera modélisé. / Sources of correlated photon pairs are key components required for quantum telecommunications networks. Implementing these sources directly with optical fibers minimizes the insertion losses. We propose to design such a source from a tapered optical fiber.The tapered fiber has a diameter lower than 500 nm over a length of a few centimeters. The small diameter of the tapered section favors the non-linear effects, while the unstretched sections make it possible to connect this tapered fiber with the fibers of the telecommunication networks with very low losses.In this thesis, we present a design of a new source, fully fibered of correlated photons based on standard telecommunications tapered fibers (SMF28). To produce these pairs of photons we will use the parametric fluorescence due to symmetry breaking at the surface of a silica nanofiber.We have developed an optical microscopy measurement technique to measure all the profile of tapered fibers with nanometer resolution far beyond the diffraction limit.In parallel, we modeled the second-order nonlinear surface susceptibility by taking into account the vector aspect of the propagation of the optical field in a two or three-layered microfiber. In a second step, we define modal phase matchings that are necessary to obtain a strong parametric fluorescence. We size this nanofiber for a good optimization of pairs generation efficiency. The entire process of photon creation will be modeled.