[pt] Desde o final da década de 80 a indústria de fibras óticas têm passado por avanços consideráveis. Através de técnicas controladas, as fibras ópticas podem gerar sinais associados a uma vasta gama de grandezas físicas funcionando como sensores denominados de Sensores a Fibra Óptica (SFO s). Diversas técnicas podem ser empregadas para tal, e entre as existentes a baseada em redes de Bragg é a que mais tem se destacado. O interesse por transdutores empregando esta técnica se justifica pelas vantagens proporcionadas pelo uso da luz, tais como sua capacidade de multiplexação, boa relação sinal/ruído, medições a longas distâncias, imunidade a campos eletromagnéticos, ausência de faísca, entre outras. Neste trabalho buscou-se desenvolver um transdutor e uma técnica de medição baseada em sensores a rede de Bragg para medição de vibrações mecânicas. Um acelerômetro óptico triaxial é projetado e construído. Diferentes modelos foram testados em busca das características de desempenho desejadas. Simulações numéricas empregando o método dos elementos finitos auxiliaram na decisão por melhores desenhos para o transdutor. Resultados de testes experimentais e calibrações empregando um sistema de aquisição de sinais desenvolvido são mostrados. Medições de longa duração para avaliação de estabilidade do sistema e efeitos de temperatura também são apresentados. / [en] Since the end of the 1980s, the fiber optics industry has experienced considerable advances. Through a number of controlled techniques, fiber optics can generate signals associated with a vast array of physical measures, working as sensors denominated Optical Fiber Sensors (OFS s). Many different techniques can be employed to achieve this objective. Among these, the one based on Bragg networks has received the greatest amount of attention. The interest in transducers employing this technique is justified by the advantages of using light, such as its multiplexing capability, good signal-to-noise ratio, possibility of long distance measurements, immunity to electromagnetic fields, and absence of sparks. In the present work, a transducer and measurement technique based on Bragg network sensors vibration are developed, in order to measure mechanical vibrations. A triaxial optical accelerometer is designed and built. Different models are tested in the search for the desired performance characteristics. Numerical simulations employing the finite element method help the decision making process for better transducer designs. Results from experimental and calibration tests using a newly developed signal acquisition system are presented. Long duration measurements to evaluate system stability and temperature effects are also shown.

The thesis deals with the possibility of using optical fiber as a sensor. The introduction of the thesis is devoted to the foundations of optics. In addition, the thesis deals with optical interferometry, polarization and dispersion in optical fiber. The main output of the thesis is the comparison of acoustic vibration measurements using interferometric and polarization methods and further measurements on the real route in Brno.

This thesis deals with the possibilities of energy transmission by optical fiber for the purpose of powering of electronic systems. It comprises issues of electrical energy conversion to optical energy, coupling the power into the optical fiber, coupling between fiber and opto-electric transducer, conversion of optical energy to electrical energy, and transformation on required voltage levels. The principles of such Power-Over-Fiber are discussed in the first part of the work. Various technologies for the implementation of key system parts and their effectivity are discussed. In the next part, several Power-Over-Fiber commercial devices are compared. Subsequently, systems for Power-Over-Fiber experimental implementations are proposed. They are based on the utilization of semiconductor laser, multimode fiber, photovoltaic cell and related electronic circuits. The final part of the thesis deals with the construction of experimental systems and measurement of parameters of transmitted power and efficiency.

This diploma thesis deals with the optimization of production process at ADC Czech Republic s.r.o. Primarily, the method of Lean Six Sigma is used. The first part has a form of the literary study where individual methods used within the company are described. These are further applied in the practical part. The second part presents a brief introduction of the company including the production portfolio. The last part focuses on the practical solution of particular problems of two packaging lines aiming to increase the utilization. In the thesis, the DMAIC improvement cycle is employed.

Diploma thesis focuses on a problematics of an optical networks in terms of an optical cables laying and a work with individual fibers. Thesis contains an basic physical properties which are used in a fiber optics. Methodology of correct working procedures used in fiber optics is discussed at the same time. Thesis also contains detailed documentation of realized optical connections including scheme of realized outdoor connection. 3D design of an rack case is also part of the thesis. Rack case provides an option to simulate plenty of different lengths of optical routes. Rack case is designed in 6U variant.

The thesis is focused on physical principles of signal transmission by optical fiber and effects that may have influence on such transmission. This knowledge is acquired with regard to future usage of optical fiber as a sensor for detection and localization of mechanical vibration. In the thesis, mentioned knowledge is taken in account and also there are described methods, which allow mechanical vibration for dozens of km. At the conclusion the laboratory sollution is suggested, allowing detection and localization in vast distance with possibility of real test in practice.The testing curcuits are used for measurement and results are processed for purpose of detection and localization of source. The measurement itself was made by testing curcuits and results were processed for purpose of detection and localization of source.

This work deals with the possibilities of laying and reverse lookup optical routes with the help of modern technology. Hereinafter, there are possibilities for documentation and registration of fiber optic lines. Speaking of thesis, it focuses on optical technology, advantages and disadvantages of this technology. Introduction focuses on fiber optic cable and related theoretical knowledge. Additionally, there are introduced comparisons with metallic lines. Another part is based on different searching methods for optical cables using metallic elements are analyzed in a detail. This section discusses galvanic and inductive methods. Subsequently, the thesis deals with searching for optical paths with the help of EMS (electronic marker system). Moreover, there are described individual types of electronic tags which are used in the installation of different kinds of lines. There are also briefly described seeker EMS markers, made by Dynatel. In addition to my work you can find the description of GPS (Global Positioning System) technology and routing the cable with the help of GPS system. Finally, possibility of documentation and evidence in the ArcGIS from ERSI and in the SPIDER-fiber from Gisoft is given. The overall functions of individual programs and their options are analyzed. The last section presents the implementation of laboratory tasks and programming burial markers, creating navigation in Urwigo and realisation with Openwing in Nokia phone. In the end of the work is map with markers positions.

This diploma thesis deals with an analysis of the method of propagation of optical fiber by two polarization planes. The method of light propagation is mathematically described using Jones and Stokes vectors. The first part describes wave theory of light divided by Fresnel wave theory, polarization ellipse, degenerate polarization states, parameters of polarization ellipse, Poincaré sphere and degenerated states on Poincaré sphere. Then follows Stokes and Jones polarization parameters, their vectors and Mueller matrix. In addition this paper illustrates the principle of the temperature sensor which is carried out with the help of the polarimeter and its computer program. The following is design of temperature sensor, which is composed of polarizer, photodiode, light output meter and digital multimeter. Another part of the thesis shows the measured values using the current measurement solution using polarimeter and proposed photodiode sensor. At the end of the thesis there is a comparison of the measured values for the three different temperatures that were applied to the optical fiber.

[pt] Neste trabalho é apresentado o desenvolvimento de uma estrutura automatizada para o monitoramento de fibras ópticas. Esta estrura consite em dois tipos de reflectômetros ópticos por contagem de fótons no domínio do tempo e um filtro de tendências que é utilizado para detectar as falhas em uma fibra óptica de forma automatizada. O primeiro OTDR por contagem de fótons apresenta uma faixa dinâmica de 32 dB com resolução espacial de 6 m, já o segundo OTDR apresenta uma faixa dinâmica de 14 dB e uma resolução de 3 cm. Foi demonstrada a sua capacidade de detectar falhas automaticamente em um enlace óptica e de sintonização no monitoramento de redes passivas WDM. / [en] In this work the development of an automated structure for the monitoring of optical fibers is presented. This structure consists of two types of Photon Counting Optical Time Domain Reflectometers and a trend filter that is used to detect fiber faults in an automated way. The first Photon Counting OTDR has a 32 dB dynamic range with spatial resolution of 6 m, while the second OTDR has a 14 dB dynamic range and a resolution of 3 cm. Its ability to automatically detect faults in an optical fiber link and tunability for monitoring of optical WDM networks has been demonstrated.

Les travaux de cette thèse s’inscrivent dans le cadre d’une collaboration CIFRE entre Naval Group, le Laboratoire d’Hydrodynamique, d’Energétique et d’Environnement Atmosphérique (LHEEA) de l’Ecole Centrale de Nantes et de l’Institut de Génie des Matériaux (GeM) de l’ICAM de Nantes, sur la problématique de développement d’hélices marines plus efficaces, plus discrètes, et plus respectueuses de l’environnement. Une des solutions passe par le développement de structures composites plus légères et plus flexibles, capables de se déformer passivement pour s’auto-adapter à l’écoulement incident grâce à leurs propriétés spécifiques de couplage flexion-torsion. En lien direct avec cette problématique, nous avons réalisé les travaux de thèse en deux temps. Nous avons dans un premier temps mis en place, montré la faisabilité et validé une méthode de couplage numérique fluidestructure implicite fort entre les codes commerciaux de CFD Starccm+ et de CSD Abaqus pour un cas d'application issu de résultats expérimentaux disponibles dans la littérature sur deux hydrofoils flexibles déformables. Puis dans un second temps nous avons développé, réalisé et testé, dans le tunnel hydrodynamique de l’Ecole Navale, un profil portant composite spécifiquement conçu pour s’approcher du comportement d’une hélice. L’étude expérimentale et numérique de cette configuration nous a permis i) d’éprouver l'utilisation en milieu académique et industriel de nouvelles méthodes expérimentales d'instrumentation d'une pièce composite par insertion directe de fibres optiques dans les plis de composite, et d'une méthode mixte numérique - expérimentale de calibration fine d'un modèle numérique structure ; ii) d’apporter un éclairage sur la physique de l'interaction fluidestructure se produisant sur une surface portante composite ; et iii) de préciser les limitations actuelles concernant la diffusion en milieu industriel de cette méthode de couplage numérique fluide-structure. / This Ph.D is sponsored by the French company Naval Group in collaboration with LHEEA Laboratory from Ecole Centrale de Nantes and GeM Institute from ICAM de Nantes, and deals with the development of new composite marine propellers with improved efficiency, improved acoustic discretion and more environment-friendly. One of the key solutions lies in the application of composite materials to marine structures, in order to benefit from their reduced weight, increased flexibility and bend-twist coupling capacity. Indeed, the latter enables the shape-adaptability of the structure to passively adapt to the incoming flow. To meet this challenge, we first set-up a tightly coupled numerical fluid-structure method using two commercial CFD (Starccm+) and CSD (Abaqus) solvers on two flexible hydrofoils and we validated this method against experimental results available in the literature. Second, we specifically developed a composite hydrofoil to behave closely like a marine propeller and tested it in the hydrodynamic tunnel of the Ecole Navale. Thanks to the combined experimental and numerical analysis of this composite hydrofoil we reached the following conclusions: i) we helped demonstrate the industrial application of a state-of-the-art strain measurement technique using optical fibers directly embedded within the composite plies, ii) we provided some insights into the physics of the fluid-structure interaction occurring on composite hydrofoils and iii) we presented the current limitations of this coupled numerical fluid-structure method relatively to its industrial application.