Fiber Bragg Gratings
Mostrando 1-12 de 26 artigos, teses e dissertações.
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1. Solving the inverse scattering problem with differential evolution: an experimental validation
Abstract This work shows the experimental validation of a method developed for determining the strain profile applied to a fiber Bragg grating by solving the inverse scattering problem. The non-uniform strain profile is recovered by formulating an optimization problem, solved with an algorithm based on differential evolution. The method has proved to be able
J. Microw. Optoelectron. Electromagn. Appl.. Publicado em: 2018-06
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2. Influence of temperature on the refractive index sensitivities of fiber Bragg gratings refractometers
Abstract Effect of cross-sensitivity between temperature and refractive index (RI) was studied using an optical sensor based on Bragg grating inscribed in an etched multi-mode fiber (MMF). RI sensitivities of different modes were used to obtain a linear response and temperature dependence in water:glycerin solutions. Results pointed out that the absolute ave
J. Microw. Optoelectron. Electromagn. Appl.. Publicado em: 2017-04
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3. The force magnitude of a human bite measured at the molar intercuspidation using fiber Bragg gratings
Abstract This study describes a localized method – using optical fiber Bragg gratings (FBGs) – to determine the human bite force at the very moment of occlusion, in maximum intercuspidation. The FBG was encapsulated in a silicone splint between uppers and lowers first molars and avoiding pre-contact with the other teeth in a dentition model. Gypsum denta
J. Microw. Optoelectron. Electromagn. Appl.. Publicado em: 2017-04
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4. Analysis of Thermo-Mechanical Stress in Fiber Bragg Grating Used for Hydro-Generator Rotor Temperature Monitoring
Abstract Fiber Bragg gratings (FBGs) offer new possibilities to monitor accurately the rotor temperature. Dozens of sensors can be mounted in series in a single fiber and used to measure the temperature in several points of the rotor winding. Such sensors installed directly on the rotor winding surface are thermally isolated from the cooling air by a silicon
J. Microw. Optoelectron. Electromagn. Appl.. Publicado em: 2017-04
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5. Thermal Monitoring of Photovoltaic module using Optical Fiber Sensors
Abstract This paper proposes the use of fiber Bragg gratings (FBG) in thermal monitoring of photovoltaic (PV) modules. Results acquired from FBG sensors were compared with two commonly used temperature sensing techniques in PV modules: PT100 sensors and infrared cameras. The experiments were performed using a PV module in actual operating conditions (varying
J. Microw. Optoelectron. Electromagn. Appl.. Publicado em: 2016-12
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6. Experimental evaluation of the wind effects on an operating power transmission tower
Abstract Static and dynamic effects on power transmission towers can be evaluated by methodologies available in codes, which suggest the use of linear static analysis. By using numerical simulations, it is possible to observe the strong influence of the geometric nonlinear behavior of transmission cables. Dynamic effects also strongly influence this behavior
REM, Int. Eng. J.. Publicado em: 2016-09
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7. Sistema para medida simultânea de temperatura e deformação com redes de Bragg em 800 nm / Simultaneous measurement of temperature and strain using fiber Bragg gratings written at 800 nm
In recent years, fiber Bragg gratings (FBGs) have been frequently used as strain and temperature sensors. Several studies have tackled the problem of distinguishing between these two physical parameters using a dual-wavelength sensor. Although these sensors have shown good results, they have a few drawbacks, one of them being the need for two light sources w
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 01/11/2012
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8. Acopladores de cristais fotÃnicos e acesso mÃltiplo por divisÃo de cÃdigo Ãptico (OCDMA) com pulsos ultracurtos em fibras de Bragg / Photonic crystals couplers and optical code division multiple access (OCDMA) with optical ultra-short pulses in linear fiber Bragg gratings
This paper presents numerical simulation studies of propagation/switching of ultra-short pulses in photonic crystal couplers and Optical Code Division Multiple Access (OCDMA) using Fiber Bragg Grating (FBG). For coding were obtained analytically Gold codes. In the analysis of photonic crystal couplers (microstructured) investigated the properties of the prop
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 28/02/2012
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9. Algoritmos de inteligência computacional em instrumentação: uso de fusão de dados na avaliação de amostras biológicas e químicas / Computational intelligence algorithms for instrumentation: biological and chemical samples evaluation by using data fusion
Neste trabalho são apresentados métodos computacionais para o processamento de dados produzidos em sistemas de espectroscopia de impedância elétrica e sensoriamento a redes de Bragg em fibra óptica com o objetivo de inferir características das amostras analisadas. Sistemas de estimação e classificação foram desenvolvidos, utilizando os sinais isola
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 24/02/2012
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10. Performance analysis of peak tracking techniques for fiber Bragg grating interrogation systems
In this paper, we propose a spectral correlation-based technique for tracking the wavelength shift of a fiber Bragg grating. We compared this approach, by means of a Monte Carlo numerical simulation, to the typical peak tracking techniques applied in classic interrogation systems. As result, we obtained a considerable gain in terms of noise tolerance (about
J. Microw. Optoelectron. Electromagn. Appl.. Publicado em: 2012-12
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11. Implementation and characterization of the dynamic response of temperature and strain transducers based on optical fiber Bragg gratings. / Implementação e caracterização da resposta dinâmica de transdutores de deformação e temperatura a fibras ópticas baseados em redes de Bragg.
Essa dissertação de mestrado é dedicada ao estudo, desenvolvimento e caracterização da resposta dinâmica de transdutores de deformação mecânica e de temperatura baseados em grades de Bragg inscritas em fibras ópticas (FBG). Como não se encontram referências diretas na literatura da área sobre a caracterização da resposta dinâmica de sensores
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 12/09/2011
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12. MAGNETIC FIELD SENSORS BASED ON FIBER BRAGG GRATINGS / SENSORES DE CAMPO MAGNÉTICO À FIBRA ÓPTICA COM REDES DE BRAGG
Sensores magnéticos são sensores que detectam o fluxo devido a campos magnéticos que existem na região do espaço delimitada pela geometria do sensor. Cada tipo de sensor possui propriedades únicas que os tornam mais para aplicações particulares, seja na detecção de campos magnéticos estáticos ou variáveis. Esta tese desenvolveu sensores de campo
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 02/09/2011