Global ETD Search
Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
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Showing 1 to 20 of 21 for “"optical fiber sensor"”.
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Axial offset effects upon optical fiber sensor and splice performance
A kind of intensity modulated fiber sensor utilizing axial offset parameter is proposed. The theoretical analysis and experimental characteristics of this sensor are described. All the theoretical results derived in this thesis are based on assuming a uniform power distribution in the fibers. An …
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Imbedded optical fiber sensor of differential strain and temperature in graphite/epoxy composites
A novel optical fiber sensor for the measurement of strain and temperature in graphite-epoxy composite materials using differential interferometry is described. The sensor uses two single-mode optical fiber waveguides imbedded within the composite during prepreg ply lay-up. Strain and temperature …
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Parameter identification of a flexible beam using a modal domain optical fiber sensor
An optical fiber sensor is used for identification of a cantilevered beam under conditions of various concentrated mass loadings. A model of the sensor as well as the dynamic system is developed and used to test the reliability of the identification. Input/output data from an experiment is gathered …
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Real-Time Signal Processing and Hardware Development for a Wavelength Modulated Optical Fiber Sensor System
The use of optical fiber sensors is increasing widely in civil, industrial, and military applications mainly due to their, (a) miniature size, (b) high sensitivity, (c) immunity from electro-magnetic interference, (d) resistance to harsh environments, (e) remote signal processing ability, and, (f) …
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Optical Path Length Multiplexing of Optical Fiber Sensors
Optical fiber sensor multiplexing reduces cost per sensor by designing a system that minimizes the expensive system components (sources, spectrometers, etc.) needed for a set number of sensors. The market for multiplexed optical sensors is growing as fiberoptic sensors are finding application in …
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Optical fiber sensors for advanced civil structures
… is to develop, analyze, and implement optical fiber-based sensors for the nondestructive quantitative evaluation of advanced civil structures. Based on a comparative evaluation of optical fiber sensors that may be used to obtain quantitative information related to physical perturbations …
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Photoinduced, refractive-index gratings in germanium-doped two-mode, elliptical-core optical fibers
… of germanium-doped, two-mode, elliptical-core fibers are found to affect the differential phase modulation between the co-propagating LP₀₁ and LP₁₁ even modes. The modal beat length of a two-mode fiber grating is found to vary inversely with strain induced to the fiber and leads to a new type …
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Sapphire fiber in optical sensors
The physical and optical properties of sapphire fiber has been investigated in an effort to create a high temperature optical fiber sensor. Sapphire fiber demonstrates high optical attenuation. This attenuation is very sensitive to injection conditions, and roughly proportional to the cube of the …
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Controlled Fabrication System of Fabry-Perot Optical Fiber Sensors
The use of optical fiber sensors is increasing widely in industry, civil, medicine, defense and research. Among different categories of these sensors is the Extrinsic Fabry-Perot interferometer (EFPI) sensor which is inherently simple and requires only modest amount of interface electronics. These …
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Mechanical and optical behavior of a novel optical fiber crack sensor and an interferometric strain sensor
The proper interpretation of measurements from an optical fiber sensor requires a full understanding of its mechanical response to external action and the corresponding change in optical output. To quantify the mechanical behavior it is necessary to know the mechanical properties of the fiber …
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Fiber optic sensors and networks for U.S. Navy shipboard tests and trials
… organization, telemetry cables for electrical sensors are strung throughout the ship immediately prior to the test being conducted. As the shipboard tests and trials become more numerous and complex this philosophy becomes expensive from a labor and materials point of view. This thesis proposes …
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Detecção de barras quebradas em motores de indução utilizando sensor magnetostrictivo composto aplicado em redes de Bragg em fibras ópticas
… a failure occurs. In this work, a magnetic sensor based on fiber Bragg grating (FBG) and magnetostrictive composite made of Terfenol-D particulates immersed in epoxy resin matrix applied to induction motor is shown to be capable of detecting rotor broken bars in high voltage induction …
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Exploring low-cost deep ocean sensing utilizing undersea cable networks
… and three possible concepts of ocean network sensors attached to telecommunications repeaters. In-depth interviews of stakeholders were conducted. We discuss what parameters are important to measure. We discuss information and sampling theory to flush out the tradeoff of resolution and cost, …
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High temperature tolerant optical fiber inline microsensors by laser fabrication
"Fiber sensors are particularly attractive for harsh environment defined by high temperature, high pressure, corrosive/erosive, and strong electromagnetic interference, where conventional electronic sensors do not have a chance to survive. However, the key issue has been the robustness of the …
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Innovative Plastic Optical Fiber Sensors
… thesis describes the development of new types of fiber optic sensors for the measurement of mechanical quantities such as displacement, vibration and acceleration. Also, it describes the realization of specific acquisition systems designed to interrogate the developed sensors. Since optical fibers …
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Development of Tunable Optical Filters for Interrogation of White-Light Interferometric Sensors
Interferometric fiber optic sensors have been extensively used to measure a large variety of physical, chemical and biomedical parameters due to their superior performance. At the Center for Photonics Technology of Virginia Tech, a variety of interferometric fiber optic sensors have been developed …
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ESA based fiber optical humidity sensor
… process to fabricate a Fabry-Parot Cavity based optical fiber humidity sensor. The sensing scheme bases on the refractive index change with relative humidity of the film applied to the end of optical fiber. That is, the change in reflected optical power indicates certain humidity. To achieve …
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A Quasi-distributed Sensing Network Based on Wavelength-Scanning Time-division Multiplexed Fiber Bragg Gratings
… of these structures usually requires the sensors to have such features as large area coverage, maintenance free or minimum maintenance, ultra-low cost per measurement point, and capability of operation in harsh environments. Fiber Bragg grating (FBG) has attracted considerable interest for …
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Multi-point temperature sensing in gas turbines using fiber-based intrinsic Fabry-Perot interferometers
… is well-known that using a single-mode lead-in fiber, a multi-mode fiber section as the Fabry-Perot cavity, and an additional single-mode fiber as the tail results in a structure that generates strong interference fringes while remaining robust. Though the basic principles behind these sensors …
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Development of Wearable Technologies to Titrate Rehabilitation Interventions for Individuals with Knee Osteoarthritis
L'abstract è presente nell'allegato / the abstract is in the attachment
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