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 23 for “"Fibre sensors"”.
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Optical fibre sensors and their interrogation
… in the fabrication and understanding of type IA fibre Bragg gratings, the uses of said gratings as optical sensors and the interrogation of optical sensors using tilted fibre Bragg gratings. This thesis presents the most detailed study of type IA gratings performed to date and provides the basis …
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Novel opto-electronic and plastic fibre sensors
… components or it can incorporate optical fibres to allow for EMI free and remote operation. The sensor is implemented using Plastic Optical Fibres (POF) as these offer considerable advantages over glass fibres or glass fibre bundles. The sensor head consists of three POFs positioned side …
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Distributed optical-fibre sensors for monitoring mechanical strain and disturbance
… capable of detecting disturbance of optical fibre cables, for application in protection of telecommunications infrastructure. Initially, three types of sensor were investigated, however after preliminary experimental and theoretical work it was decided to concentrate on a novel …
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Distributed optical fibre sensors based on the coherent detection of spontaneous Brillouin scattering
… of a distributed temperature and strain optical fibre sensor based on the coherent detection of spontaneous Brillouin scattering. To further improve the sensing range and the sensor's performance, the use of Raman amplification was investigated utilising different Raman pump configurations. Using …
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Intensity based interrogation of optical fibre sensors for industrial automation and intrusion detection systems
In this study, the use of optical fibre sensors for intrusion detection and industrial automation systems has been demonstrated, with a particular focus on low cost, intensity-based, interrogation techniques. The use of optical fibre sensors for intrusion detection systems to secure residential, …
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Design and characterisation of long period grating (LPG) - based optical fibre sensors for acoustic wave detection
Fibre optic sensors have demonstrated a broad range of commercial potential due to their intrinsic characteristics such as low loss, very small size, light weight and immunity to electromagnetic interference. Representing one type of optical fibre sensors, long period gratings (LPGs) have shown a …
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Optical fibre refractive index, voltage and strain sensors : fabrication and applications
… study of intensity and wavelength-based optical fibre sensors (OFSs) for various applications in three major sensing areas: refractive index (RI), voltage and strain. The thesis aims to provide detailed information on the design and performance of particular intensity-based and wavelength-based …
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Magnetophotonic sensor systems for fibre-optic magnetic diagnostics in tokamak fusion reactors
… high performance in adverse conditions, optical fibre sensors may be the most appropriate alternative measurement technology. However, in order to reap the benefits associated with fibre sensors - such as minimised wiring, serial multiplexing, and electrical and chemical passivity - a new class …
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Distributed optical fibre smart sensors for acoustic sensing in the structural health monitoring of robust aerospace vehicles
The use of distributed optical fibre smart sensors for the detection of acoustic signals in the Structural Health Monitoring (SHM) of robust aerospace vehicles has been demonstrated. Current distributed optical fibre sensors are multiplexed along a single fibre. Inherent problems exist with a …
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Low coherence fibre interferometry with a multi-wavelength light source
… of study of the multi-wavelength low coherence fibre interferometry. The development and performance of the all-fibre interferometric measurement systems utilising multi-wavelength combination sources are described. Principal aspects of the low-coherence sensor interrogation scheme are analysed …
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An investigation into using optical amplifiers for enhancing Brillouin based optical time domain reflectometry
Distributed fibre sensors have been successfully demonstrated and used in various industries for performing continuous measurements of the physical parameters such as temperature and strain. However, the measurement range and the performance of such sensors are limited by the intrinsic attenuation …
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Temperature measurement using rare earth doped fibre fluorescence
Optical fibre sensors have been developed to measure a wide range of parameters and in many circumstances show significant advantages over conventional measurement techniques. This thesis investigates a relatively new method of measuring temperature using optical fibres, known as the fluorescence …
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Exploitation of fibre characteristics in temperature sensing and radio-over-fibre applications
… advance in the development of microelectronic sensors, optical fibre sensors are widely investigated because of their advantageous properties over the electronics sensors such as their wavelength multiplexing capability and high sensitivity to temperature, pressure, strain, vibration and …
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Fibre optic pressure sensor for downhole monitoring in the oil industry
… be 35% on average for North Sea oil-wells.<br/>Fibre-optic sensors have the potential to measure many downhole parameters. However, high-temperature, high-pressure (HTHP) fluids are shown to have adverse effects on fibre pressure-sensors and cables. All unprotected, silica-fibre, pressure …
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Fibre optic sensor for speed measurement
… devices. There is however a demand for low-cost sensors capable of operating in potentially hazardous environments in which optical fibre sensors are more suited. In this thesis the development of a non-intrusive speed measurement sensor, based on optical technology is described. The optical …
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High Resolution Distributed Sensing Using Exposed-Core Fibres
Distributed fibre sensors were proposed more than 40 years ago, with their primary applications in physical sensing for civil infrastructure monitoring. Based on optical frequency domain reflectometry (OFDR), this thesis extends distributed sensing to biomedical applications, with a focus on the …
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In-situ deformation monitoring of aerospace qualified composites with embedded improved draw tower fibre Bragg gratings
Aerospace certified fibre reinforced plastics (FRPs) are extreme performing construction materials, which today are increasingly applied in primary structures of the new generation aircrafts (e.g. Boeing 787, Airbus 350, Bombardier C-Series), such as the fuselage, the wings and the fin. An …
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In-situ cure monitoring of epoxy resin systems
… at Brunel University to develop novel optical fibre sensors capable of monitoring the cure state of an epoxy/amine resin system. The sensors were of simple construction, consisting of an optical fibre from which the silicone cladding layer had been removed over a short length. This stripped …
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Measurement of gas bubbles in a vertical water column using optical tomography.
… an investigation into the application of optical fibre sensors to a tomographic imaging system for use with gas/water mixtures. Several sensing techniques for measurement of two component flow using non-intrusive techniques are discussed and their relevance to tomographic applications considered. …
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Optical fibre-based minimally-invasive blood glucose monitoring system.
… to have been developed and used. However, these sensors are problematic. They are invasive in nature and have bio-compatibility issues. Also, these electrochemical sensors are rendered unstable due to the electroactivity of other blood constituents, therefore requiring frequent recalibration. …
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