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 11 of 11 for “"otdr"”.
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High-resolution Photon Counting OTDR based Interrogation of Multiplexing Broadband FBG Sensors
… optical time domain reflectometry (pc-OTDR) based multiplexing technology. The system uses a Fresnel reflection OTDR with a zero deadzone to detect FBG sensors, which improves both the system detection ability and spatial resolution. A low reflectance FBG with broad bandwidth has been …
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High resolution optical time domain reflectometry and its applications
… resolution Optical Time Domain Reflectometry (OTDR) measurements have recently allowed spatial resolutions of less than one millimeter. These capabilities indicate that OTDR techniques may be suitable for non-conventional applications such as the determination of fiber strain. This thesis …
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Distributed optical-fibre sensors for monitoring mechanical strain and disturbance
… coherent-optical time-domain reflectometer (C-OTDR). <br/><br/>The operation of the C-OTDR has been investigated theoretically, using various models to describe coherent scattering in the optical fibre. The assumptions used in the models were applied to a numerical simulation of coherent …
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Photoinduced Fresnel reflectors in germanium-doped optical fibers
… including optical time domain reflectometry (OTDR) and spectral analysis. In-line, optical fiber Fresnel reflectors have applications as internal mirrors in intrinsic Fabry-Perot interferometric (IFPI) sensors and OTDR distributed strain sensors. Photoinduced IFPI sensors have performed well …
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Humidity sensing by optically interfacing with spectrally absorptive materials
… optical time domain reflectometer (OTDR) has been developed and a four-sensor network has been built. The resolution of measurement on the network can be better than 4% RH, but because of noise in the OTDR the resolution value is dependent on averaging time in the instrument.
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Testování přenosových vlastností vícejádrových optických vláken
… vlákna pomocí metody vložných ztrát, metody OTDR a vyhodnocením výsledků měření.
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Optical fiber sensors for advanced civil structures
… spectrum and optical time domain reflectometry (OTDR) are discussed in greater detail. Results demonstrating that spread spectrum and OTDR techniques can be used to multiplex optical fiber sensors are presented. Finally, practical considerations that have to be taken into account when …
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Temperature corrected strain measurements using optical time domain reflectometry
… of measuring temperature. Experiments on several OTDR-addressed, intensity-based optical temperature sensors are performed and a method for manufacturing small air gap splices for use in measuring strain at several places along an optical fiber are presented.
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Spontaneous brillouin scattering quench diagnostics for large superconducting magnets
… fiber using Optical Time Domain Reflectometry (OTDR) to define the spatial resolution. The spontaneous Brillouin frequency shift and linewidth as a function of temperature agree well with previous literature of stimulated Brillouin data from room temperature down to 4 K. Analyzing the frequency …
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Diode Laser Spectroscopy for Measurements of Gas Parameters in Harsh Environments
… traditional Optical Time Domain Reflectometry (OTDR) approach. Based on FC-DLS principle, calibration-free measurement of gas absorbance is experimentally demonstrated for two separate sets of gas mixtures of approximately 5% to 20% methane-air and 0.5% to 20% acetylene-air. Finally, distributed …
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Learning-based Methods for Fault Detection in Fiber-Optic Networks: Monitoring under Domain Shifts and Limited Supervision
L'abstract è presente nell'allegato / the abstract is in the attachment