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Showing 1 to 20 of 27 for “"EFPI"”.
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Theoretical and Experimental Study of Low-Finesse Extrinsic Fabry-Perot Interferometric Fiber Optic Sensors
… extrinsic Fabry-Perot interferometric (EFPI) fiber optic sensors together with their signal processing methods for white-light systems are presented. The work aims to provide a better understanding of the operational principle of EFPI fiber optic sensors, and is useful and important in …
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Fiber optic methods for nondestructive testing
… An extrinsic Fabry-Perot interferometric (EFPI) sensor is utilized for sensing acoustic emission, measuring speed and attenuation in aluminum and composite specimens. A broadband preamplifier is designed for amplifying signals from the EFPI sensor. Theoretical and practical minimum …
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Extrinsic Fabry-Perot Interferometer System Using Wavelength Modulated Source
… for the extrinsic Fabry-Perot interferometer (EFPI) sensor. Using a wavelength modulated source and a novel extended-gap EFPI, some of the limitations of interferometric signal demodulation are overcome. By scanning the output wavelength of a multilongitudinal mode laser diode through current …
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A fiber optic interferometer for measuring sub-micrometer displacements of ciliary bundles
… An extrinsic Fabry-Perot interferometer (EFPI) was developed to measure the response of a ciliary bundle that is subjected to a force applied by a glass whisker. 'Imitation bundles', similar in stiffness to living ciliary bundles, were made to test the system. The stiffness of an …
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Corrosion detection using metal coatings on fiber optic sensors
… the extrinsic Fabry-Perot interferometer (EFPI), the absolute extrinsic Fabry-Perot interferometer (AEFPI), and the long period grating (LPG) fiber optic sensor. The corrosion monitoring technique used with the EFPI and AEFPI sensors exploits the ability of a thick coating of metal to …
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Electronic Signal Processing in an Optical Fiber-Based Magnetometer
… Extrinsic Fabry-Perot Interferometric (EFPI) sensors have been used to measure a variety of physical parameters like temperature, pressure and strain. A modified version of this geometry is successfully implemented to measure low-level magnetic field densities. A complete optical fiber …
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A dual wavelength fiber optic strain sensing system
The extrinsic Fabry-Perot interferometer (EFPI) has been extensively used as a strain sensor in various applications. However, like other interferometric sensors, the EFPI suffers from ambiguity in detecting directional changes of the applied perturbation, when the operating point is at a maxima or …
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Epoxy matrix composite strain sensing and cure monitoring
… of an extrinsic Fabry-Perot interferometer (EFPI) strain sensor is described, which permits the state of cure of an epoxy matrix to be monitored, when the sensor is embedded in a polymeric matrix composite. By using a glass rod with a retroreflecting end for the target fiber in the EFPI …
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The split-cavity cross-coupled extrinsic fiber interferometer
… sensitivity. The extrinsic Fabry-Perot sensor (EFPI) is a very good candidate for smart structure applications. In this thesis, a new configuration of the extrinsic Fabry-Perot interferometer is developed and demonstrated. This new configuration, based on four-beam interference, utilizes two …
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Extrinsic Fabry-Perot Interferometric hydrogen gas sensor
… modified Extrinsic Fabry-Perot Interferometric (EFPI) sensor are presented in this work. A new custom-designed, custom-built radio frequency (RF) magnetron sputtering system has been used to deposit thin films of palladium metal along with cylindrical substrates. The surface morphology of the …
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Controlled Fabrication System of Fabry-Perot Optical Fiber Sensors
… is the Extrinsic Fabry-Perot interferometer (EFPI) sensor which is inherently simple and requires only modest amount of interface electronics. These advantages make it suitable for many practical applications. Investigating a cost-effective, reliable and repeatable method for optical fiber …
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Optical fiber sensors for advanced civil structures
… the extrinsic Fabry-Perot interferometric (EFPI) optical fiber sensor is selected as the most attractive sensor. The operation of the EFPI sensor is explained using the Kirchhoff diffraction approach. As is shown in this dissertation, this approach better predicts the signal-to-noise ratio …
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Detection and Position Location of Partial Discharges in Transformers Using Fiber Optic Sensors
… multiple extrinsic Fabry-Parot interferometric (EFPI) fiber acoustic sensors which can survive the harsh environment of oil-filled transformers. This thesis work is focused on optimal arrangement of multiple sensors to monitor and locate PD activities in a power transformer. This includes the …
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Real-Time Signal Processing and Hardware Development for a Wavelength Modulated Optical Fiber Sensor System
… modulated extrinsic Fabry-Perot interferometric (EFPI) optical fiber sensor, and then design and build all the hardware and software necessary to implement a stand-a
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Fiber inline pressure and acoustic sensor fabricated with femtosecond laser
… laser: an extrinsic Fabry-Perot interferometric (EFPI) sensor with silica diaphragm for pressure/acoustic sensing, and an intrinisic Fabry-Perot interferometer (IFPI) for temperature sensing. The scope of the dissertation work consists of device design, device modeling/simulation, laser …
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Study of Multimode Extrinsic Fabry-Perot Interferometric Fiber Optic Sensor on Biosensing
… based on extrinsic Fabry-Perot interferometry (EFPI) for the measurement of optical thickness in self-assembled thin film layers as well as for the immunosensing test. The sensor was fabricated by connecting a multimode fiber (MMF) and a silica wafer. A Fabry-Perot cavity was formed by the …
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Cross sensitivity analysis of optical fibre-based sensing for high pressure, high temperature measurement in oil and gas applications.
… of FBG and Extrinsic Fabry-Perot Interferometer (EFPI) cavity for high pressure high temperature (HPHT) measurement in oil and gas applications is reported. The FBG and EFPI are used to measure temperature and pressure respectively. This configuration is able to solve the problem of cross …
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Development of a Miniature, Semi-Distributed Sapphire Fiber Optic Thermometer for Harsh and High Temperature Environments
… based extrinsic Fabry-Perot interferometry (EFPI) temperature sensing element, as well as strides made in multiplexing the same element and reducing the error potential from cross sensitivity of the thermometer with applied strain. This work has been variously funded by Pratt & Whitney and …
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Fiber Optic Sensors for Liquid Identifications
… <p>A liquid droplet forms an extrinsic FPI (EFPI), with its effective reflectance being a function of the droplet's length. As the droplet evaporates, its length decreases. We conducted immersion tests using optical fiber tip sensors and monitored the time-transient responses of the …
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Multiplexing of interferometric fiber optic sensors for smart structure applications using spread spectrum techniques
… attached Extrinsic Fabry Perot Interferometers (EFPI) are presented. The system can be used to multiplex any type of sensor which translates the measurand into intensity variations of the light. A measure of the system efficiency is obtained using crosstalk measurements. A suppression of 40 dB …
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