Performance Evaluation of Fiber Bragg Grating Temperature Sensor
Performance Evaluation of Fiber Bragg Grating Temperature Sensor

Author: Taha Ali Alian

Publisher: LAP Lambert Academic Publishing

Published: 2014-08-11

Total Pages: 108

ISBN-13: 9783659585906

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In this work, different FBG temperature sensors are simulated and evaluated with various apodization profiles. A New apodization function is proposed with a remarkable performance compared even with the Gaussian profile. Also, and for the first time, we introduce the Nuttall apodization profile with detailed analysis. Evaluation is done under a wide range of controlling design parameters like sensor length and refractive index modulation amplitude, targeting a remarkable temperature sensing performance. New judgment techniques are introduced such as apodization window roll-off rate, asymptotic sidelobe decay level, number of sidelobes, average sidelobe level and channel isolation. Evaluation techniques like reflectivity, Full Width at Half Maximum (FWHM), and Sidelobe Suppression Ratio are also used. A study is performed on including an unapodized sensor among apodized sensors in a quasi-distributed sensing system. The obtained results demonstrated the importance of investigating the previous controlling parameters and consequently the precise control on the FBG temperature sensor various characteristics to get the optimum sensor performance according to the application needs.

Thermal Evaluation of Fiber Bragg Gratings at Extreme Temperatures
Thermal Evaluation of Fiber Bragg Gratings at Extreme Temperatures

Author: National Aeronautics and Space Administration (NASA)

Publisher: Createspace Independent Publishing Platform

Published: 2018-06-24

Total Pages: 30

ISBN-13: 9781721782567

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The development of integrated fiber optic sensors for use in aerospace health monitoring systems demands that the sensors be able to perform in extreme environments. In order to use fiber optic sensors effectively in an extreme environment one must have a thorough understanding of the sensor's capabilities, limitations, and performance under extreme environmental conditions. This paper reports on our current sensor evaluation examining the performance of freestanding fiber Bragg gratings (FBG) at extreme temperatures. While the ability of FBGs to survive at extreme temperatures has been established, their performance and long term survivability is not well documented. At extreme temperatures the grating structure would be expected to dissipate, degrading the sensors performance and eventually ceasing to return a detectable signal. The fiber jacket will dissipate leaving a brittle, unprotected fiber. For FBGs to be used in aerospace systems their performance and limitations need to be thoroughly understood at extreme temperatures. As the limits of the FBGs performance are pushed the long term survivability and performance of the sensor comes into question. We will not only examine the ability of FBGs to survive extreme temperatures but also look at their performance during many thermal cycles. This paper reports on test results of the performance of thermal cycling commercially available FBGs, at temperatures up to 1000 C, seen in aerospace applications. Additionally this paper will report on the performance of commercially available FBGs held at 1000 C for hundreds of hours. Throughout the evaluation process, various parameters of the FBGs performance were monitored and recorded. Several test samples were subjected to identical test conditions to allow for statistical analysis of the data. Test procedures, calibrations, referencing techniques, performance data, and interpretations and explanations of results are presented in the paper along with directions for futur

Structural Sensing, Health Monitoring, and Performance Evaluation
Structural Sensing, Health Monitoring, and Performance Evaluation

Author: D. Huston

Publisher: CRC Press

Published: 2010-09-21

Total Pages: 664

ISBN-13: 1420012355

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Structural health monitoring (SHM) uses one or more in situ sensing systems placed in or around a structure, providing real-time evaluation of its performance and ultimately preventing structural failure. Although most commonly used in civil engineering, such as in roads, bridges, and dams, SHM is now finding applications in other engineering envir

Fiber Bragg Grating Based Sensors and Systems
Fiber Bragg Grating Based Sensors and Systems

Author: Oleg Morozov

Publisher: MDPI

Published: 2021-08-18

Total Pages: 228

ISBN-13: 3036512861

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This book is a collection of papers that originated as a Special Issue, focused on some recent advances related to fiber Bragg grating-based sensors and systems. Conventionally, this book can be divided into three parts: intelligent systems, new types of sensors, and original interrogators. The intelligent systems presented include evaluation of strain transition properties between cast-in FBGs and cast aluminum during uniaxial straining, multi-point strain measurements on a containment vessel, damage detection methods based on long-gauge FBG for highway bridges, evaluation of a coupled sequential approach for rotorcraft landing simulation, wearable hand modules and real-time tracking algorithms for measuring finger joint angles of different hand sizes, and glaze icing detection of 110 kV composite insulators. New types of sensors are reflected in multi-addressed fiber Bragg structures for microwave–photonic sensor systems, its applications in load-sensing wheel hub bearings, and more complex influence in problems of generation of vortex optical beams based on chiral fiber-optic periodic structures. Original interrogators include research in optical designs with curved detectors for FBG interrogation monitors; demonstration of a filterless, multi-point, and temperature-independent FBG dynamical demodulator using pulse-width modulation; and dual wavelength differential detection of FBG sensors with a pulsed DFB laser.

Fiber Bragg Gratings
Fiber Bragg Gratings

Author: Andreas Othonos

Publisher: Artech House Publishers

Published: 1999

Total Pages: 448

ISBN-13:

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Fiber Bragg gratings are flexible, cost-effective and highly efficient, with a vast range of potential applications. This timely new work provides a comprehensive description of the principles and practical applications of this latest technology, which has the potential to revolutionize telecommunications and significantly impact optical fiber sensing. Here the authors explain the underlying physics and practical aspects in a clear and unambiguous manner.

Fibre Bragg Grating and No-Core Fibre Sensors
Fibre Bragg Grating and No-Core Fibre Sensors

Author: Suzairi Daud

Publisher: Springer

Published: 2018-04-23

Total Pages: 94

ISBN-13: 3319904639

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This book focuses on the development and set-up of fibre Bragg grating (FBG) and no-core fibre (NCF) sensors. It discusses the properties of the sensors and modelling of the resulting devices, which include electronic, optoelectronic, photovoltaic, and spintronic devices. In addition to providing detailed explanations of the properties of FBG and NCF sensors, it features a wealth of instructive illustrations and tables, helping to visualize the respective devices’ functions.

A Distributed Temperature Sensor Using Fiber Bragg Grating
A Distributed Temperature Sensor Using Fiber Bragg Grating

Author: Solomon Abebe Gugsa

Publisher:

Published: 2000

Total Pages: 214

ISBN-13:

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ABSTRACT: Fiber sensing technology has reached qualitatively new performances with the advent of fiber Bragg gratings. However a major problem using a fiber Bragg arises when the sensor is subject to a non-uniform temperature or strain along its length. Based on the existing signal processing schemes and sensor designs, only the average temperature or strain may be obtained. In this thesis a new technique is presented that enables us to obtain the complete temperature or strain profile along the sensing length. For this purpose, a phase discontinuity in the grating structure is introduced. This phase discontinuity breaks the symmetry of the grating profile in wavelength domain. In effect, in the reflection band of a Bragg grating we introduce a very narrow pass-band that under uniform temperature, results in the position of this window in the grating spectrum remaining unchanged. However, when a non-uniform strain or temperature is applied, the location of this wavelength window in the reflection spectrum will change. This would allow us to obtain the temperature or strain distribution along the sensor length. The signal processing used to experimentally demonstrate a distributed fiber sensor has been fully described elsewhere. A theoretical model was developed to obtain thermal distribution from the spectrum of the phase shifted Bragg grating. The theoretical model and analysis of this sensing mechanism will be discussed and experimental results will be presented in this thesis.

Effect of Strain Or Stress Applied Using Fiber Bragg Grating Sensor with the Analysis of Apodization on the Performance of the Sensor
Effect of Strain Or Stress Applied Using Fiber Bragg Grating Sensor with the Analysis of Apodization on the Performance of the Sensor

Author: Shilpa Shankar

Publisher:

Published: 2015

Total Pages: 32

ISBN-13: 9781339292922

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Abstract: This project is aimed at designing and optimizing the performance of a Fiber Bragg Grating strain sensor using different apodization profiles. FBG sensors are based on the principle that the Bragg wavelength changes with the change in grating period, length, and reflectivity. Hence, any physical parameter like stress, strain, pressure and temperature that causes a shift in the Bragg wavelength can be measured using an FBG. Ideally to use an FBG in strain sensing applications, it should have high reflectivity, low sidelobe levels and narrow full-width half maximum (FWHM). Based on this theory, an investigation of different apodization profiles on evaluation parameters such as reflectivity, sidelobes, and FWHM is performed. Blackman profile is found to be the best apodization profile, which can be used in sensing applications with the maximum reflectivity of 99.43%, minimum sidelobe levels, and narrow FWHM.