FIBER OPTIC SENSORS ppt

FIBER OPTIC SENSORS Edited by Moh. Yasin, Sulaiman W. Harun and Hamzah Arof           Fiber Optic Sensors Edited by Moh. Yasin, Sulaiman W. Harun and Hamzah Arof Published by InTech Janeza Trdine 9, 51000 Rijeka, Croatia Copyright © 2012 InTech All chapters are Open Access distributed under the Creative Commons Attribution 3.0 license, which allows users to download, copy and build upon published articles even for commercial purposes, as long as the author and publisher are properly credited, which ensures maximum dissemination and a wider impact of our publications. After this work has been published by InTech, authors have the right to republish it, in whole or part, in any publication of which they are the author, and to make other personal use of the work. Any republication, referencing or personal use of the work must explicitly identify the original source. As for readers, this license allows users to download, copy and build upon published chapters even for commercial purposes, as long as the author and publisher are properly credited, which ensures maximum dissemination and a wider impact of our publications. Notice Statements and opinions expressed in the chapters are these of the individual contributors and not necessarily those of the editors or publisher. No responsibility is accepted for the accuracy of information contained in the published chapters. The publisher assumes no responsibility for any damage or injury to persons or property arising out of the use of any materials, instructions, methods or ideas contained in the book. Publishing Process Manager Martina Blecic Technical Editor Teodora Smiljanic Cover Designer InTech Design Team First published February, 2012 Printed in Croatia A free online edition of this book is available at www.intechopen.com Additional hard copies can be obtained from orders@intechweb.org Fiber Optic Sensors, Edited by Moh. Yasin, Sulaiman W. Harun and Hamzah Arof p. cm. ISBN 978-953-307-922-6   Contents  Preface IX Chapter 1 Optical Fiber Sensors: An Overview 1 Jesus Castrellon-Uribe Chapter 2 Optical Fiber Sensing Applications: Detection and Identification of Gases and Volatile Organic Compounds 27 Cesar Elosua, Candido Bariain and Ignacio R. Matias Chapter 3 Intrinsic Optical Fiber Sensor 53 Sylvain Lecler and Patrick Meyrueis Chapter 4 Life-Cycle Monitoring and Safety Evaluation of Critical Energy Infrastructure Using Full-Scale Distributed Optical Fiber Sensors 77 Zhi Zhou, Jianping He and Jinping Ou Chapter 5 Characterization of Brillouin Gratings in Optical Fibers and Their Applications 115 Yongkang Dong, Hongying Zhang, Dapeng Zhou, Xiaoyi Bao and Liang Chen Chapter 6 Synthesis of Two-Frequency Symmetrical Radiation and Its Application in Fiber Optical Structures Monitoring 137 Oleg Morozov, German Il’in, Gennady Morozov and Tagir Sadeev Chapter 7 A Novel Approach to Evaluate the Sensitivities of the Optical Fiber Evanescent Field Sensors 165 Xuye Zhuang, Pinghua Li and Jun Yao Chapter 8 Tapered Optical Fibers – An Investigative Approach to the Helical and Liquid Crystal Types 185 P. K. Choudhury VI Contents Chapter 9 Robust Fiber-Integrated High-Q Microsphere for Practical Sensing Applications 233 Ying-Zhan Yan, Shu-Bin Yan, Zhe Ji, Da-Gong Jia, Chen-Yang Xue, Jun Liu, Wen-Dong Zhang and Ji-Jun Xiong Chapter 10 Optical Effects Connected with Coherent Polarized Light Propagation Through a Step-Index Fiber 249 Maxim Bolshakov, Alexander Ershov and Natalia Kundikova Chapter 11 Long Period Fibre Gratings 275 Alejandro Martinez-Rios, David Monzon-Hernandez, Ismael Torres-Gomez and Guillermo Salceda-Delgado Chapter 12 Long Period Fiber Grating Produced by Arc Discharges 295 Julián M. Estudillo-Ayala, Ruth I. Mata-Chávez, Juan C. Hernández-García and Roberto Rojas-Laguna Chapter 13 Fibre Sensing System Based on Long-Period Gratings for Monitoring Aqueous Environments 317 Catarina Silva, João M. P. Coelho, Paulo Caldas and Pedro Jorge Chapter 14 High-Birefringent Fiber Loop Mirror Sensors: New Developments 343 Marta S. Ferreira, Ricardo M. Silva and Orlando Frazão Chapter 15 Fiber Optic Displacement Sensors and Their Applications 359 S. W. Harun, M. Yasin, H. Z. Yang and H. Ahmad Chapter 16 Sensing Applications for Plastic Optical Fibres in Civil Engineering 393 Kevin S. C. Kuang Chapter 17 Plastic Optical Fiber pH Sensor Using a Sol-Gel Sensing Matrix 415 Luigi Rovati, Paola Fabbri, Luca Ferrari and Francesco Pilati Chapter 18 Mechanical Property and Strain Transferring Mechanism in Optical Fiber Sensors 439 Dongsheng Li, Liang Ren and Hongnan Li Chapter 19 High-Sensitivity Detection of Bioluminescence at an Optical Fiber End for an ATP Sensor 459 Masataka Iinuma, Yasuyuki Ushio, Akio Kuroda and Yutaka Kadoya Chapter 20 Fiber Optics for Thermometry in Hyperthermia Therapy 475 Mario Francisco Jesús Cepeda Rubio, Arturo Vera Hernández and Lorenzo Leija Salas Contents VII Chapter 21 White Light Sensing Systems for High Voltage Measuring Using Electro-Optical Modulators as Sensor and Recover Interferometers 491 Josemir C. Santos, José C. J. Almeida and Luiz P. C. Silva  Preface  Fiber optic is made of a plastic or glass core surrounded by cladding material. The difference in reflective index between these two components allows light to be guided inside the core with the principle of total internal reflection. The optical fiber and opto- electronics technologies are progressing rapidly due to innovations in telecommunications, semiconductor and consumer electronics sectors. The revolution in communication industries significantly reduces the prices of optical components and stimulates the development of optical fiber sensors. These sensors use optical fiber either as the sensing element ("intrinsic sensors"), or as a means of relaying signals from a remote sensor to the signal processor ("extrinsic sensors"). In the future, it is expected that optical fiber sensors will replace most of the conventional devices for the measurement of various physical, chemical and biological parameters such as temperature, pressure, strain, position, rotation, acceleration, electric, magnetic fields, acoustics, vibration, strain, humidity, viscosity, PH, glucose, gases, pollutants and many more. The field of optical fiber sensors is expected to expand and develop, influenced by new applications of the latest technologies. In this way, the subject continuous to mature and reach into new areas of engineering. This book reviews the recent topics on optical fiber sensors. Chapter 1 presents an overview of fiber optic sensors and their applications. The chapter discusses a review based on rare-earth doped fiber and new materials such as conducting polymer. Chapter 2 focuses on optical fiber sensors for volatile organic compound (VOC) detection. Fiber Bragg grating (FBG) and distributed Brillouin fiber sensors are the most popular sensing techniques for structural health detection. Recent progress in the use of these distributed sensors for structural health monitoring in energy infrastructures in China are discussed in Chapter 3. Chapter 4 presents an overview of intrinsic optical fiber sensors. Chapter 5 discusses a theoretical analysis and characterization of Brillouin gratings in optical fibers. Two applications of Brillouin grating are also given in this chapter. The first application is for the distributed birefringence measurement in polarisation maintaining fiber (PMF), and the second is for simultaneous measurement of temperature and strain. Chapter 6 reviews the principle of two frequency symmetrical radiation (TFSR) synthesis and its applications in fiber optic structural monitoring. A variety of TFSR multiplexed sensing functions can be provided by the TFSR technique. In this chapter, X Preface various sensor systems are also introduced based on optical reflectometry, distributed lateral stress location, multiplexed FBG and Fabry-Perot interferometer. Chapter 7 presents a thorough theoretical study of the optical fiber evanescent field sensors. A new method to estimate the sensitivity of the sensor is then proposed and verified experimentally. Chapter 8 presents a theoretical study of tapered optical fibers (TOFs) of different forms. The description starts with the rigorous analytical approach for conventional dielectric TOFs, and ends with the dispersion features as well as the relative power distribution for different low-order modes. The results are compared with those of conventional optical fibers in terms of dispersion characteristics, and it is found that the normalized frequency parameter is reduced for the TOFs. A microcsphere coupling system is presented in Chapter 9. The main aim of this chapter is to demonstrate the practical thermal sensing application based on the robust fiber- integrated microsphere coupling structure. Chapter 10 investigates the optical effects connected with coherent, polarized light propagation through a step-index fiber. The use of long period fiber gratings (LPFGs) as sensors is thoroughly explained in chapters 11 to 13. Chapter 11 reviews the fabrication methods, the theory behind the operation and applications of LPFGs. The application of LPFG produced by arc discharges in temperature and curvature sensors is explained in Chapter 12. Chapter 13 focuses on the possible application of long-period gratings technology in environmental monitoring, particularly in the measurement of surrounding refractive index or salinity. Chapter 14 provides an overview of the state-of-the-art, birefringence concepts, and new developments of high-birefringence fiber loop mirror configurations that can be used as sensing elements. Recently, plastic optical fiber sensors represent an emerging alternative for various applications in engineering. Chapters 15 to 17 present the development of plastic optical fiber-based sensors, which offer many unique features that could be exploited to achieve cost-effective sensing systems. The performance of various fiber optic displacement sensors is investigated theoretically and experimentally in Chapter 15. Chapter 16 presents the potential of POF sensing technique as an attractive option for various applications in civil engineering such as for monitoring strain, deflection, liquid level, vibration and detection of cracks. Chapter 17 demonstrates a facile method to develop POF pH sensors with a tip-based sensing element prepared by a sol-gel process, and consisting of phenol red indicator entrapped in a polymer-silica organic-inorganic hybrid material. Chapter 18 discusses the mechanical property and strain transferring mechanism of optical fiber sensors. Chapter 19 describes the construction of the optical fiber based system for efficient detection of bioluminescence at the optical fiber end. The sensitivity of Adenosine triphosphate (ATP) detection is investigated by using an avalanche photon diode (APD). ATP is a reliable indicator of biochemical reaction or life activity, since ATP is considered to be the universal currency of biological energy for all living things. Chapter 20 demonstrates fiber optic thermometers for hyperthermia therapy. This optical technique is normally used when electrical insulation and electromagnetic [...]... of optical -fiber devices encompasses optical amplifiers (Erbium Doped Fiber Amplifiers, EDFAs), fiber lasers, and optical fiber sensors 3 Optical fiber sensors Currently, the research and development of fiber- optic sensor devices has extended their applications to diverse technological fields, including the medical, chemical, and 4 Fiber Optic Sensors telecommunications industries Optical fiber sensors. .. are discussed as potential optical 2 Fiber Optic Sensors sensors because of their interesting electrical, chemical, and optical properties The final section provides the conclusions of the chapter The chapter ends with a bibliography on the topic that offers the reader an extensive selection of scientific references on optical fiber sensors 2 Optical fiber basics The optical fiber has represented a revolution... video and data Erbium-doped fibers can be used as optical amplifiers to extend the distance of transmission The investigations in this field have permitted the expansion of the spectrum of applications of optical fibers, leading to the development of new devices, such as fiber lasers and optical fiber sensors, which are the subject of this chapter An optical fiber is an optical waveguide in the shape... fiber by reflection or scattering and then guided back to the detection system (see Fig 4b) Fiber optic Optical source Photodetector a) Intrinsic sensor Fiber optic Optical source Photodetector b) Extrinsic sensor Fig 4 Arrangements of an optical fiber sensor: a) intrinsic and b) extrinsic sensor Optical fiber sensors, whether intrinsic or extrinsic, operate by the modulation of one (or more) of the... lightemitting diode (LED) as the optical source instead of a laser diode Therefore, the feasibility of employing polyaniline polymers in the development of intrinsic optical fiber sensors for the remote optical detection of ammonia was shown The development and commercialization of optical fiber sensors has increased in recent years The area of application of optical fiber sensors is now well identified,... configurations used in optical sensors: the Mach-Zehnder, Michelson, Fabry-Perot, and Sagnac The Mach-Zehnder interferometer configuration is the most widely used for acoustic sensing Phase-modulated sensors are much more accurate than intensity-modulated sensors Generally, fiber optic sensors can be conveniently classified according to the manner in which the optical fiber is used These sensors can then... intrinsic and extrinsic sensors Intrinsic fiber- optic sensor: These sensors directly employ an optical fiber as the sensitive material (sensor head) and also as the medium to transport the optical signal with information of the perturbation environment to be measured They operate through the direct modulation of the light guided into the optical fiber The light does not leave the fiber, except at the... an overview of fiber optic sensors and their applications It also describes new optical materials that are being investigated for the development of chemical optical sensors The chapter is organized into five sections (including conclusions) to provide a clear and logical sequence of topics The first section briefly reviews optical fiber fundamentals, including basic concepts, optical fiber structure,... advantages of this optical technique include its insensitivity to the intensity variations of the optical source signal, which helps to avoid errors in measurements; the simple detection system of the signal with the corrosion information; and the possibility of developing a fiber optic sensor to carry out measurements of corrosion in situ 8 Fiber Optic Sensors 4 Rare-earth-doped optical fiber sensors A rare-earth-doped... the optical power of transmittance for the optical detection of ammonia with PANI films Generally, optic sensors that are based on change in intensity are susceptible to the variation of the optical signal of the source, causing errors in the measurement Thus, the authors proposed the use of the optical power ratio technique to carry out the remote optical detection of ammonia 18 Fiber Optic Sensors . Photodetector b) Extrinsic sensor. Fiber optic Fiber Optic Sensors 8 4. Rare-earth-doped optical fiber sensors A rare-earth-doped optical fiber (laser fiber) undergoes the processes of. amplifiers (Erbium Doped Fiber Amplifiers, EDFAs), fiber lasers, and optical fiber sensors. 3. Optical fiber sensors Currently, the research and development of fiber- optic sensor devices has. via the optical fiber. The sensors that are based on reflection employ two bundles Optical Fiber Sensors: An Overview 5 Fig. 3. Basic components of an optical fiber sensor. of fibers