Description
Sensing has become a key enabling technology in many areas, from entertainment technology to health, transport, and many industrial technologies. In many such advanced applications where miniaturization, sensitivity, and remote measurement are vital, optical fiber–based sensing techniques can provide novel solutions. As a result of this, optical fiber sensing (OFS) technology is developed as a powerful and rich technology that is currently being implemented in a wide variety of applications [1,2].
Research works on OFS are started in the 1960s, but it is the development of modern lowloss optical fibers that has made a transition from the experimental stage to practical applications. Some of the first sensing experiments using low-loss optical fibers [3–6] were demonstrated during the early 1970s. The field of OFS has continued to progress and developed enormously since that time. For instance, distributed fiber-optic sensors have now been installed in bridges and dams to monitor the performance and structural damage of these facilities. Optical fiber sensors are used to monitor the conditions within oil wells and pipelines, railways, wings of airplanes, and wind turbines. Decades of research led to the development of accurate optical fiber measuring instruments, including gyroscopes, hydrophones, temperature probes, and chemical monitors. As the OFS field is complementary to optical communication, it has availed the benefit of advancements on optical fibers and optoelectronic instrumentation. Due to the rapid development of optical fiber communication systems, the cost of optical fiber sensor systems has also significantly reduced due to the commercially viable key components such as light sources and photo detectors.
It is anticipated that research on OFS technology still continues to grow, and the technology will become widespread. Several new types of fiber sensors are progressively emerging, and some of the fiber sensing technologies are in a mature state and has been commercially produced and used in different applications. As light wave technology is becoming the new enabling technology behind many advanced high-end applications, optical fiber sensors can play an integral part of those developments.
The aim of this chapter is to introduce the basic principles of OFS and to provide a brief overview of some of the different types of fiber sensors developed all through the years and also to form the base for the rest of the chapters in this book
CONTENTS
1.1 Introduction.
1.2 Optical Fiber Sensors
1.3 Measurement Capabilities and Advantages of Optical Fiber Sensors
1.3.1 Classification of Optical Fiber Sensors.
1.3.1.1 Intensity-Modulated Fiber-Optic Sensors.
1.3.1.2 Phase-Modulated Fiber-Optic Sensors
1.3.1.3 Spectrometric (Wavelength-Based) Fiber Sensors
1.3.1.4 Polarimetric Fiber Sensors
1.4 Recent Developments in Optical Fiber Sensing
1.5 Optical Fiber Sensor Instrumentation
1.6 Optical Fiber Sensors: Industry Applications and Market
1.7 Conclusion.
References