**Chapter 8 137**

Whispering Gallery Modes for Accurate Characterization of Optical Fibers' Parameters *by Martina Delgado-Pinar, Xavier Roselló-Mechó, Emmanuel Rivera-Pérez, Antonio Díez, José Luis Cruz and Miguel V. Andrés*

Preface

I have been involved in the research field of fiber optics for more than 15 years by working in all fiber lasers, all-optical signal processing, etc. Therefore, and considering that the field of optical fibers is within my research area of expertise, I accepted the very kind invitation of the IntechOpen editorial house to edit a book in this special field. Today, it is a great honor and pleasure for me to introduce this new book: *Applications of Optical Fibers for Sensing*. This is my third collaboration as book editor with IntechOpen after the successful experiences of *Applications of Digital Signal Processing* (2011) and *Current Trends in Short- and Long-Period Fiber Gratings* (2012). I truly hope that this new book will also be successfully received by

In this book the reader will find a collection of chapters written by different experts around the world, covering the broad field of sensing of different parameters through optical fibers. The main goal of this book is to give an updated overview of

First, in Chapter 2, "Minimalist Approach for the Design of Microstructured Optical Fiber Sensors," J.H. Osório and C.M.B. Cordeiro from Brazil report on the utilization of capillary-like fibers of different kinds as platforms for the realization of sensing measurements. These authors show that external stimuli can alter fiber wall thickness and/or induce birefringence variations, which in turn allows its use as a pressure sensor, temperature sensor, or refractive index sensor. Next, in Chapter 3,

"Fiber Bragg Gratings as e-Health Enablers: An Overview for Gait Analysis Applications," M.F. Domingues et al. from Portugal and Spain report on the use of fiber Bragg gratings for gait analysis monitoring, i.e. the monitoring of plantar pressure, angle, and torsion, with the purpose of future integration in rehabilitation

In Chapter 4, "Distributed, Advanced Fiber Optic Sensors," S. Kher and M.K. Saxena from India report on several optical fiber sensing techniques such as Raman scattering and fiber Bragg gratings, to be applied especially in the context of nuclear plant monitoring. In Chapter 5, "Real-Time Particle Radiography by Means of Scintillating Fibers Tracker and Residual Range Detectors," D. Lo Presti et al. from Italy report in detail on the construction and characterization of a charged particle

In Chapter 6, "Review of Liquid-Filled Optical Fibre-Based Temperature Sensing," F. McGuinness et al. from Ireland review on the current state of the art in liquidfilled optical fibre temperature sensing, with the focus on high-resolution temperature sensing. In Chapter 7, "Optical Fibre Long-Period Grating Sensors Operating at and around the Phase Matching Turning Point," R.Y.-N. Wong et al. from Singapore and the United Kingdom report on the behavior and potential uses for fiber optic sensing of a very special type of very sensitive long-period fiber grating: those

the worldwide scientific community.

exoskeletons and for prosthetic control.

imaging system by using scintillating optical fibers.

working at (and around) the phase matching turning point.

the current research trends in this rapidly evolving field.
