SELECTED TOPICS ON OPTICAL FIBER TECHNOLOGY Edited by Moh. Yasin, Sulaiman W. Harun and Hamzah Arof Selected Topics on Optical Fiber Technology 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. 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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 Selected Topics on Optical Fiber Technology, Edited by Moh. Yasin, Sulaiman W. Harun and Hamzah Arof p. cm. ISBN 978-953-51-0091-1 Contents Preface IX Part 1 Fiber Lasers 1 Chapter 1 Rare-Earth Doped Optical Fibers 3 Efraín Mejía-Beltrán Chapter 2 Fabrication of Large Core Yb 2 O 3 Doped Phase Separated Yttria-Alumino Silicate Nano-Particles Based Optical Fiber for Use as Fiber Laser 17 M. C. Paul, A. V. Kir’yanov, S. Bysakh, S. Das, M. Pal, S. K. Bhadra, M. S. Yoo, A. J. Boyland and J. K. Sahu Chapter 3 An Improved Method of Fabricating Rare Earth Doped Optical Fiber 73 Ranjan Sen and Anirban Dhar Chapter 4 Tailoring of the Local Environment of Active Ions in Rare-Earth- and Transition- Metal-Doped Optical Fibres, and Potential Applications 95 Bernard Dussardier, Wilfried Blanc and Pavel Peterka Chapter 5 Tunable Rare-Earth Doped Fiber Laser 121 Arturo A. Castillo-Guzman and Romeo Selvas-Aguilar Chapter 6 Design of High Performance and Low-Cost Single Longitudinal Mode Laser Module for DWDM Application 143 Huei-Min Yang Chapter 7 Generation of Few Cycle Femtosecond Pulses via Supercontinuum in a Gas-Filled Hollow-Core Fiber 171 Walid Tawfik Mohamed, Jungkwuen An and Dong Eon Kim Chapter 8 Evanescent-Wave Pumped and Gain Coupled Whispering-Gallery-Mode Fibre Laser 195 Xiao-Yun Pu, Yuan-Xian Zhang and Li Feng VI Contents Part 2 Medical, Imaging, Spectroscopy and Measurement Applications 227 Chapter 9 Optical Fiber Near Infrared Spectroscopy for Skin Moisture Measurement 229 Ahmad Fairuz Omar and Mohd Zubir MatJafri Chapter 10 Live Cells as Optical Fibers in the Vertebrate Retina 247 Andreas Reichenbach, Kristian Franze, Silke Agte, Stephan Junek, Antje Wurm, Jens Grosche, Alexej Savvinov, Jochen Guck and Serguei N. Skatchkov Chapter 11 New Window on Optical Brain Imaging; Medical Development, Simulations and Applications 271 Chemseddine Mansouri and Nasser H. Kashou Chapter 12 Novel Conductive and Transparent Optical Fiber Probe for Multifunctional Scanning Tunneling Microscopy 289 Guo Xinli and Fujita Daisuki Chapter 13 Applications of Optical Fibers to Spectroscopy: Detection of High Explosives and Other Threat Chemicals 311 Natalie Gaensbauer, Madeline Wrable-Rose, Gabriel Nieves-Colón, Migdalia Hidalgo-Santiago, Michael Ramírez, William Ortiz, Oliva M. Primera-Pedrozo, Yahn C. Pacheco-Londoño, Leonardo C. Pacheco-Londoño and Samuel P. Hernandez-Rivera Chapter 14 Phase-Shifting Point Diffraction Interferometer Having Two Point Light Sources of Single-Mode Optical Fibers 355 Oshikane Yasushi, Nakano Motohiro and Inoue Haruyuki Part 3 New Optical Fibers 423 Chapter 15 “Crystalline” Plastic Optical Fiber with Excellent Heat-Resistant Property 425 Atsuhiro Fujimori Chapter 16 Design and Characterization of Single-Mode Microstructured Fibers with Improved Bend Performance 447 Vladimir Demidov, Konstantin Dukel’skii and Victor Shevandin Chapter 17 Fabrication and Applications of Microfiber 473 K. S. Lim, S. W. Harun, H. Arof and H. Ahmad Chapter 18 Influence of Current Pulse Shape on Directly Modulated Systems Using Positive and Negative Dispersion Fibers 509 Paloma R. Horche and Carmina del Río Campos Contents VII Part 4 Sensors 535 Chapter 19 Mechanical Properties of Optical Fibers 537 Paulo Antunes, Fátima Domingues, Marco Granada and Paulo André Chapter 20 Fiber Fuse Propagation Behavior 551 Shin-ichi Todoroki Chapter 21 Radiation Induced by Charged Particles in Optical Fibers 571 Xavier Artru and Cédric Ray Chapter 22 Non Linear Optic in Fiber Bragg Grating 587 Toto Saktioto and Jalil Ali Chapter 23 Optical Fibers and Optical Fiber Sensors Used in Radiation Monitoring 607 Dan Sporea, Adelina Sporea, Sinead O’Keeffe, Denis McCarthy and Elfed Lewis Chapter 24 Nanoparticles On A String – Fiber Probes as "Invisible" Positioners for Nanostructures 653 Phillip Olk Preface Optical fibers, an important and promising material, have been the subject of intensive research and development due to their many scientific and practical applications. They are designed to guide light along its length by confining as much light as possible in its core. The interaction between the propagating light with the fiber material is the foundation of the development of various applications such as optical amplifiers, fiber lasers, sensors etc. The use and demand for optical fibers have grown in tandem with numerous new applications that have been continuously introduced by researchers and engineers. The development of optical fiber technology for communication networks, medical applications and other areas represents a unique confluence of the physics, electronics and mechanical engineering disciplines. This new book presents the latest researches in the field optical fiber technology, which consists of four sections. Many current research efforts are focused on comprehending the theories, operating characteristics and technology of fiber laser and amplifier devices, which are mainly based on rare-earth-doped silica, as newfound technologies are expected to have profound impacts on a broad variety of communication and industrial applications. Section 1 presents the recent advances on fiber laser researches. The role of rare-earth optical fibers in fiber laser development is highlighted in Chapter 1. Chapters 2 and 3 describe the fabrication technique of rare-earth doped fibers using a modified chemical vapor deposition (MCVD) in conjunction with solution doping processes. Chapter 4 reviews on various efforts to comprehend and improve the spectroscopic properties of some rare-earth and thulium ions doped into silica. Chapter 5 demonstrates tunable fiber laser systems based on multimode interference effect. Chapter 6 describes microlens based fiber grating external cavity laser modules with low cost and good performance. Chapter 7 presents a review on the generation of few-cycle fs light pulses using gas-filled hollow-core fiber. Chapter 8 demonstrates a novel whispering– gallery–mode (WGM) fiber laser. The properties of the fiber laser, including energy threshold, produced length and polarization of lasing emission are discussed. Two important applications of the fiber lasers on optoelectronics, linearly polarized three- color lasing emission and single WGM lasing emission, are also demonstrated in this chapter. Section 2 reviews the applications of optical fibers to medical, imaging, spectroscopy and measurement. Chapter 9 discusses the development of near infrared spectroscopy X Preface system based on optical fiber for skin moisture measurement. Chapter 10 investigates the presence of cellular optical fibers in the retina. Chapter 11 gives a technical review of near-infrared light and systems, which are applicable to optical brain imaging. Besides for medical purpose, optical fiber imaging can also be used in spectroscopy and other applications. Chapter 12 introduces a novel optical fiber application in the form of conductive and transparent optical fiber probe in multifunctional scanning tunneling microscropy. This kind of probe can be utilized for high-quality scanning tunneling microscope (STM) imaging, near-field excitation and detection of high- intensity STM-induced electroluminescence (STML). Chapter 13 describes the applications of coupling optical fibers to spectroscopic instrumentation for applications in chemical and biological threats, and explosives detection. Chapter 14 presents a research work on point diffraction interferometry (PDI) and phase shifting (PS) method. The development of PS/PDI having two point sources of optical fibers for absolute surface figure measurement of large apertured optics is demonstrated. In this work, attempts are made to eliminate the inevitable wavefront distortion via numerical reconstruction of the wave based on inverse problem. Highly precise measurements of spherical and spherical mirrors are realized. Recently, several types of new fibers are developed for various applications. Section 3 reports on research advances on these fibers. Chapter 15 describes a newly developed “crystalline” plastic optical fiber with excellent heat resistance and dimensional stability. In this chapter, changes in the fine structure and lamella arrangement of the fibers formed by tetrafluoroethylene copolymers upon drawing are investigated by using wide-angle X-ray diffraction (WAXD) and small-angle X-ray scattering (SAXS) methods. This study is valuable as a fundamental research in the field of polymer physics. Chapter 16 demonstrates a single mode microstructured optical fiber (MOF) with improved bend performance. This chapter describes on research efforts on the finding and implementation of a few novel MOF designs that could effectively combine the large core dimensions and the expanded spectral operation range as compared to classical MOFs. It is obvious that new structures should be actualized by applying principles different from the basic concepts of the standard MOF technology. Chapter 17 thoroughly describes the fabrication of microfibers and its structures such as microfiber loop resonator (MLR), microfiber coil resonator (MCR) and microfiber knot resonator (MKR). A variety of applications of these structures will also be presented in this chapter. Chapter 18 discusses and compares how the shape of the modulated signal (e.g, exponential-wave, sine-wave, Gaussian, etc.) can improve the system performance when using both positive and negative dispersion fibers. With this method it is possible to improve each of the WDM system channels individually, offering a low-cost solution since it only involves changes in the transmitters and avoids replacing the fiber. This chapter also presents analytical and simulation results pertaining to the transmission of chirped optical signals in a dispersive fiber. Current progress of optical fiber sensors is reviewed in section 4. Chapter 19 describes the mechanical properties of commercial optical fibers such as the elastic constant, the [...]... some general considerations on the radiation–matter interaction, and continues with a review of irradiation effects on different types of optical fibers (silica optical fibers, plastic optical fibers, special optical fibers), effects which should be considered when developing radiation sensors The bulk of this chapter is dedicated to the designs of promising intrinsic and extrinsic optical fiber sensors... two-level fiber laser As introduced on section 2, three-level pumping amplifying systems may be studied as quasi two-level when absorption and emission spectra overlap Because these systems need to present population inversion all along the optical fiber, a serious level of pump power is not absorbed and hence emitted as residual This is a serious limitation of these systems concerning optical conversion... with the fiber lasers mentioned at the beginning of this section and presents good agreement with the experimental results 4 Other rare-earth fiber devices In this section, two relatively modern applications of REDF’s are described, both based on the upconversion phenomenon that is responsible of multi-photon absorption These Rare-Earth Doped Optical Fibers 19 devices depend on the development of special... all -fiber approaches consists on physically deforming an optical fiber to induce the losses It implies fiber fatigue and hence limitations in the life of the device Purely photonic approaches in which one beam of light controls another one have been recently demonstrated and have still several limitations such as non-transparency recovery Fig 10 (a) Energy levels involved in 700-750 nm attenuation by... Erbium-Doped Fiber Amplifiers: principles and applications (First Edition), Wiley-Interscience, ISBN 0-471-58977-2 , New York, USA Digonnet, M (2001) Rare-Earth-Doped Fiber Lasers and Amplifiers (Second Edition), Marcel Dekker, ISBN 0-8247-0458-4, New York, USA 22 Selected Topics on Optical Fiber Technology El-Agmi, RM Upconversion CW Laser at 284 nm in a Nd:YAG-Pumped Double-Cladding Thulium-Doped ZBLAN Fiber. .. population (N20) similar to E4 (N40) and as a consequence it is possible to obtain population inversion (N3>>N2) Under this condition, the spontaneously-emitted photons of energy E3-E2 propagate mostly through excited ions on E3 and because of resonance with E3E2, they become “negatively absorbed” by stimulating ions from E3 to make transitions to the practically empty E2 Negative absorption means... laser oscillation in an optical fiber based cavity.2 It consisted of a Nd3+-doped optical fiber cavity pumped by a flash lamp that for obvious reasons was termed fiber laser (FL) The fact that absorption losses in optical fibers were gradually decreasing (at present for example the best telecommunication fibers have a loss of less than 0.2 dB/km), together with the development of semiconductor lasers... modeling of optical sensors, and on the determination of aging performance of optical fiber deployed in telecommunication networks Chapter 20 briefly summarizes recent studies of macroscopic fiber fuse propagation behaviour in silica fibers The strong heat-induced absorption of silica glass and the highly confined supply of laser energy cause captured plasma to shift to the light source along the fiber leaving... stimulated emission in which one photon generates an identical one and hence optical amplification takes place because these two produce four, and so on The signal produced in this way and that amplifies through a long material such as an optical fiber is called amplified spontaneous emission (ASE) Also an external signal of energy E3-E2 becomes amplified as it propagates through the fiber, this is the... optimal fiber length for each pump power level (as studied in the next section) whereas in the four-level case, the fiber may exceed the required length One important advantage of three-level is: less fiber heating because there is only one step of non-radiative relaxation that implies an improvement of the conversion efficiency 2.4 Population dynamics of a three-level system Several amplifiers and fiber . general considerations on the radiation–matter interaction, and continues with a review of irradiation effects on different types of optical fibers (silica optical fibers, plastic optical fibers,. SELECTED TOPICS ON OPTICAL FIBER TECHNOLOGY Edited by Moh. Yasin, Sulaiman W. Harun and Hamzah Arof Selected Topics on Optical Fiber Technology Edited. cm. ISBN 978-953- 51- 00 91- 1 Contents Preface IX Part 1 Fiber Lasers 1 Chapter 1 Rare-Earth Doped Optical Fibers 3 Efraín Mejía-Beltrán Chapter 2 Fabrication of Large Core