Polymer Optical Fibres

Fibre Types, Materials, Fabrication, Characterisation and Applications

Christian-Alexander Bunge, Markus Beckers, Thomas Gries

• Publisher: Woodhead Publishing
• Year: 2016
• ISBN:
  9780081000564
• Topic: Technology & Engineering
• Subtopic: Materials Science
• Index: Technology & Engineering

Polymer Optical Fibres: Fibre Types, Materials, Fabrication, Characterization, and Applications explores polymer optical fibers, specifically their materials, fabrication, characterization, measurement techniques, and applications. Optical effects, including light propagation, degrading effects of attenuation, scattering, and dispersion, are explained. Other important parameters like mechanical strength, operating temperatures, and processability are also described. Polymer optical fibers (POF) have a number of advantages over glass fibers, such as low cost, flexibility, low weight, electromagnetic immunity, good bandwidth, simple installation, and mechanical stability.

• Provides systematic and comprehensive coverage of materials, fabrication, properties, measurement techniques, and applications of POF
• Focuses on industry needs in communication, illumination and sensors, the automotive industry, and medical and biotechnology
• Features input from leading experts in POF technology, with experience spanning optoelectronics, polymer, and textiles
• Explains optical effects, including light propagation, degrading effects of attenuation, scattering, and dispersion

1

Introduction – why we made this book

C.-A. Bunge¹, M. Beckers², and T. Gries^{2 1}Hochschule für Telekommunikation Leipzig, Leipzig, Germany ²Institut für Textiltechnik at RWTH Aachen University, Aachen, Germany

Abstract

This chapter gives an introduction to the book. Starting with a brief history of communication and optical communication in particular the background is prepared for the rapidly developing techniques in polymer-optical fibres. We conclude the chapter with a list of the chapters to come and the motivation behind each of them.

Keywords

Communication; Data transmission; Glass optical fibres; Lighting; Polymer-optical fibres; Textiles

In this chapter we would like to explain the idea behind the book and why we spent so many hours on a new book about polymer-optical fibres. We start with a short overview on the historical background on optical communication and optical fibres in order to express the unbelievable momentum and speed of the development.

1.1. Historical background

Optical communication has a long tradition and history, which is older than the modern language. The first types of communication were hand signs, wave and fire. Even 350,000 BC, the Peking people used smoke signals for communication [1], a technique that is still in use in the Vatican to inform about the outcome of the pope elections. In Agamemnon, a tragedy composed by the Greek poet Aeschylus in 458 BC, the fall of Troy was communicated to Clytemnestra, Agamemnon's wife, via fire signs over the Greek mountains. Hereby, a distance of 500 km was bridged. In the modern age, Claude Chappe developed the first optical telegraph in France in 1791, the so-called Télégraphe Chappe [2]. Until the middle of the 19th century, this technology was widely established in Europe, but at the beginning of the 1840s, electrical telegraphy became dominant. Alexander Graham Bell, the inventor of the first marketable telephone, developed an optical communication device in 1880, which he called photophone. In this device, audio signals of speech are modulated onto a light wave, transmitted via optical lenses and re-converted into an acoustical signal via selenium cells [3]. However, the groundbreaking and most revolutionary invention in modern communication in general was the radio telegraph, which relied on low-frequency radio waves, developed by Guglielmo Marconi in 1896 [4,5]. Although radio technology is still used today, optical communication systems have become the most important technology for high-speed transport of great amounts of data, which would not be possible via radio waves to such an extent. In the second half of the 20th century, great advantages were made in optical fibre communication technology. Especially in the 1960s, the development of modern glass fibres and polymer-optical fibres started simultaneously.

1.1.1. Development of optical communication

The idea to use glass for applications with light is older than the physics of light itself. In the ancient civilisations of Egypt and Mesopotamia, transparent glass was sculpted into miniature heads. Working with glass was well-known in the ancient and medieval ages, when the glass workers of these ages saw that light could be guided by glass. However, all attempts at understanding failed, and physical explanations were missing; only in the 17th century Willebrord van Roijen Snell and Christiaan Huygens described the laws of refraction and the principles of light propagation for the first time [6]. After the physical basics of light had been understood, first experiments with light-guiding media were undertaken in the first half of the 19th century. Independently from each other, Daniel Colladon in Geneva and Jacques Babinet in Paris introduced light into a water jet with the consequence that the water began to lighten. Babinet performed further experiments with light in bent glass rods [7]. In 1852, John Tyndall repeated the experiments of Babinet and Colladon for his public lectures [8]. The idea of lighting water was furthermore used at the Universal Exposition 1889 in Paris in order to underline the finishing of the Eiffel tower with spectacular illuminated fountains [9].

The idea of lighting glass rods was of great research interest in the second half of the 19th century due to the fact that dentists needed light-guiding technologies in order to illuminate the whole mouth or other medical applications of endoscopes. William Wheeler from Indianapolis, United States invented a dental illuminator and patented it in 1881 [10]. However, the developed technologies suffered from the fact that losses were huge. A great improvement was made in the 1950s as sole glass filaments, which were used until then, became the first modern optical fibre by being cladded with a second layer of lower-refractive index glass by Harold Horace Hopkins and Narinder Singh Kapany in 1954 [11]. The observations from these experiments were of great importance for the development of light-guiding fibres, especially for the gastroscopy, which was introduced to market in the late 1950s.

In 1965, Manfred Börner developed the first optical-data transmission system based on optical fibres at Telefunken Research Labs in Ulm/Germany, which was patented in 1966 [12]. Another revolution was the development of the first laser system by Theodore Maiman in 1960 [13]. Laser systems enabled the use of almost monochromatic and highly intense light pulses, which tolerated larger losses along the transmission line, while the light signal had still received enough power. With the invention of the laser, a whole new range of applications based on coherent light became possible. In the late 1960s, the research in light-guiding fibres divided into glass optical fibres and the then newly developed polymer-based optical fibres. In the last decades of the 20th and the beginning of the 21st century, the fabrication technology has significantly improved and the fibre losses decreased dramatically. However, the principal light-guiding principle has still not changed. Currently, optical communication is a technology that is so interwoven with everyday life that cannot be replaced.

1.1.2. Development of glass-optical fibres

As described in the previous section, the use of glass has a long history and was already known in ancient Egypt. During the era of Renaissance, the state of Venice was well-known for its fabrication of glass fibres. In the 18th century, Réné de Réaumur achieved a breakthrough in the fabrication of spun-glass fibres by rotating of a wheel through molten glass. Hereby, the molten glass stuck to the wheel, which led to threads of glass [8]. This technology was improved leading into the ability of the fabrication of weavable glass fibres. During the second industrialisation, the Owens-Illinois Glass Company in Newark/Ohio developed a technology for mass-production of glass fibres. In this approach, hot air is blown into molten glass leading to short threads of fibres, which immediately solidify. This technology enabled the fabrication of glass wool [9].

For the fabrication of ultra-thin glass optical fibres with lengths of several 100 metres and more as well as diameters far below 1 mm a novel fabrication process was developed in the 1960s; silicon dioxide was deposited onto the walls of a rotating reactor chamber via chemical vapour deposition (CVD) and afterwards drawn to fibres [9]. Furthermore, fibre draw towers exist that enable the fabrication of glass fibres by an extrusion technology similar to the melt-spinning process. We will now consider the last 50 years in the history of light-guiding fibre glass and motivate the enormous developments up to date.

As mentioned previously, the groundbreaking development towards glass fibre-based light guides was the development of the laser by Theodore Maiman in 1960 [13]. In 1916, Albert Einstein had already described the physical principle of stimulated emission [14] and Rudolf Ladenburg provided the experimental evidence in 1928 [15]. After the Second World War, a three-energy level system was developed to construct a device for the amplification of microwaves using the principle of stimulated emission. This device, called Maser, was developed in 1953 by James P. Gordon and Herbert Zeigler and can be considered as a laser that operates in the microwave frequency spectrum [16].

The development of monochromatic light sources with high intensity was the final motivation for the development of light-guiding and data-transmitting fibres. However, the available glass fibres at the beginning of the 1960s suffered from huge attenuation of more than 1 dB/m, which was too high for efficient long-haul optical-data communication. An attenuation of 1 dB/m has the consequence that after a distance of 20 m only 1% of the initial optical power remains. As solution of this problem, Charles K. Kao found out that chemical impurities were responsible for the high attenuation and optical communication was possible with glass optical fibres [17]. Consequently, the fabrication process had to be improved in order to achieve...

Table of contents

• Cover image
• Title page
• Table of Contents
• Related titles
• Copyright
• List of contributors
• Woodhead Publishing Series in Electronic and Optical Materials
• Foreword
• 1. Introduction – why we made this book
• 2. Basics of light guidance
• 3. Basic principles of optical fibres
• 4. Special fibres and components
• 5. Materials, chemical properties and analysis
• 6. Fabrication techniques for polymer optical fibres
• 7. Mechanical properties of polymer-optical fibres
• 8. Polymer-optical fibres for data transmission
• 9. Applications of polymer-optical fibres in sensor technology, lighting and further applications
• 10. Polymer-optical fibre (POF) integration into textile fabric structures
• 11. Overview of the POF market
• Index