FIBER OPTICS ILLUSTRATED DICTIONARY © 2003 by CRC Press LLC Advanced and Emerging Communications Technologies Series Series Editor-in-Chief: Saba Zamir The Telecommunications Illustrated Dictionary, Second Edition, Julie K. Petersen Handbook of Emerging Communications Technologies: The Next Decade, RafaelOsso ADSL: Standards, Implementation, and Architecture, Charles K. Summers Protocols for Secure Electronic Commerce, Mostafa Hashem Sherif Protocols for Secure eCommerce, Second Edition, Mostafa Hashem Sherif After the Y2K Fireworks: Business and Technology Strategies, Bhuvan Unhelkar Web-Based Systems and Network Management, Kornel Terplan Intranet Performance Management, Komel Terplan Multi-Domain Communication Management Systems, Alex Galis Fiber Optics Illustrated Dictionary, Julie K. Petersen © 2003 by CRC Press LLC IBER PTICS ILLUSTRATED DICTIONARY JULIE K. PETERSENC CRC PRESS Boca Raton London New York Washington, D.C. © 2003 by CRC Press LLC Library of Congress Cataloging-in-Publication Data Catalog record is available from the Library of Congress This book contains infonnation obtained from authentic and highly regarded sources. Reprinted material is quoted with Permission, and sources are indicated. A wide variety of references are listed. Reasonable efforts have been made to publish reliable data and infonnation, but the author and the publisher cannot assume responsibility for the validity of all materials or for the consequences of their use. Neither this book nor any part may be reproduced or transmitted in any fonn or by any means, electronic or mechanical, including photocopying, microfilming, and recording, or by any infonnation storage or retrieval system, without prior permission in writing from the publisher. The consent of CRC Press LLC does not extend to copying for general distribution, for promotion, for creating new works, or for resale. Specific permission must be obtained in writing from CRC Press LLC for such copying. Direct all inquiries to CRC Press LLC, 2000 N.W. Corporate Blvd., Boca Raton, Florida 33431. Trademark Notice: Product or corporate names may be trademarks or registered trademarks, and are used only for identification and explanation, without intent to infringe. Visit the CRC Press Web site at www.crcpress.com © 2003 by eRC Press LLC No claim to original U.S. Government works International Standard Book Number 0-8493-1349-X Printed in the United States of America 2 3 4 5 6 7 8 9 0 Printed on acid-free paper © 2003 by CRC Press LLC Preface About This Dictionary The reader might assume that the process of writing or using a fiber optics dictionary is dry and uninteresting, but that really isn't the case. Fiber optics is a vibrant field, not just in terms of its growth and increasing sophistication, but also in terms of the people, places, and details that make up this challenging and rewarding industry. Fiber optics isn't as specialized as many people assume, either. Fiber optics forms the heart of the telephone industry, the nervous system of the computer network industry, and the organs of many medical, dental, experimental, and satellite technologies. That's part of the reason why this diction- ary is so big. The Internet, the phone system, and wireless satellite systems are joined at the hip, with fiber optics landlines often supplemented by satellite links and vice versa. Fiber optics is attracting attention from many different sectors. In Spring 2001, over 35,000 people from a wide variety of backgrounds attended a major international fiber optics conference. In spite of the inevitable peaks and slowdowns in the commercialization of any new technology, interest from professionals is growing and there are now thousands of training and certification courses for people who want to design, install, operate, and maintain fiber optic systems. The Quest for Communication by Light The fiber optics industry is very recent; most of the significant developments have occurred in the last 60 years. The application of fiber to underlying telecommunications infrastructures became important in the 1980s and the use of fiber spread to consumer products and local area networks by the late 1990s. The history of fiber optics is based upon the efforts of many multitalented, tireless inventors, who traded social interactions for the thrill of discovery. These pioneers were passionate in their search for a way to communicate with light. Alexander Graham Bell was more excited about his Photophone, a light-based telephone, than almost anything he ever invented, even though it was a commercial failure. Bell recognized that he dido't have all the pieces of the puzzle to make it a viable technology and chose to move on, but that doesn't mean the Photophone was a bad idea; it justhappened to be about 80 years ahead of its time. The earliest pioneers recognized certain potentially ground-breaking properties of optical ma- terials but weren't quite sure what made them work and, hence, were unable to fully harness their power. For example, in the 1600s, Rasmus Bartholin thoroughly described the doubly refracting birefringent properties of Iceland spar, a type of transparent calcite, but wasn't able to work out the mathematics. Later, both Wollaston and Nicol recognized Iceland spar could be assembled into new forms of prisms with special properties for controlling light, but it took many generations before scientists like Thomas Young began to unravel the mathematics that made this material so uniquely useful and applied that knowledge to describing the wavelike properties of light. No sooner had scientists become comfortable with the idea of light behaving as waves when Max Planck set the stage, in 1900, for a particle theory of light and Einstein elaborated and applied the new ideas in quantum dynamics, leading to our current understanding of the photoelectric effect. With the com- ing of the transistor and solid-state electronics, it was just a matter of time before smaller, less ex- pensive fiber-based components could be constructed. While optical science was evolving, the fabrication of pure glass was advancing as well. Many optical technologies in communications originated in much the same way as tongue depressors and penlights - doctors and dentists began using them to peer down people's throats. Scientists have long suspected that glass and lighthad capabilities far greaterthan anything yet imagined, but theyweren't sure how to combine the two and still keep the signal within the lightguide. In terms of communications applications, this was a big road block. The idea of "bending" light isn't new; Colladon and Tyndall demonstrated it in the mid-1800s by directing light inside an arc of water. But the experiment remained an impractical curiosity until glass rods were shown to refract light in the same way. Even so, the phenomenon of refraction needed to be better understood before glass rods could be turned into effective fiber optic filaments. By the middle of the 20th century, a few innovative scientists began coating glass with other materials, following the lead of Nicol, who had bonded together two pieces of Iceland spar with Canada balsam to create the Nicol prism. The new prism took advantage of the lower refractive index of Canada balsam and the birefringent properties of Iceland spar to split a beam of light and direct one beam out the side while the other continued forward. When the characteristic oflight to © 2003 by CRC Press LLC refract off lower refractive index materials was fmally harnessed in the form of cladding, fiber op- tics became a practical reality. From that point on, the quest for ideal proportions, purer glass, and more powerful, controllable light sources spurred the industry onto the next level of evolution. In the 1950s, the development of lasers provided the essential energy source that finally launched the optical communications industry. With fiber optics now widely deployed, has it become just another ubiquitous technology, like telephone poles and automobiles? Perhaps in some ways this is true - cables for local area networks can be readily purchased on the Internet and optical couplers cost only a few dollars. But that doesn't mean the industry has reached its limits or that the technology is no longer dynamically evolving. Fiber-based networks are still in their infancy and the exploitation of the properties of light is still young and full of promise. In addition, there are many areas of interest in which problems of instal- lation and deployment are tackled in innovative ways. For example, the city ofHouston has signed an agreement to use ahigh-tech robot to navigate the city's sewers to connect hundreds of premises to the fiber optic broadband networks to complete the "last mile" between the populace and the fiber backbone. Fiber optics is also becoming important in the signage, lighting, and medical industries. Light- weight, inexpensive colored light-guides, side-emitting filaments, linelights, and pointlights all have exciting applications in architecture, interior design, industrial safety, marketing, fine arts, and crafts. Hobbyists are using fiber filaments to light scale models and train sets. Inventive developers have created fiber optic "fabric" in which the fiber optic filaments are bent to deliberately release light at the joints where the weft crosses over the warp. Doctors and dentists use fiber optics for imaging and surgery. Wherever light is needed, there's a possibility a fiber optic filament can provide it. Purpose ofthe Dictionary It is the aim of this book to fill a gap in the literature on fiber optics. There is only one signifi- cant fiber optics dictionary on the market and it was last published in 1998. Many advances have occurred since that time that deserve to be documented. There is also a need for atext priced within the range of university students and technicians taking their certification training. This dictionary can meet that need as well. Audience for the Dictionary The Fiber Optics Illustrated Dictionary is suitable for awide variety of beginning profession- als in fiber optics, as well as students and instructors. It will also be ofinterest to professionals in other fields who want to get a beginning to intennediate introduction to optical technologies. The book covers historical antecedents, network protocols for telephone and computer networks, satel- lite technologies, telephone terminology, basic physics concepts, and units of measure important in optics. It also explains many math and light-refracting concepts through a combination of words and pictures so that concepts that are hard to understand at first are explained in two ways. This book does not attempt to duplicate the information in the FOLDOC online dictionary or the Federal Standards documents. These dictionaries are readily available and searchable on the Internet and are well documented in Martin Weik's dictionary. Instead, the Fiber Optics Illustrated Dictionary takes a current and comprehensive look at the fiber optics field and the various applica- tions of fiber optics, rounds out the picture with some introductory physics and fusion splicing in- formation, and presents it in a form that is illustrated, cross-referenced, and enhanced by historical biogfaphies and URL addresses for major not-for-profit and educational sites on the Web. . I hope you enjoy using the book as much as I enjoyed preparing it (despite the long hours and endless search for accurate and often elusive information). I am indebted to the hard work and enthusiasm of the professionals at CRC who helped bring it to fruition, including Jerry Papke, who contributed the original concept, Chris Andreasen and the proofreading staff, who labored over many pages, and Jamie Sigal, Nora Konopka, and the folks in the production and marketing departments who all answered questions and moved the project along. Thanks also to Dawn Snider for her excellent interpretation of the cover. Julie K. Petersen © 2003 by CRC Press LLC About the Author Julie K. Petersen is atechnology consultant, author, educator, and outdoor enthusiast, and readily admits to being a technophile. Her whole house is wired with computer and video links, both inside and out, and there's rarely a day when she isn't configuring some new piece of equipment to broadcast over a wireless transceiver. Since TRS-80 computing days, she's been tweaking and fixing her own equipment and talks about configuring a wearable computer to interface directly with GPS data on the Internet. "The technology is already here; it'sjust amatter ofputting all the pieces together. What you do is take ahead-worn display that projects an image on your retina with a laser beam that is eye-safe; such systems already exist. Then you have a body-worn GPS sensor with an interface and wireless link to the Internet that goes through a geographical server. The server matches your GPS coordinates with Web sites that offer information on maps, restaurants, nearby movie theaters, libraries, schools, etc. You could have a profile online for your preferences, and the display would change as your location changes. The process would be transparent, like a third eye, similar to the navigational images a fighter pilot sees projected over the landscape on the jet'stransparent canopy, except even more natural. I've named it the G-Eye™ for geographic eye or GPS eye. The image projected on the user's retina by the G-Eye system would be tailor-made to the ·viewer's preferences. It doesn't have to be a one-way communication either. If the wearer were a professional on the job, like a newscaster or research scientist, he or she could be wearing sensors with fiber optic faceplates to sense body changes or changes in the surrounding environment, pressure, temperature, light levels, etc., that could be fed back to the computer network to act as a hands-free 'body interface' or a roving human sensing system. The possibilities are endless. Some people may see this as far-fetched, the idea of the human organism as a sort ofsensory node on a distributed network, but young people readily understand and adapt to concepts such as this, especially if the new technology promotes or enhances social interactions, which this obviously could. The G-Eye would have been impractical a few years ago. Compact diode lasers, sensors that could respond quickly, and high-bandwidth network links weren't yet sufficiently developed. The limited capacity of the network infrastructure would have made such a two-way system impractical, but the new broadband fiber optic networks have astonishing speed and capacity, enough to individually outstrip the current collective traffic on the Internet. It's feasible to imagine the entire human populace interconnected through a combination ofwired and wireless optical links and satellites. Now equip the G-Eye with an optional digital video cam and microphone and you have an integrated network and digital phone/videoconferencing system that travels with you, instead ofa half-dozen different, unconnected, bulky systems. If there are interruptions in the network radio link, then you could carry a length of fiber optic cable that jacks into the nearest cafe or network vending machine for a clean wired link. Fiber optic cables are lighter and more robust than most people realize. If there's an emergency, the problem of clogged airwaves (familiar to traditional cell phone users) could be alleviated by people having these pocket cables integrated with their G-Eye systems as a backup to wireless connections. There might even be an all-optical solution in certain circumstances. Imagine free-air optical transceivers mounted on buildings (like small satellite receiving dishes) that people jack into with optical modems, somewhat like a two-way infrared remote control. That way, if you're sitting in a park or at a sidewalk cafe, you could aim at a transceiver to maintain connectivity. People have a tendency to think in terms of single solutions when often the best solution is a variety of options. Why putjust forks in your cutlery drawer when there's room for knives and spoons as well? Unfortunately, I haven't had time to build the G-Eye system. The time demands ofwriting a comprehensive dictionary on the subject offiber optics, which changes even as it is documented, is considerable and my spare time is almost nonexistent, but I'm fascinated by the depth and breadth ofapplications people are developing for optical waveguides, faceplates, and sensors and I'm sure there are many more surprises in store." The author lives in the Pacific Northwest and enjoys reading, music, film, strategy games, and interesting cuisine. She advocates the use of technology to enhance the quality oflife and solve human problems and especially encourages scientists and engineers to apply technology in ways that help reduce rather than extend the work week. © 2003 by CRC Press LLC How to Use the Fiber Optics Illustrated Dictionary General Format There are two sections to this reference: (1) a main alphabetical body, with nu- meral entries following Z and (2) several appendices with various charts, an extended section on ArM, a quick lookup acronym dictionary, and a timeline of telecommunications inventions and technologies. Entries Dictionary entries follow a common format, with the term or phrase in bold- face, followed by its abbreviation or acronym, if applicable. Pronunciation is included in cases where it may not be obvious. Alternate names (e.g., William Thompsom, a.k.a. Lord Kelvin) are cross-referenced. The body of the entry is included next, with multiple definitions numbered if there are several mean- ings for a term. Finally, where appropriate, there are cross-references, RFC list- ings, and URLs included at the end, in that order. Abbreviations In many cases, the term and its abbreviation are described together so the reader doesn't have to look up abbreviated references to understand aparticular entry; for example, cathode-ray tube will oftenbe followed by (CRT) and Federal Com- munications Commission by (FCC) so the words and their commonly used ab- breviations become familiar to the reader. Web Addresses Web addresses based upon Uniform Resource Locators (URLs) are listed for nonprofit, not-for-profit, charitable, and educational institutions and, in a few rare instances, for commercial enterprises with particular relevance for telecom- munications or with substantial educational content on their Web sites. For the most part, commercial URLs are not included. If the address isn't listed, it can often be guessed (http://www.companyname.com/) or otherwise easily located through Web search engines listed in Appendix D. RFCs Request for Comments (RFC) documents are an integral part of the Internet, and extremely important in terms of documenting the format and evolution of Internet protocols and technologies. For this reason, RFC references are listed with many of the Internet-related references and can be found in numerous RFC repositories online. There is also a partial list of significant or interesting RFC documents listed according to category in Appendix F. Diagrams and charts Illustrations are included as close to the related defmition as was possible in the space provided. Extensive listings of the various ITU-T Series Recommenda- tions are included in almost every chapter because they are the standards upon which most Internet technologies, telecommunications standards, and commer- cial products are built. Charts are usually included on the same page as the re- lated definition or the one following. Bootstrap Protocol l-"*r1r-tP1tT1rWccTileiennttlTs's;;;~ ns of stori ng and pro- vid' ration information. BOOTP evolved in the ARPANET days to allow diskless client ma- chines, and other machines which Inight not kno\\' their own Internet addresses~ to discover the IP ad- dress~ the address of a server host, and the name of a file to be loaded into memory and executed. This is accolnpl1shed in nvo phases: address determina- tion and bootfile selection; and file transfer, typi- cally \vith TFTP. This has since evolved into Dy- namic Host Configuration Protocol (DHCP). See Address Resolution Protocol, Dynalnic Host Con- figuration Protocot Reverse Address Resolution ro oc ~ RFC 95 l. http://www.urlgoeshere.org/ term or ph rase definition abbreviation or acronym pronunciation cross-references Web address (URL) Request for Comments reference number © 2003 by CRC Press LLC Contents Alphabetical Listings 1 Numerals 1043 Appendices 1049 A. Fiber Optics Timeline 1050 B. Asynchronous Transfer Mode (ATM) . . . . . . . . . . . . . . 1052 C. lTU-T Series Recommendations. . . . . . . . . . . . . . . . . . . 1055 D. List of World Wide Web Search Engines 1056 E. List of Intemet Domain Name Extensions. . . . . . . . . . 1057 F. Short List of Request for Comments (RFC) . . . . . . . 1059 G. National Associations 1062 H. Dial Equivalents, Radio Alphabet, Morse Code, Metric PrefixesNalues. . . . . . . . . . . . . . . . . . . . . . . . . . . 1066 I. ASCII Character and Control Codes. . . . . . . . . . . . . . . . 1067 © 2003 by CRC Press LLC a. 1. symb. alpha, the first letter in the Greek alpha- bet. 2. symb. angular acceleration. 3. symb. angle, in geometry. Along with ~, often used in geometric dia- grams to designate the angle of incidence or refrac- tion or other angles associated with light paths. a 1. symb. acceleration. See Acceleration 2. symb. anode. See anode. 3. abbrev. area. 4. symb. atomic mass. 5. abbrev. atto See atto A 1. symb. acoustic velocity. See acoustic velocity. 2. symb. ampere. See ampere. 3. symb. gain. See gain. A& Al leads See AlAI. A& BNumbers 1. Designations for two of the wire- less communication service categories available through Inmarsat satellite relays. Inmarsat A&B ser- vices are commonly used for ship-to-shore commu- nications. The InmarsatA & B Numbers vary depend- ing upon the ship and the selected satellite, but in- clude voice, facsimile, and data lines. See Inmarsat for a chart of service categories. 2. In mobile radio systems in general, but especially cellular, the A Num- ber is a designation for the originating call point, sig- naling towards the network, and the B Number is the destination or answering point. A & B bit signaling In communications networks, control or status information about the communica- tions line itself may be interspersed with the data con- tent that is being transmitted through that line. This is a form of in-band signaling. A&Bbit signaling is a technique of inserting signal state information into particular bits at intervals in the data transmission, thus robbing a certain number of bits from the total transmission. For example, A bits are used in voice communications implemented over Tt superframe (SF) networks to indicate outbound call signaling, with B bits as mirrors to the A bits. Through bit rob- bing, the A and B signal bits are carried in each 6th and 12th frame, respectively, of each of the 24 T1 subchannels. The types of supervisory information contained in these signal bits is relevant to switched voice or switched data services, including ring, busy, off-hook, and on-hook states. In extended superframe (ESF), A, B, C, and D bits may be robbed from the 6th, 12th, 18th, and 24th frames. In some telephony systems, tone signaling is con- verted to A&B bit signaling for interoperability. There is a trade-off when bits are robbed. Since the available bits are not all used for data, the total throughput is less when measured over time. How- ever, for less demanding voice communications, for example, the difference in speed and quality of the signal is not subjectively apparent to the listener. Diagnostic Tt channel decoders typically show the A and B bit signaling status, along with other alann, frame loss, or error conditions. NewerTl systems based upon bipolar eight-zero sub- stitution (B8ZS) don't use this bit-robbing technique. SeeB8ZS. A battery 1. A low voltage battery historically used to provide current to filaments or cathode heaters in electron tubes, now commonly used for small electronic appliances such as cameras, calculators, pen lights, etc. See battery. 2. A historic nonrechargeable FCC-Designated Communications Frequency Blocks Block Blk. Size Frequency Paired Frequency Notes Date A Block 30 MHz 1850-1865 MHz 1930-1945 MHz MTA Broadband PCS 1994-1995 B Block 30 MHz 1870-1885 MHz 1950-1965 MHz MTA Broadband PCS 1994-1995 C Block 30 MHz 1895-1910 MHz 1975-1990 MHz BTA Broadband PCS 1995-1996 D Block 10 MHz 1865-1870 MHz 1945-1950 MHz BTA Broadband PCS 1996-1997 EBlock 10 MHz 1885-1890 MHz 1965-1970 MHz BTA Broadband PCS 1996-1997 F Block 10 MHz 1890-1895 MHz 1970-1975 MHz BTA Broadband PCS 1996-1997 1 © 2003 by CRC Press LLC . 18 7 0 -1 885 MHz 19 5 0 -1 965 MHz MTA Broadband PCS 19 9 4 -1 995 C Block 30 MHz 18 9 5 -1 910 MHz 19 7 5 -1 990 MHz BTA Broadband PCS 19 9 5 -1 996 D Block 10 MHz 18 6 5 -1 870 MHz 19 4 5 -1 950 MHz BTA Broadband PCS 19 9 6 -1 997 EBlock 10 MHz. Broadband PCS 19 9 6 -1 997 EBlock 10 MHz 18 8 5 -1 890 MHz 19 6 5 -1 970 MHz BTA Broadband PCS 19 9 6 -1 997 F Block 10 MHz 18 9 0 -1 895 MHz 19 7 0 -1 975 MHz BTA Broadband PCS 19 9 6 -1 997 1 © 2003 by CRC Press LLC . small electronic appliances such as cameras, calculators, pen lights, etc. See battery. 2. A historic nonrechargeable FCC-Designated Communications Frequency Blocks Block Blk. Size Frequency Paired Frequency Notes Date A Block 30 MHz 18 5 0 -1 865 MHz 19 3 0 -1 945 MHz MTA Broadband PCS 19 9 4 -1 995 B Block 30 MHz 18 7 0 -1 885