`
`
`
`
`
`FIBER OPTICS
`
`STANDARD
`
`DICTIONARY
`
`THIRD EDITION
`
`- fiber optic filter - fiber optic flip-flop 0 fiber optic flood illumin
`5‘4A ,
`
`MARTIN H. WEIK
`
`
`
`
`
`
`
`1
`
`THOMAS SWAN 2004
`Finisar v. Thomas Swan
`|PR2014-00461
`
`1
`
`THOMAS SWAN 2004
`Finisar v. Thomas Swan
`IPR2014-00461
`
`

`

`
`
`JOIN US ON THE INTERNET
`
`WWW: http://www.th0mson.com
`EMAIL: findit@kiosk.thomson.com
`
`Ihomson.com is the on-line portal for the products, services and
`resources available from International Thomson Publishing (ITP).
`This Internet kiosk gives users immediate access to more than 34 ITP
`publishers and over 20,000 products. Through thomsoncom Internet
`users can search catalogs, examine subject—specificresource centers
`and subscribe to electronic discussion lists. You can purchase ITP
`products from your local bookseller, or directly through thomson.c0m.
`
`Visit Chapman & Hall’s Internet Resource Center for information on our new publications,
`links to useful sites on the World Wide Web and an opportunity to join our e—mail
`mailing list. Point your browser to: http://www.chaphall.com or
`
`http://www.th0mson.com/chaphall/elcctcng.html for Electrical Engineering
`
`
`
`
`
`
`
`2
`
`

`

`
`
`x DICTIONARY
`
`THIRD EDITION
`
`MARTIN H. WEIR
`
`V 34 ITP
`,nternet
`centers
`ie ITP
`011.com.
`
`lications ,
`c-mail
`
`aering
`
`
`
`E5
`
`CHAPMAN 51 HALL
`
`I® P9 International Thomson Publishing
`New York ' Albany 0 Bowl ' Huston ~ Cincinnati 0 Deu'oit ' London 0 Madrid 0 Melboume
`Mexico City I Pacific Grove ' Paris I San Francisco I Singapore ' Tokyo 0 Toronto ' Washingtuu
`
`
`
`
`
`
`
`
`
`3
`
`

`

`
`
`
`
`WWW: http://www.thomson.oom
`JOIN US ON THE INTERNET
`EMAIL: findit@kiosk.thomson.com
`thomson. com is the on»line portal for the products, services and resources available from
`International Thomson Publishing (ITP).
`This Internet kioslr gives users immediate access to more than 34 ITP publishers and over
`20,000 products. Through thomson.com Internet users can search catalogs, examine subject—
`speoifio resource centers and subscribe to electronic discussion listsl You can purchase ITP
`products from your local bookseller, or directly through thomson.com.
`Visit Chapman 8: Hall’s Internet Resource Center for information on our new publications, links to use—
`ful sites on the World Wide Web and an opportunity to join our e~mail mailing list. Point your
`
`browser to: http://www.chaphall.oom
`
`A service of I®P°
`
`Cover Design: Said Sayratiezadsh, Emdash Inc.
`Copyright © 1997 Chapman & Hall
`Printed in the United States of America
`For more information, contact:
`
`Chapman & Hall
`115 Fifth Avenue
`New York, NY 10003
`'
`Thomas Nelson Australia
`102 Dodds Street
`South Melbourne, 3205
`Victoria, Australia
`
`‘
`
`International Thomson Editorcs
`Campos Eliseos 385, Piso 7
`Col. Polanco
`11560 Mexico D‘F.
`Mexico
`International Thomson Publishing Asia
`221 Henderson Road #0510
`Henderson Building
`Singapore 0315
`
`Chapman & Hall
`2-6 Boundary Row
`London SE1 SHN
`England
`Chapman & Hall GmbH
`Fostfach 100 263
`‘
`D-69442 Weinheim
`Germany
`
`'
`
`International Thomson PublishingJapan
`Hirakawacho-cho Kyowa Building, 3F
`14.] Hirakawachu-cho
`Chiyoda-ku, 102 Tokyo
`Japan
`
`All rights reserved. No part of this work covered by the copyright hereon may be reproduced or used in any form or by any
`means—graphic, electronic, or mechanical, including photocopying, recording, taping, or information storage and rctn'eval
`systems—without the written permission of the publisher.
`12345678910XXX0100999897
`Library of Congress Cataloging-in-Publicntion Data
`Weik, Martin H.
`Fiber optics standard dictionary / Martin H Weik. ~ 3rd ed.
`p,
`cm.
`Includes bibliographical references.
`ISBN 0-41242241—3 (alk. paper)
`1, Optional communications—Dictionaries. 2. Fiber optics~
`Dictionaries.
`I. Title.
`TK5102.W45 1997
`621.36'92—dc21
`
`97-6013
`CIP
`British Library Cataloguing in Publication Data available
`
`“Fiber Optics Standard Dictionary, 3rd edition,” is intended to present technically accurate and authoritative information
`from highly regarded sources. The publisher, editors, authors, advisors and contributors have made every reasonable effort
`to ensure the accuracy of the information, but cannot assume responsibility for the accuracy of all information or for the con-
`sequences of its use.
`
`To order this or any other Chapman & Hall book, please contact International Thomson Publishing, 7625 Empire
`Drive, Florence, KY 41042. Phone: (606) 525-6600 or 1-800-842-3636.
`Fax: (606) 5254778, e-mail: order@chaphall.com.
`For a complete listing of Chapman & Hall’s titles, send your requests to
`Chapman & Hall, Dept. BC, 115 Fifth Avenue, New York, NY 10003.
`
`
`
`
`
`
`4
`
`

`

`
`
`W a
`
`rtificial intelligence
`
` 33
`
`See also database, database management system,
`data medium.
`
`area: See antenna effective area, blanketing area,
`blind area, broadcast area, cladding tolerance area,
`coherence area, controlled area, core area, core tol-
`erance area, exchange area, input area, local service
`area, maximum calling area, output area, restricted
`area, technical area, White area.
`
`area broadcast station: 1. A land station responsible
`for radio broadcasting to a specific geographical area,
`i.e., a broadcast area. of the Earth, such as a land station
`in a cellular telephone system. Note: Area broadcast
`stations may be interconnected with fiber optic nets. 2.
`A radio station responsible for broadcasting to one of
`the 12 numbered areas into which the world has been
`divided for operating the merchant ship broadcast sys-
`tem. See also broadcast,broadcast area, cellular tele-
`phone, fiber optic net, interconnection.
`area code: A telephone system number that has been
`assigned to a specific geographical area. See also ad-
`dress, code, telephone system.
`
`area network: See local area network, metropolitan
`area network, wide area network.
`
`area telephone service: See inward wide area tele-
`phone service, outward Wide area telephone service.
`argument: 1. An independent variable. 2. Any value
`‘of anindependent Variable. Note: Examples of argu»
`ments are search keys, numbers that identify the loca-
`tion of data in a table, and the G) in sin 6. See also
`key, variable.
`1
`arithmetic check: Synonym mathematical check.
`Armed Forces Radio Service: A radio broadcasting
`service that is operated by and for the personnel of the
`armed services in the area covered by the broadcast.
`Common abbreviation: AFRS. Noted : An example of
`an AFRS is the radio service operated by the US.
`Army for US. and allied military personnel on duty in
`overseas areas. Note 2: Signals to Armed Forces Radio
`Service broadcasting stations may be sent via fiber optic
`links. See also broadcast, broadcast area, fiber optic
`link, station.
`
`,
`
`armor: In a communications cable, such as a fiber
`Optic cable, a component that (a) protects the critical
`internal components, such as buffer tubes, optical fibers,
`0r electrical conductors, from damage from external
`environmental conditions, such as mechanical abuse,
`rodent attack, fish bite, and abrasion, (b) usually con-
`Sists of a steel or aluminum tape wrapped about an
`iliner jacket that covers the critical internal components,
`and (C) usually is govered by an outer jacket. Note:
`
`i
`
`i
`
`Armor usually is used on cables installed in harsh envi-
`ronments, such as beach and river crossing cables, ship-
`to-shore tethered cables, and aerial inserts. Sea also
`aerial insert, cable, component, conductor, fiber op-
`tic cable, jacket, optical fiber, overarmor, tethered
`cable.
`
`array: 1. An arrangement of elements in one or more
`, dimensions. 2. In a programming language, an aggre-
`gate that consists of data objects with identical attri-
`butes, each of which may be uniquely referenced. See
`antenna array, attribute, broadside antenna array,
`collinear antenna array, field programmable logic
`array, planar array, programmable logic array, sen-
`sor array, solar array, uniform linear array. See
`also matrix.
`
`
`
`arrester: A device that protects hardware, such as sys-
`tems, subsystems, circuits, and equipment, from voltage
`or current surges that may be produced by lightning or
`an electromagnetic pulse (EMF). Note: If the hardware
`is adequately protected, associated software may also be
`adequately protected. See also air terminal, current,
`electromagnetic pulse, hardware,
`lightning down
`conductor, lightning protection subsystém, protec-
`tor, voltage.
`
`arterial cable: In a fiber optic transmission system, a
`multifiber cable that is used in a trunk in a fiber optic
`net. See also fiber optic cable, fiber optic net, fiber
`optic transmission system, fiber optic trunk, multi-
`fiber cable.
`
`arteriovenous oximeter: See fiber optic arteriove-
`nous oximeter.
`g.
`
`articulation angle: See borescope articulation angle.
`articulation index: A measure of the intelligibility of
`voice signals. Note I .' The articulation index is usually
`expressed as a percentage of speech units that are under—
`stood by the listener when heard out of context. Note 2:
`The articulation index is affected by noise, interference,
`and distortion. See also distortion, intelligibility, in-
`terference, noise, optical signal, signal, voice intelli-
`gibility, voice service.
`artificial intelligence: Pertaining to equipment that per-
`forms functions that (a) are usually associated with
`human intelligence or (b) are similar to functions per—
`formed by humans, such as reasoning, learning, deci-
`sion making, and self—improvement. Common abbrevi-
`ation: AI. Note: Artificial intelligence is the branch
`of computer science that attempts to approximate the
`results of human reasoning by organizing and manipu-
`lating factual and heuristic knowledge. Areas of AI
`activity include expert systems, natural language under-
`
`
`
`mf—
`
`5
`
`

`

`
`
`601
`
`modulation
`
`metic operations, and (0) requires two to three times as
`maycombinational circuits as the conventional binary
`adder. Synonym Luca] code. See also code, combina-
`tional circuit, error detection, parity bit.
`
`modular: 1. Pertaining to the design concept in which
`interchangeable units are used to create an assembled
`functional unit. Note : Fiber optic transmission systems
`are primarily modular systems. Modules include fiber
`optic Couplers, fiber optic receivers, fiber optic repeat-
`ers, and fiber optic transmitters. 2. Pertaining to the
`composition of a system by means of assembled and
`interconnected modules, usually each of which can be
`individually replaced. See also fiber optic coupler,
`fiber optic receiver, fiber optic repeater, fiber optic
`transmitter, functional unit, module.
`modular decomposition: The designing of a system
`by (a) subdividing it into separate components or mod—
`ules, (b) designing each component or module sepa-
`rately with due consideration being given to the
`interfaces between them, and (c) interconnecting the
`components or modules. See also component, hierar-
`chical decomposition,
`interconnection,
`interface,
`module.
`
`.
`
`modularity: The extent to which a system or a func—
`tional unit is composed of discrete interconnected hard—
`ware or interrelated software components or modules,
`Note: An optimum level of modularity allows for im-
`proved installation, operation, testing, and maintenance
`flexibility. See also component, discrete, functional
`unit, hardware, interconnection, module, software.
`
`modular jack: A device that conforms to the Code of
`Federal Regulations, Title 47, part 68, that defines the
`size and configuration of all units that are permitted
`for connection to the public exchange facilities, i.e.,
`public switched network facilities. See also configura-
`tion, connection, exchange, public switched network.
`Modular Measurement Systcm: An industry standard
`that (a) is controlled by a consortium led by test and
`measurement (T&M) manufacturers, (b) is specially
`suited for microwave, radio frequency, and lightwave
`systems testing, and (0) allows tailored architectures
`of equipment for T&M. See also industry standard,
`lightwave, microwave, radio frequency, standard,
`test and measurement activity, test.
`modular spread spectrum code sequence generator:
`In spread spectrum systems, a spread spectrum code
`sequence generator in which each flip—flop in the code
`sequence register is followed by a modulo-two adder.
`See also code sequence generator, code sequence
`register, flip—flop, modular, module, modulo, spread
`
`spectrum, spread spectrum code sequence gen-
`erator,
`
`modulate: 1. To vary a characteristic or parameter of
`an entity in accordance with a characteristic or parame—
`ter of another entity, such as (a) to vary the irradiance,
`i.e., the intensity, of a beam from a light source, such
`as a laser, in accordance with an intelligence-bearing
`electronic signal applied to the source or (b) to vary
`the radiant power at a point in a waveguide, such as
`an optical fiber, in accordance with a physical variable
`being sensed or measured, such as in a microbend sen»
`sor or a Sagnac fiber optic sensor. 2. To vary any
`property, characteristic, or parameter of a wave, such
`as amplitude, phase, frequency, pulse position, or pulse
`duration, usually for the purpose of transferring infor-
`mation. Note 1 .' A wave can be modulated by superim-
`posing another wave or by varying a physical parameter
`to which the wave is sensitive, such as by varying
`attenuation in an optical fiber or controlling the output
`of a laser by varying the driving voltage. Note 2: Modu—
`lation in an uncontrolled or random manner creates
`noise or'interference. 3. To vary a characteristic of a
`carrier in accordance with an information-bearing sig-
`nal. See also amplitude, attenuation, beam, carrier,
`characteristic, demodulate, demodulation, entity,
`frequency, information-bearing signal, interference,
`irradiance, Kerr effect,
`laser, microbcnd sensor,
`modulation, noise, optical fiber, parameter, phase,
`pulse duration, pulse duration modulation, pulse
`position modulation, radiant power, Sagnac fiber
`optic sensor, signal, voltage, waveguide. Refer to Fig.
`1-1.
`
`modulated signal: The signal that results when a carrier
`is modulated by a signal, such as when a carrier is
`modulated by an infonnation—bearing signal. Note: Ex-
`amplcs of modulated signals are the signals that result
`when (a) a sine wave carrier is modulated by a baseband
`signal or (b) a continuous lightwave from a laser is
`modulated by an optical modulator. See baseband sig-
`nal, carrier,
`information-bearing signal,
`laser,
`lightwave, modulate, optical modulator, pulsed fre-
`quency modulated signal, signal, sine wave.
`modulating signal: The signal, such as an information—
`bearing signal, that is used to modulate a carrier. See
`also baseband signal, carrier, informatiombearing
`signal, modulated signal, modulation.
`modulation: 1. The controlled or uncontrolled varia-
`tion of a characteristic or parameter of an entity in
`accordance with a characteristic or parameter of another
`entity, such as (a) a controlled variation of any property
`of a wave for the purpose of transferring information
`or (b) the random fluctuation of a signal caused by a
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`6
`
`

`

`
`
`
`
`
`
`
`
`—‘fi—
`
`»modulation—demodulation linearity
`
`-
`
`lightning strike on a communications line. 2. In commu-
`nications systems, such as fiber optic transmission sys—
`tems, the process, or the result of the process, of varying
`a characteristic of a carrier in accordance with an infor»
`mation—bearing signal. 3. The controlled variation of a
`parameter, such as amplitude, phase, frequency, pulse
`position, or pulse duration, of a wave usually for the
`purpose of transferring information. Note I : Modula-
`tion can be accomplished by superimposing another
`wave or by varying a physical parameter to which the
`wave is sensitive, such as by varying attenuation in an
`optical fiber or controlling the output of a laser by
`varying the driving voltage. Note 2: Uncontrolled or
`random modulation is considered to be noise or interfer-
`ence. Note 3: Examples of modulation are (a) variation
`of the amplitudeor frequency of a carrier in accordance
`with an analog signal, such as a voice or video signal,
`(1)) variation ‘of the irradiance, i.e., the intensity, of
`a lightbeam from a light source, such as a laser, in
`accordance with an information~beanng electronic sig-
`nal applied to the source, and (c) variation of the radiant
`power at apoint in a waveguide, such as an optical fiber,
`in accordance with a physical variable being sensed or
`, measured, such as in a microbend sensor or. a Sagnac
`fiber optic sensor. See absorption modulation, abs
`sorptive modulation, adaptive differential pulse
`code modulation, amplitude modulation, analog in-
`tensity modulation, analog modulation, angle modu-
`lation, balanced amplitude modulation, balanced
`modulation, binary modulation, conditioned di-
`phase modulation, constant current modulation,
`continuously variable slope delta modulation, con-
`tinuous phase modulation, cross modulation, delta
`modulation, delta sigma modulation, demodulation,
`delay modulation, differential modulation, differen-
`tial pulse c'ode modulation, differential trellis coded
`modulation, digital frequency modulation, digital
`modulation, digital phase modulation, direct se-
`quence modulation, double modulation, electrooptic
`phase modulation, external optical modulation, final
`modulation, fixed reference modulation, frequency
`code modulation,
`frequency hopping direct se-
`quence modulation,
`frequency modulation,
`full
`modulation, incremental phase modulation, inten-
`sity modulation, intermodulation, isochronous mod-
`ulation, jammer modulation, jamming modulation,
`low-level modulation, mechanically induced modu-
`lation, multilevel modulation, nonreturn to zero
`(change) modulation, nonreturn to zero (change on
`ones) modulation, 100% modulation, percentage
`modulation, phase modulation, polarization modu-
`lation, pulse amplitude modulation, pulse code mod-
`ulation, pulse duration modulation, pulse interval
`modulation, pulse modulation, pulse position modu-
`
`602
`
`lution, pulse time modulation, quadrature amplitude
`modulation, quadrature modulation,
`reference
`modulation, start—stop modulation, subband adap-
`tive differential pulse code modulation, suppressed
`clock pulse duration modulation, synchronous de-
`modulation,
`telegraph modulation,
`trellis coded
`modulation, wavelength modulation. See also ampli-
`tude, carrier, demodulate, demodulation, frequency,
`information-bearing signal, irradiance, laser, light-
`beam, microbend sensor, modulate, optical fiber,
`phase, pulse duration, pulse position modulation,
`Sagnac fiber optic sensor, waveguide. Refer to Fig.
`M-2. Refer also to Figs. N—13, P-12. Refer to Appendix
`B, Tables 1, 2.
`modulation—demodulation linearity: A measure of
`the presence or absence of harmonics of the frequenCy
`of the modulating signal in the signal that results from
`the modulating or demodulating process, such as the
`electrical output signal of a fiber optic link or fiber
`optic loop. See also fiber optic link, fiber optic loop,
`harmonic,
`information-bearing signal, modulate,
`modulating signal, modulation, output, signal.
`modulation domain: 1. Pertaining to the spectrum of
`electronic and optical equipment that are devoted to
`measuring the characteristics of modulated waves. 2.
`The entire realm of modulation, including (a) the array
`of modulation equipment, such as modulators and de— '
`modulators, (b) the generation, transmission, and recep-
`tion of modulated waves, including radio waves, video
`signals, and lightwaves, and (c) the measurement of
`the characteristics and parameters of modulated Waves.
`See also demodulator, lightwave, modulate, modula-
`tion, modulator, parameter, radio wave, reception,
`transmission, video signal.
`modulation factor: 1. In amplitude modulation, the
`ratio of (a) the peak variation actually used, i.c,, the
`maximum peak-to—trough value that occurs in a given
`signal, such as an optical signal in an optical fiber, to
`(b) the maximum design variation, i.e., the maximum
`peak»to-trough value the system is designed to allow.
`Note: In conventional amplitude modulation (AM), the
`maximum design variation is considered to be that for
`which the instantaneous amplitude of the modulated
`signal reaches zero. When zero is reached, the modula—
`tion factor is 100%. 2. In an amplitude—modulated elec-
`tromagnetic wave, the ratio of (a) the difference be-
`tween the maximum amplitude and the minimum
`amplitude to (b) the maximum amplitude Note: As the
`modulation factor is increased to where the modulated
`signal value reaches zero, the modulation factor is unity,
`i.e., the modulation is 100%. Attempts at modulation
`beyond this point will result in signal distortion. 3. In
`a frequency—modulated electromagnetic wave, the ratio
`
`
`
`
`
`
`
`
`
`7
`
`

`

`
`
`
`
`
`
`
`
`spectrometer
`
`950
`
`tion rate, fiber optic link, fiber optic loop, infrared,
`local area network, network, optical spectrum,
`propagation medium, transmission, transmittance,
`wavelength.
`
`spectrometer: A spectroscope that (a) is equipped with
`an angle scale, 03) is used to measure the angular devia-
`tion of radiation of different wavelengths, and (c) is
`used to measure angles between surfaces of optical
`elements. See also optical element, radiation, spectro-
`scope, wavelength.
`
`spectroscope: An instrument that disperses radiation
`into its component wavelengths and allows observation
`or measurement of the wavelength composition of the
`resultant spectrum. See also dispersion, radiation,
`spectrum, wavelength.
`
`spectroscopy: The branch of science and technology
`devoted to (a) the study and'application of ways and
`means of making optical measurements, such as mea-
`suring optical wavelengths, spectral composition, and
`spectral distribution and (b) the performance of spectral
`analyses. See also optical wavelength, spectral analy-
`sis, spectral composition, spectral distribution, spec-
`trometer, spectroscope.
`.
`
`,
`
`spectrum: A continuous range or group of frequencies,
`or groups of ranges, of waves that have something in
`common, such as (a) all frequencies in a train of similar,
`equally spaced, rectangular pulses, (b) all the frequen-
`cies in a beam of visible light, (c) a band of radio
`frequencies (rf), (d) all the frequencies in a sound wave,
`such as a musical chord, and (e) all the frequencies that
`are visible. See continuous spectrum, direct sequence
`spread spectrum, electromagnetic frequency spec-
`trum, electromagnetic spectrum, frequency hopping
`spread spectrum, frequency spectrum, frequency
`spectrum designation, line spectrum, optical spec-
`trum, primary spectrum,
`secondary spectrum,
`spread spectrum, visible spectrum, visual spectrum:
`See also band, beam, characteristic frequency, fre-
`quency, light, line source, pulse, radio frequency,
`sound wave, wave. Refer to Figs. 0-6, 0-15. Refer
`also to Appendix B, Tables 1, 2.
`
`spectrum analysis: 1. An analysis that shows (a) the
`distribution of energy or energy density contained in a
`set of electromagnetic waves of more than one fre-
`quency as (b) a function of frequency. 2. An indication
`of all the frequency or Wavelength components in any
`wave, such as an electromagnetic wave, a sound wave,
`or a water wave. See also electromagnetic wave, fre-
`quency, signature analysis, sound wave, spectrum
`signature.
`
`spectrum analyzer: See electrical spectrum ana-
`lyzer, integrated optical spectrum analyzer, light-
`wave spectrum analyzer, optical spectrum analyzer.
`
`spectrum code sequence generator: See spread spec-
`trum code sequence generator.
`
`spectrum designation: See frequency spectrum des-
`ignution.
`
`spectrum designation of frequency: Synonym fre-
`quency spectrum designation.
`
`spectrum signature: 1. The frequencies that make up
`the waves emanating from a particular source, such
`as (a) the frequencies (or wavelengths) in lightwaves
`' emanating from a light-emitting diode (LED) and
`(b) the frequencies contained in a sound wave in water
`emanating from a given ship. 2. In a device, the pattern
`of radio signal frequencies, amplitudes, and phases, that
`(a) characterizes the output of the device, (b) tends to
`distinguish the device from otherdevices, and (c) may
`be used to identify the device. 3. In electronic equip~
`merit, a collection of the spectral characteristics of ema—
`nations, transmissions, or reflections from the equip-
`ment that are measured, calculated, or estimated. Note:
`Spectrum signatures may be obtained from any radia—
`tive equipment, such as radio and radar transmitters
`and receivers, antennas, and. direction finding (DF)
`equipment. Some of the electromagnetic characteristics
`that may be evident in a spectrum signature are band—
`width, power output, sensitivity, selectivity, modula~
`tion, spurious radiation and responses, interrnodulation,
`cross modulation, antenna beam pattern, and dynamic
`range. 4. The electromagnetic wave that is obtained as
`an echo from an object in space. Note: The waveshape
`contains information or evidence concerning the nature
`of the object, such as its size or shape. The echo may
`be analyzed into the amplitudes of its frequency compo-
`nents as a function of time and used to identify the
`nature or motion of the reflector when this information
`is coupled with information from other sources. See
`also bandwidth, cross modulation, frequency, inter-
`modulation, light-emitting diode, modulation, radio,
`receiver, selectivity, sensitivity, signal, signature
`analysis, spectral analysis, spectrum analysis, trans-
`mitter, wave, wavelength, waveshape.
`specular: Pertaining to the maintenance of uniformity
`in a wave that is subject to influence by material media,
`such as reflection and refraction. See also reflection,
`refraction, specular reflection, specular transmis-
`sion, wave.
`
`specular reflection: 1. Reflection from a smooth
`curved or planar surface, such as that of a mirror, a
`polished sheet of silver, or an optical fiber endface, so
`
`
`
`
`
`
`
`8
`
`

`

`
`
`
`
`951
`
`there is negligible diffusion as Sncll’s laws of
`that
`reflection and refraction are microscopically obeyed
`over a uniformly directed real surface. Note 1 .' Specular
`reflection results in clear and sharp images, such as are
`obtained from plane, concave, or convex high—grade
`mirrors. Note 2 .' Specular reflection enables the obtain-
`ing of a clear image of the source of radiation, Note
`3: Coherence can be maintained during specular refiec~
`tion. 2. Reflection from a smooth surface, such as a
`mirror, so that a clear image of the source, such as a light
`source or light reflected from an illuminated object, can
`be formed on a transverse virtual or real surface, such
`as that of the focal plane of a lens, a screen, or the
`retina of the eye, but a clear image of the reflecting
`real surface cannot be obtained. Synonyms regular re-
`flection, spectral reflection. See also coherence, con-
`cave, convex, diffuse refiection, focal plane, illumi-
`nate, illumination, image, lens, light source, mirror,
`object, optical fiber endface, radiation, real surface,
`reflection, refraction, Snell’s law.
`
`specular transmission: The propagation of lightwaves
`in a propagation medium such that (a) diffusion attenua~
`tion is negligible, (b) smooth changes in refractive indi—
`ces result in the refraction of rays at the microscopic
`level, and (c) in aligned bundles, clear images are pre-
`served during propagation. Note: Specular transmission
`results in improved performance of optical waveguides,
`such as optical fibers, aligned bundles, and fiber optic
`cables. Synonym regular
`transmission. See also
`aligned bundle, diffusion, fiber optic cable, light-
`wave, optical fiber, optical waveguide, propagation,
`propagation medium, ray, refractive index, trans-
`, mission.
`speech: See coded speech, plain speech.
`
`speech analyzer: A device that consists of electronic
`circuits or optical circuits that convert analog speech
`waveforms into narrowband digital signals which then .
`can be transmitted, stored, or analyzed to determine the
`frequency distribution in the voiced signals for compari-
`son with other voiced signals. See also analog, circuit,
`digital signal, frequency, narrowband, optical cir-
`cuit, signal, voice coder, waveform.
`speech digit signaling: Signaling (a) in which digit
`time slots primarily used for coded speech are used for
`signaling and (b) that is an option in networks based
`on the Integrated Services Digital Network (ISDN).
`Note: Speech digit signaling may be accomplished with
`optical signals in fiber optic cables. See also coded
`speech, Integrated Services Digital Network, fiber
`optic cable, network, optical signal, signaling, time
`slot.
`
`speech scrambling
`
`speech interpolation: See analog speech interpola-
`tion, digital speech interpolation.
`
`speech plus: Pertaining to circuits, including electronic
`and fiber optic circuits, that were designed and used
`for speech transmission, but to which other uses, such
`as digital data transmission, facsimile transmission,
`telegraph transmission, or signaling superimposed on
`the speech signals, have been added by means of multi-
`plexing. See also circuit, facsimile, fiber optic circuit,
`fiber optic link, multiplexing, signaling, telegraph,
`transmission.
`
`speech plus duplex operation: Operation in which
`(a) speech and telegraphy, duplex or simplex, are trans»
`mitted simultaneously over the same circuit, such as a
`fiber optic circuit or an electronic circuit, (b) mutual
`interference is eliminated by the use of filters, and
`(c) the circuits are usually used for the transmission
`of voice signals. See also circuit, composite circuit,
`duplex, duplex operation, fiber optic circuit, fiber
`optic link, filter, interference, mutual interference,
`signal, simplex, telegraph, transmission, voice.
`speech plus signaling: Pertaining to equipment, includ—
`ing fiber optic equipment, that permits the use of a part
`of a speech band, i.e., a voice band, for signaling. See
`also circuit, composite circuit, fiber optic equipment,
`signal, signaling, voice band.
`
`speech plus telegraph: An arrangement of equipment,
`including fiber optic equipment, that pcmiits the use
`of a part of a speech band, i.e., a voice band, for the
`transmission of telegraph signals for data transmission.
`See also data transmission, fiber optic equipment,
`signal, telegraph, transmission, voice band.
`
`speech powered telephone: Synonym sound pow-
`ered telephone.
`
`speech power unit: Synonym volume unit.
`speech scrambler: In communications systems opera~
`tions, a device that converts speech signals into unintel-
`ligible form before transmission in order to obtain some
`measure of privacy in the event of interception, such
`as casual overhearing by unauthorized persons. See also
`intercepting, privacy, signal, speech scrambling,
`transmission.
`
`speech scrambling: In communications systems opera-
`tions,
`(3.) the converting of speech signals, including
`optical signals, into unintelligible form before transmis
`sion and (b) restoring the signals into intelligible form
`at reception, in order to obtain some measure of privacy
`in the event of intcrccption, such as casual overheating,
`by unauthorized persons. See also intercepting, optical
`
`
`
`
`
`
`
`
`
`9
`
`