Fiber Optics Installer (FOI) Certification Exam Guide
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About this ebook
Fiber Optics Installer (FOI) Certification Exam Guide gives you a solid foundation in fiber optics and thorough preparation for the Fiber Optics Installer (FOI) certification. Endorsed by the Electronics Technicians Association, International, this guide serves as both a comprehensive self-study course and a useful desk reference for aspiring fiber optics installers. Coverage includes the basic principles of light, optical fiber construction, safety, fusion, mechanical splicing, connectors, fiber-optic light sources, transmitters, detectors, test equipment, and more. Each chapter meets or exceeds the ETA FOI knowledge competency, with key exam information highlighted for easy reference. Real-world scenarios illustrate how particular solutions are applied in common working environments, giving you a clear understanding of to use the tactics in the field. Chapter exercises and review questions offer plenty of opportunity for practice.
This book helps you prepare for certification, and more importantly, the everyday work the job entails.
- Determine how much you already know with a pre-study assessment
- Find key exam information and terms quickly with chapter-by-chapter objectives
- Study real-world scenarios to understand how concepts are applied
- Pinpoint weak areas with practice and review questions that test your knowledge
If you are seeking a strong knowledge base — and complete exam prep — you will find Fiber Optics Installer (FOI) Certification Exam Guide to be a critically useful reference.
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Fiber Optics Installer (FOI) Certification Exam Guide - Bill Woodward
Table of Contents
Title Page
Copyright
Publisher's Note
Dedication
Acknowledgments
About the Author
Introduction
Assessment Test
Answers to Assessment Test
Chapter 1: History of Fiber Optics and Broadband Access
Evolution of Light in Communication
Evolution of Optical Fiber Manufacturing Technology
Evolution of Optical Fiber Integration and Application
Broadband since the Turn of the Century
Summary
Exam Essentials
Review Questions
Chapter Exercises
Chapter 2: Principles of Fiber-Optic Transmission
The Fiber-Optic Link
Decibels (dB)
Absolute Power
Summary
Exam Essentials
Review Questions
Chapter Exercises
Chapter 3: Basic Principles of Light
Light as Electromagnetic Energy
The Electromagnetic Spectrum
Refraction
Total Internal Reflection
Fresnel Reflections
Summary
Exam Essentials
Review Questions
Chapter Exercises
Chapter 4: Optical Fiber Construction and Theory
Optical Fiber Components
Tensile Strength
Manufacturing Optical Fiber
Mode
Refractive Index Profiles
Summary
Exam Essentials
Review Questions
Chapter Exercises
Chapter 5: Optical Fiber Characteristics
It All Adds Up
Dispersion
Attenuation
Bending Losses
Numerical Aperture
Equilibrium Mode Distribution
Fiber Specifications and Standards
Summary
Exam Essentials
Review Questions
Chapter Exercises
Chapter 6: Safety
Basic Safety
Light Sources
Handling Fiber
Chemicals
Site Safety
Emergencies
Summary
Exam Essentials
Review Questions
Chapter Exercises
Chapter 7: Fiber-Optic Cables
Basic Cable
Cable Components
Cable Types
Cable Duty Specifications
Cable Termination Methods
Blown Fiber
NEC Provisions for Fiber-Optic Cables and Raceways
Cable Markings and Codes
Bend Radius Specifications
Summary
Exam Essentials
Review Questions
Chapter Exercises
Chapter 8: Splicing
Why Splice?
Splicing Safety
Splicing Equipment
Splicing Procedures
Splice Performance Requirements
Summary
Exam Essentials
Review Questions
Chapter Exercises
Chapter 9: Connectors
The Fiber-Optic Connector
Connection Performance
Connector Types
Connector Termination
Cleaning and Inspection
Summary
Exam Essentials
Review Questions
Chapter Exercises
Chapter 10: Fiber-Optic Light Sources and Transmitters
Semiconductor Light Sources
Light Source Performance Characteristics
Transmitter Performance Characteristics
Light Source Safety
Summary
Exam Essentials
Review Questions
Chapter Exercises
Chapter 11: Fiber-Optic Detectors and Receivers
Photodiode Fundamentals
Other Types of Photodiode
Photodiode Responsivity, Efficiency, and Speed
Fiber-Optic Receiver
Receiver Optical Performance Characteristics
Optical Attenuators
Summary
Exam Essentials
Review Questions
Chapter Exercises
Chapter 12: Cable Installation and Hardware
Installation Specifications
Installation Hardware
Installation Methods
Fire Resistance Bonding and Grounding
Hardware Management
Labeling Requirements and Documentation
Polarity
Electrical Codes
Summary
Exam Essentials
Review Questions
Chapter Exercises
Chapter 13: Fiber-Optic System Advantages
The Advantages of Optical Fiber over Copper
Summary
Exam Essentials
Review Questions
Chapter Exercises
Chapter 14: Test Equipment and Link/Cable Testing
Calibration Requirements
Continuity Tester
Visual Fault Locator
Fiber Identifier
Inline Optical Power Monitoring
Optical Return Loss Test Set
Stabilized Light Source and Optical Power Meter
Patch Cord
Test Jumper
Launch Conditions, Mode Filters, and Encircled Flux
ANSI/TIA-526-14 Optical Loss Measurement Methods
Patch Cord Optical Power Loss Measurement
Connector Insertion Loss Measurement
Link Segment and Cabling Subsystem Performance Measurements
Tier 1 Testing
Tier 2 Testing
Optical Time-Domain Reflectometer
Emerging Testing Standards
Summary
Exam Essentials
Review Questions
Chapter Exercises
Appendix: Answers to Review Questions
Chapter 1: History of Fiber Optics and Broadband Access
Chapter 2: Principles of Fiber-Optic Transmission
Chapter 3: Basic Principles of Light
Chapter 4: Optical Fiber Construction and Theory
Chapter 5: Optical Fiber Characteristics
Chapter 6: Safety
Chapter 7: Fiber-Optic Cables
Chapter 8: Splicing
Chapter 9: Connectors
Chapter 10: Fiber-Optic Light Sources and Transmitters
Chapter 11: Fiber-Optic Detectors and Receivers
Chapter 12: Cable Installation and Hardware
Chapter 13: Fiber-Optic System Advantages
Chapter 14: Test Equipment and Link/Cable Testing
Glossary
End User License Agreement
List of Illustrations
Figure 1.1
Figure 2.1
Figure 2.2
Figure 2.3
Figure 2.4
Figure 2.5
Figure 3.1
Figure 3.2
Figure 3.3
Figure 3.4
Figure 3.5
Figure 3.6
Figure 3.7
Figure 3.8
Figure 3.9
Figure 3.10
Figure 3.11
Figure 3.12
Figure 3.13
Figure 4.1
Figure 4.2
Figure 4.3
Figure 4.4
Figure 4.5
Figure 4.6
Figure 4.7
Figure 4.8
Figure 4.9
Figure 4.10
Figure 4.11
Figure 4.12
Figure 5.1
Figure 5.2
Figure 5.3
Figure 5.4
Figure 5.5
Figure 5.6
Figure 5.7
Figure 5.8
Figure 5.9
Figure 5.10
Figure 5.11
Figure 5.12
Figure 5.13
Figure 5.14
Figure 6.1
Figure 6.2
Figure 6.3
Figure 7.1
Figure 7.2
Figure 7.3
Figure 7.4
Figure 7.5
Figure 7.6
Figure 7.7
Figure 7.8
Figure 7.9
Figure 7.10
Figure 7.11
Figure 7.12
Figure 7.13
Figure 7.14
Figure 7.15
Figure 7.16
Figure 7.17
Figure 7.18
Figure 7.19
Figure 7.20
Figure 7.21
Figure 7.22
Figure 7.23
Figure 7.24
Figure 7.25
Figure 7.26
Figure 7.27
Figure 7.28
Figure 7.29
Figure 7.30
Figure 7.31
Figure 7.32
Figure 7.33
Figure 7.34
Figure 8.1
Figure 8.2
Figure 8.3
Figure 8.4
Figure 8.5
Figure 8.6
Figure 8.7
Figure 8.8
Figure 8.9
Figure 8.10
Figure 8.11
Figure 8.12
Figure 8.13
Figure 8.14
Figure 8.15
Figure 8.16
Figure 8.17
Figure 8.18
Figure 8.19
Figure 8.20
Figure 8.21
Figure 8.22
Figure 8.23
Figure 8.24
Figure 8.25
Figure 8.26
Figure 8.27
Figure 8.28
Figure 8.29
Figure 8.30
Figure 8.31
Figure 8.32
Figure 8.33
Figure 8.34
Figure 8.35
Figure 8.36
Figure 8.37
Figure 8.38
Figure 8.39
Figure 8.40
Figure 8.41
Figure 8.42
Figure 8.43
Figure 8.44
Figure 8.45
Figure 8.46
Figure 8.47
Figure 8.48
Figure 9.1
Figure 9.2
Figure 9.3
Figure 9.4
Figure 9.5
Figure 9.6
Figure 9.7
Figure 9.8
Figure 9.9
Figure 9.10
Figure 9.11
Figure 9.12
Figure 9.13
Figure 9.14
Figure 9.15
Figure 9.16
Figure 9.17
Figure 9.18
Figure 9.19
Figure 9.20
Figure 9.21
Figure 9.22
Figure 9.23
Figure 9.24
Figure 9.25
Figure 9.26
Figure 9.27
Figure 9.28
Figure 9.29
Figure 9.30
Figure 9.31
Figure 9.32
Figure 9.33
Figure 9.34
Figure 9.35
Figure 9.36
Figure 9.37
Figure 9.38
Figure 9.39
Figure 9.40
Figure 9.41
Figure 9.42
Figure 9.43
Figure 9.44
Figure 9.45
Figure 9.46
Figure 9.47
Figure 9.48
Figure 9.49
Figure 9.50
Figure 9.51
Figure 9.52
Figure 9.53
Figure 9.54
Figure 9.55
Figure 9.56
Figure 9.57
Figure 9.58
Figure 9.59
Figure 9.60
Figure 9.61
Figure 9.62
Figure 9.63
Figure 9.64
Figure 9.65
Figure 9.66
Figure 9.67
Figure 9.68
Figure 9.69
Figure 9.70
Figure 9.71
Figure 9.72
Figure 9.73
Figure 9.74
Figure 9.75
Figure 9.76
Figure 9.77
Figure 9.78
Figure 9.79
Figure 9.80
Figure 9.81
Figure 9.82
Figure 9.83
Figure 9.84
Figure 9.85
Figure 9.86
Figure 9.87
Figure 9.88
Figure 9.89
Figure 9.90
Figure 9.91
Figure 9.92
Figure 9.93
Figure 9.94
Figure 9.95
Figure 9.96
Figure 9.97
Figure 9.98
Figure 9.99
Figure 9.100
Figure 9.101
Figure 9.102
Figure 9.103
Figure 9.104
Figure 9.105
Figure 9.106
Figure 9.107
Figure 9.108
Figure 9.109
Figure 9.110
Figure 9.111
Figure 9.112
Figure 9.113
Figure 10.1
Figure 10.2
Figure 10.3
Figure 10.4
Figure 10.5
Figure 10.6
Figure 10.7
Figure 10.8
Figure 10.9
Figure 10.10
Figure 10.11
Figure 10.12
Figure 10.13
Figure 10.14
Figure 10.15
Figure 10.16
Figure 10.17
Figure 10.18
Figure 10.19
Figure 10.20
Figure 10.21
Figure 10.22
Figure 11.1
Figure 11.2
Figure 11.3
Figure 11.4
Figure 11.5
Figure 11.6
Figure 11.7
Figure 11.8
Figure 11.9
Figure 12.1
Figure 12.2
Figure 12.3
Figure 12.4
Figure 12.5
Figure 12.6
Figure 12.7
Figure 12.8
Figure 12.9
Figure 12.10
Figure 12.11
Figure 12.12
Figure 12.13
Figure 12.14
Figure 12.15
Figure 12.16
Figure 12.17
Figure 12.18
Figure 12.19
Figure 12.20
Figure 12.21
Figure 12.22
Figure 12.23
Figure 12.24
Figure 12.25
Figure 12.26
Figure 12.27
Figure 12.28
Figure 12.29
Figure 14.1
Figure 14.2
Figure 14.3
Figure 14.4
Figure 14.5
Figure 14.6
Figure 14.7
Figure 14.8
Figure 14.9
Figure 14.10
Figure 14.11
Figure 14.12
Figure 14.13
Figure 14.14
Figure 14.15
Figure 14.16
Figure 14.17
Figure 14.18
Figure 14.19
Figure 14.20
Figure 14.21
Figure 14.22
Figure 14.23
Figure 14.24
Figure 14.25
Figure 14.26
Figure 14.27
Figure 14.28
Figure 14.29
Figure 14.30
Figure 14.31
Figure 14.32
Figure 14.33
Figure 14.34
Figure 14.35
Figure 14.36
Figure 14.37
Figure 14.38
Figure 14.39
Figure 14.40
Figure 14.41
Figure 14.42
Figure 14.43
Figure 14.44
Figure 14.45
Figure 14.46
Figure 14.47
Figure 14.48
Figure 14.49
Figure 14.50
Figure 14.51
Figure 14.52
Figure 14.53
Figure 14.54
Figure 14.55
Figure 14.56
Figure 14.57
Figure 14.58
Figure 14.59
Figure 14.60
Figure 14.61
Figure 14.62
List of Tables
Table 2.1
Table 2.2
Table 2.3
Table 2.4
Table 3.1
Table 5.7
Table 5.10
Table 5.8
Table 5.1
Table 5.2
Table 5.3
Table 5.4
Table 5.5
Table 5.6
Table 5.11
Table 5.12
Table 5.13
Table 7.1
Table 7.2
Table 7.3
Table 8.1
Table 8.2
Table 8.3
Table 8.4
Table 9.1
Table 9.2
Table 9.3
Table 9.4
Table 10.1
Table 10.2
Table 10.3
Table 10.4
Table 10.5
Table 10.6
Table 10.7
Table 10.8
Table 10.9
Table 10.10
Table 10.11
Table 10.12
Table 10.13
Table 12.1
Table 12.2
Table 12.3
Table 12.4
Table 13.1
Table 13.2
Table 13.3
Table 13.4
Table 14.1
Table 14.2
Table 14.3
Table 14.4
Fiber Optics Installer (FOI)
Certification Exam Guide
Bill Woodward
Wiley LogoAcquisitions Editor: Mariann Barsolo
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Copyright © 2015 by John Wiley & Sons, Inc., Indianapolis, Indiana
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Dear Reader,
Thank you for choosing Fiber Optics Installer (FOI) Certification Exam Guide. This book is part of a family of premium-quality Sybex books, all of which are written by outstanding authors who combine practical experience with a gift for teaching.
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Acknowledgments
Writing a book is a team effort that takes a dedicated group of professionals. I am very fortunate to have been able to work with this team of talented and dedicated individuals.
First, I would like to thank Sybex for giving me the opportunity to write this book. Special thanks to Acquisitions Editor Mariann Barsolo, Production Editor Dassi Zeidel, Developmental Editor Kelly Talbot, Editorial Manager Pete Gaughan, and editorial staff Connor O'Brien, Rebekah Worthman, Rayna Erlick, and Jenni Housh for the outstanding job you did guiding me through this project from start to finish.
Thanks to Chuck Schue and Randy Hall at UrsaNav, Inc., for all your support with this project.
Thanks, Charlie Husson, for the outstanding job with the technical edits. You are an exceptional engineer, great mentor, and friend. I have learned so much from you over the years and look forward to working with you on future projects.
Many companies also provided technical information, equipment, and photographs. Special thanks to Donald Stone from KITCO Fiber Optics, Jay S. Tourigny from MicroCare, Mark Messer from Carlisle Interconnect Technologies, Dede Starnes and Ryan Spillane from Corning Cable Systems, Bob Scharf from Moog Protokraft, Bill Reid from Amphenol Fiber Systems International, Earle Olson from TE Connectivity, Peter Koudelka from PROMET International Inc., Chuck Casbeer from Infotec IT and Leadership Training, Bruno Huttner from Luciol Instruments, Laurence N. Wesson from Aurora Optics Inc., Art Schweiss from Electronic Manufacturers' Agents Inc., Kevin Lefebvre from EigenLight Corporation, Matt Krutsch from COTSWORKS, Ed Forrest from ITW Chemtronics, Mike Gleason from Panduit, Scott Kale from Norfolk Wire, Christine Pons from OptiConcepts, and Dave Edwards from W.R. Systems.
Dick Glass has been a friend, mentor, and co-worker for many years; he has spent many hours guiding me through various writing projects. I feel very blessed to have met Dick and greatly appreciate his guidance over the years and his assistance with this project.
Thanks to the host of people behind the scenes who I did not mention for all your efforts to make this book the best that it can be.
Last but not least, thank you to my family—to the love of my life, my beautiful wife Susan, for making this possible; to my children, Mike, Brandon, Eric, Nathan, and Kathryn; and to my grandchildren for your patience, inspiration, encouragement, and prayers. I am the luckiest man alive to have all of you in my life.
About the Author
Bill Woodward is the director of C5ISR Engineering Products with UrsaNav, Inc., an engineering services company. Bill has been teaching fiber optics and other technical courses since 1992. He has more than 25 years of experience in the design, operation, maintenance, troubleshooting, and repair of electronic and electrical systems.
Bill is licensed in the Commonwealth of Virginia as a professional electrical engineer. He is chairman of SAE International's Aerospace Fiber Optics and Applied Photonics Committee, AS-3, as well as chairman of the AS-3B2 Education and Design Working Group. He is also a member of the Electronics Technicians Association (ETA) International; he has served four terms as chairman of the ETA and has been chair of the Fiber Optic Committee for over a decade.
Introduction
The term broadband
commonly refers to high-speed Internet access that is always on and faster than the traditional dial-up access. Without fiber optics, broadband as we know it today would not exist. Fiber optics is the backbone of the global telecommunications system. No other transmission medium can move the high rates of data over the long distances required to support the global telecommunications system. This technology works so well that the typical user may not be aware that it even exists.
This book focuses on building a solid foundation in fiber-optic theory and application. It describes in great detail fiber-optic cable technology, connectorization, and splicing. It examines the electronic technology built into fiber-optic receivers, transmitters, and test equipment that makes incredible broadband download and upload speeds possible. In addition, many current industry standards pertaining to optical fiber, connector, splice, and network performance are discussed in detail.
Who This Book Is For
If you are standing in your neighborhood bookstore browsing through this book, you may be asking yourself whether you should buy it. The procedures in this book are illustrated and written in English rather than technospeak.
That's because this book was designed specifically to help unlock the mysteries of fiber optics. Fiber optics can be a confusing topic; it has its own language, acronyms, and standards. This book was developed with the following types of people in mind:
Information technology (IT) professionals who can use this book to gain a better understanding and appreciation of a structured fiber-optic cabling system
IT managers who are preparing to install a new computer system
Do-it-yourselfers who need to install a few new cabling runs in their facility and want to get it right the first time
New cable installers who want to learn more than just what it takes to pull a cable through the ceiling and terminate it to the patch panel
Students taking introductory courses in LANs and cabling
Students preparing for the ETA fiber-optics installer (FOI) certification
This book is an excellent reference for anyone currently working in fiber optics as well as those who are just starting to learn about fiber optics. The book covers in detail all of the competencies of the Electronics Technicians Association International (ETA) (FOI) certification.
ETA's FOI Certification Program
The ETA's FOI certification program is the most comprehensive in the industry. It requires students to attend an ETA-approved training school. Each student must achieve a score of 75 percent or greater on the written exam and satisfactorily complete all the hands-on requirements. Those who are interested in obtaining ETA FOI certification can visit the ETA's website at www.eta-i.org and get the most up-to-date information on the program and a list of approved training schools.
The ETA FOI certification requires no prerequisite and is designed for anyone who is interested in learning how to become a fiber-optic installer. The FOI certification is recommended as a prerequisite for the FOT certification, for those who want to learn how to test a fiber-optic link to the current industry standards and how to troubleshoot. Fiber-optic certification demonstrates to your employer that you have the knowledge and hands-on skills required to install, test, and troubleshoot fiber-optic links and systems. With the push to bring fiber optics to every home, these skills are highly sought after.
What This Book Covers
This book's topics run the gamut of fiber-optics technology and application; they include the following:
The history of fiber optics and broadband access
The principles of fiber-optic transmission
The basic principles of light
Optical fiber construction and theory
Optical fiber characteristics
Safety
Fiber-optic cables
Fusion and mechanical splicing
Connectors
Fiber-optic light sources and transmitters
Fiber-optic detectors and receivers
Cable installation and hardware
Fiber-optic system advantages
Test equipment and link/cable testing
This book provides you with a solid foundation in fiber-optic technologies and practices. The book is loaded with valuable information, including the following elements:
Assessment test Directly following this introduction is an assessment test that you should take. It is designed to help you determine how much you already know. Each question is tied to a topic discussed in the book. Using the results of the assessment test, you can figure out the areas where you need to focus your study. Of course, we do recommend that you read the entire book.
Competency-by-competency coverage of the topics you need to know Each chapter lists the ETA FOI exam knowledge competencies covered in that chapter, followed by a detailed discussion of each competency.
Chapter exercises You'll find exercises designed to give you the important hands-on experience that is critical for your exam preparation. The exercises support the topics of the chapter, and they walk you through the steps necessary to perform a particular function.
Real World Scenarios Because reading a book isn't enough for you to learn how to apply these topics in your everyday duties, we have provided Real World Scenarios in special sidebars. These explain when and why a particular solution would make sense in a working environment that you'd actually encounter.
Exam Essentials To highlight what you learn, you'll find a list of Exam Essentials at the end of each chapter. The Exam Essentials section briefly highlights the topics that need your particular attention as you prepare for the FOI exam.
Review questions, complete with detailed explanations Each chapter is followed by a set of review questions that test what you learned in the chapter. The questions are written with the exam in mind, meaning that they are designed to have the same look and feel as what you'll see on the exam. Answers to the review questions with detailed explanations can be found in the appendix.
Glossary Throughout each chapter, you will be introduced to important terms and concepts that you will need to know for the FOI exam. These terms appear in italics within the chapters. At the end of the book, a detailed glossary gives definitions for these terms, as well as other general terms you should know.
How to Use This Book
To understand the way this book is put together, you must learn about a few of the special conventions that were used. Here are some of the items you will commonly see.
Italicized words indicate new terms. After each italicized term, you will find a definition.
Tips will be formatted like this. A tip is a special bit of information that can make your work easier or make an installation go more smoothly.
Notes are formatted like this. When you see a note, it usually indicates some special circumstance to make note of. Notes often include out-of-the-ordinary information about working with a telecommunications infrastructure.
Warnings are found within the text whenever a technical situation arises that may cause damage to a component or cause a system failure of some kind. Additionally, warnings are placed in the text to call particular attention to a potentially dangerous situation.
Key terms are used to introduce a new word or term that you should be aware of. Just as in the worlds of networking, software, and programming, the world of cabling and telecommunications has its own language.
Sidebars
This special formatting indicates a sidebar. Sidebars are entire paragraphs of information that, although related to the topic being discussed, fit better into a standalone discussion. They are just what their name suggests: a sidebar discussion.
This book provides a solid foundation for the serious effort of preparing for the ETA FOI certification exam. To best benefit from this book, you might want to use the following study method:
Take the assessment test to identify your weak areas.
Study each chapter carefully. Do your best to fully understand the information.
Read over the Real World Scenarios to improve your understanding of how to use what you learn in the book.
Study the Exam Essentials to make sure that you are familiar with the areas you need to focus on.
Answer the review questions at the end of each chapter.
Work through the Chapter Exercises at the end of the chapter.
Take note of the questions you did not understand, and study the corresponding sections of the book again.
Go back over the Exam Essentials.
To learn all the material required to pass the exam, you will need to study regularly and with discipline before and while attending an ETA-approved training course. Try to set aside the same time every day to study, and select a comfortable and quiet place in which to do it. Do not wait until the break before the exam to start studying. Remember: if you have any questions about the material you are learning, ask your instructor.
Enjoy!
Have fun reading this book—it has been fun writing it. I hope that it will be a valuable resource to you and will answer at least some of your questions on fiber optics. As always, I love to hear from readers, you can reach me at wrwoodward2013@gmail.com.
Assessment Test
The decade that saw the first full-scale commercial application of fiber-optic communication systems was
A. The 1880s
B. The 1920s
C. The 1960s
D. The 1970s
Which of the following groups describes the components in a fiber-optic link?
A. Transmitter, receiver, optical fiber, decoder
B. Transmitter, receiver, optical fiber, connectors
C. Transmitter, receiver, optical fiber
D. Transmitter, receiver, optical fiber, cabling
In a fiber-optic link, which component has an input of electrical energy and an output of light energy?
A. Connector
B. Optical fiber
C. Receiver
D. Transmitte
A 50 percent reduction in signal strength is a loss of ____________________________.
A. 3dB
B. 3dBm
C. 7dB
D. 7dBm
Refraction is caused by ____________________________.
A. Light changing color as it passes from one medium into another
B. Light changing speed as it passes from one medium into another
C. Light changing frequency as it passes from one medium into another
D. Light changing direction within a single medium
A Fresnel reflection will occur because light changes ____________________________ as it moves from a material with a given n into a material with a different n.
A. Direction
B. Speed
C. The critical angle
D. The index of refraction
Listed from innermost to outermost, the components of an optical fiber are
A. Cladding, core, coating
B. Core, cladding, coating
C. Cladding, coating, core
D. Core, coating, cladding
Modal dispersion is caused when
A. Light escapes into the cladding from the core.
B. Light rays follow different paths along the fiber core.
C. A fiber is split into several parts.
D. Light encounters a break in the fiber.
For a fiber of a given bandwidth, as the length of the fiber increases, the bandwidth
A. Increases
B. Decreases
C. Does not change
D. Is independent of the length
Because infrared lasers cannot be seen, they ____________________________.
A. Cannot hurt your eyes
B. Are not useful in fiber optics
C. Are especially dangerous to your eyes
D. Require special instruments
Which of the following describes the four components of a fiber optic cable?
A. Core, cladding, coating, buffer
B. Fiber, buffer, strength member, jacket
C. Core, buffer, jacket, coating
D. Fiber, buffer, strength member, coating
Article ____________________________ of the National Electric Code covers optical fiber cables and raceways.
A. 250
B. 660
C. 770
D. 810
Which part of the connector holds the fiber in place?
A. The ferrule
B. The cap
C. The boot
D. The body
Which geometry of the connector endface ensures a physical contact (PC) finish?
A. Flat
B. Rough
C. Curved
D. Lensed
The puck is used to
A. Keep a firm grip on the connector for polishing.
B. Hold down the abrasive material during polishing.
C. Keep the abrasive surface clean.
D. Keep the ferrule perpendicular to the polishing surface.
Per ANSI/TIA-568-C.3 the strain relief for a single-mode connector should be which color?
A. Aqua
B. Black
C. Blue
D. Beige
Lasers emit photons that are in phase through a process called ____________________________ emission.
A. Coherent
B. Incoherent
C. Stimulated
D. Spontaneous
Fiber-optic receivers use a(n) ____________________________ to convert the light energy from the optical fiber into electrical energy.
A. Photoresistor
B. Photodiode
C. Phototransistor
D. LED
A cable's minimum bend radius specification is greater
A. During installation
B. After installation
C. When the temperature is higher
D. When it is in a cable tray
A pulling eye is attached to
A. The cable's outer jacket
B. The cable's strength member
C. The fiber
D. The armor
What is the jacket color of laser-optimized simplex cordage?
A. Orange
B. Slate
C. Blue
D. Aqua
Hybrid cable as applied to fiber optics combines
A. Loose and tight buffers
B. Single-mode and multimode optical fibers
C. Optical fibers and current-carrying electrical conductors
D. Plastic and glass optical fibers
A mechanical splice typically ____________________________ uses to reduce or eliminate Fresnel reflections.
A. Epoxy
B. A high-voltage electric arc
C. Index matching gel
D. Isopropyl alcohol
Only a ____________________________ laser is considered eye safe.
A. Class I
B. Class II
C. Class III
D. Class IV
The ____________________________ is the laser primarily used in multimode transmitters.
A. DFB
B. VCSEL
C. Fabry-Pérot
D. LED
Which types of optical fibers should be used for the physical layer when multiple transmitters are operating in parallel?
A. OS1, OS2
B. OS3, OS4
C. OM1, OM2
D. OM3, OM4
____________________________ is required to ensure the proper operation of bidirectional fiber-optic communication systems that use separate transmit and receive optical fibers.
A. Common equipment
B. A demarcation point
C. Polarity
D. A first-level backbone
When is a splice enclosure used?
A. Whenever a fiber has been spliced
B. When a splice must be placed underground
C. When a splice must be placed underwater
D. Splice enclosures are optional.
What is the purpose of a patch panel?
A. It takes the place of a splice enclosure.
B. It fills a hole where fiber has been installed.
C. It is used to route signals between cables.
D. It provides a permanent link between two pieces of hardware.
____________________________ is the administration standard for telecommunications infrastructures.
A. ANSI/TIA-568-C.3
B. ANSI/TIA-606-B
C. ANSI/TIA-568-C.0
D. Article 770
Optical fiber offers ____________________________ bandwidth and ____________________________ attenuation than twisted-pair or coaxial cable.
A. Less, more
B. Equal, more
C. Greater, more
D. Greater, less
Encircled flux launch conditions were developed to improve the accuracy of ____________________________ insertion loss measurements.
A. Multimode
B. Single-mode
C. Multimode and single-mode
D. Multifiber
The ____________________________ is a device that launches a pulse or pulses of light into one end of an optical fiber and records the amount of light energy that is reflected back.
A. Continuity tester
B. OLTS
C. VFL
D. OTDR
Which broadband technology moves the highest rates of data over the greatest distances?
A. Fiber optics
B. Digital Subscriber Line (DSL)
C. Broadband over Power Lines (BPL)
D. Wi-Fi
In fiber optics, ____________________________ is typically used to describe the output of a light source.
A. Frequency
B. Wavelength
C. Hertz
D. Kilometers
Light traveling across a small air gap between two optical fibers will produce ____________________________.
A. Total internal reflection
B. Electromagnetic radiation
C. A Fresnel reflection
D. The Index of Refraction
The optical trench surrounds the ____________________________ of multimode or single-mode bend-insensitive optical fibers.
A. Core
B. Cladding
C. Coating
D. Buffer
Which optical fiber designation offers a minimum effective modal bandwidth-length product of 4700 MHz · km?
A. OM1
B. OM2
C. OM3
D. OM4
What type of bending loss may not be visible when looking at the fiber-optic cable?
A. Macrobend
B. Microbend
C. Intrinsic
D. Attenuation
The maximum attenuation allowable for OM1 fiber at 850nm is ____________________________.
A. 0.5 dB/km
B. 1.0 dB/km
C. 1.5 dB/km
D. 3.5 dB/km
Answers to Assessment Test
D. The first full-scale commercial application of fiber-optic communication systems occurred in 1977, when both AT&T and GTE began using fiber-optic telephone systems for commercial customers.
B. The fiber-optic link requires a transmitter to send the signal, a receiver to capture the signal, optical fiber to carry the signal, and connectors to provide an interface for the optical fiber and the equipment.
D. In order for a signal to be sent through optical fiber, the transmitter must first convert it from electrical energy into light.
A. Reducing signal strength by one-half is a 3dB loss.
B. Refraction, or the change in the direction of light as it changes speed passing from one material into another, is a key component in fiber-optic transmissions.
B. When light changes speed as it moves from a material with a given index of refraction into a material with a different index of refraction, a Fresnel reflection occurs.
B. The core is at the center of the optical fiber; the cladding surrounds the core, and the coating surrounds the cladding.
B. Modal dispersion is caused when light rays follow different paths in the fiber.
B. Because dispersion increases with the length of the fiber, the usable bandwidth of the fiber decreases as the signal pulses must be kept farther apart to avoid overlapping.
C. Because infrared lasers are invisible, you cannot know when they are on, even if you are looking directly into a fiber. You should always make sure the fiber is disconnected from the light source before looking into it with your bare eyes or optical instruments.
B. The core, cladding, and coating of the fiber itself are considered one component of the cable, with the rest being the buffer, strength member, and jacket.
C. Article 770 of the National Electrical Code defines requirements for optical fiber cables and raceways.
A. Beginning at the working end of the connector, the ferrule holds the fiber in place. The ferrule must hold the fiber exactly centered in its endface for the best possible connection, so its construction is critical.
C. To ensure physical contact (PC) between optical fiber ends, the best endface geometry is a convex curve. This curved, or PC finish, ensures that the highest feature or apex on the endface is the center of the optical fiber end.
D. The polishing fixture, or puck as it is typically referred to, is used to ensure that the ferrule stays perpendicular to the polishing film during the polishing process.
C. Per ANSI/TIA-568-C.3 the strain relief for a single-mode connector should be blue in color.
C. Every photon that escapes the optical cavity is a duplicate of the first photon to escape. These photons have the same wavelength, phase relationship, and direction as the first photon. This process of generating light energy is called stimulated emission.
B. In a fiber-optic receiver, it's the job of the photodiode to convert the light energy received from the optical fiber into electrical energy.
A. The minimum installation bend radius is the short-term bend radius, and the minimum operational bend radius is the long-term bend radius. The minimum short-term bend radius is actually the larger of the two because of the tensile stresses that may be placed on the cable during installation.
B. The pulling eye is specially designed to attach to the cable's strength member at one end and a pulling line at the other.
D. TIA-598-C defines premises cable jacket colors; aqua is the jacket color for laser-optimized multimode optical fiber used for non-military applications.
B. Hybrid cable, as applied to fiber optics, combines multimode and single-mode optical fibers in one cable. Hybrid cable should not be confused with composite cable, although the terms have been used interchangeably in the past.
C. A mechanical splice aligns the cleaved optical fibers and holds them in place. Index matching gel inside the mechanical splice reduces or eliminates Fresnel reflections.
A. Under normal operating conditions, Class I lasers do not producing damaging radiation levels.
B. Currently, VCSEL multimode transmitters support only 850nm operation with 50/125μm or 62.5/125μm optical fiber. The VCSEL can support data rates as high as 10Gbps.
D. As defined in IEEE Standard 802.3-2012, Section 6, when multiple transmitters are operating in parallel, multimode OM3 or OM4 optical fiber should be used for the physical layer.
C. Polarity is required to ensure the proper operation of bidirectional fiber-optic communication systems that use separate transmit and receive optical fibers. It ensures that there is an end-to-end transmission path between the transmitter and the receiver of a channel.
A. A splice enclosure is used whenever two fibers have been spliced to protect the splice from exposure and strain.
C. A patch panel is an interconnection point for fiber-optic cables. They allow signals to be routed from one cable to another with a patch cord or jumper.
B. ANSI/TIA-606-B is the administration standard for telecommunications infrastructures. This document contains detailed information on conventions for labeling optical fiber connections within buildings, datacenters, and between buildings that share a telecommunication network.
D. Optical fiber offers the highest bandwidth and the least attenuation of any medium currently available.
A. Encircled flux launch conditions for all multimode insertion loss measurements has been added to IEC 61280-4-1 Edition 2, ANSI/TIA-568-C.0, and ANSI/TIA-526-14-B. The addition of this requirement arose from the need to improve the accuracy of multimode insertion loss measurements.
D. The OTDR is nothing more than a device that launches a pulse or pulses of light into one end of an optical fiber and records the amount of light energy that is reflected back. It provides a graphical representation of what is happening in the fiber-optic link or cable under test.
A. Without fiber optics, broadband as we know it today would not exist. No other transmission medium can move the high rates of data over the long distances required to support the global telecommunications system.
B. Wavelength or frequency can be used to describe electromagnetic energy; however, wavelength is typically used to describe the output of a fiber-optic light source.
C. A Fresnel reflection occurs when light changes speed as it moves from the optical fiber to the air and from the air to the optical fiber.
A. The optical trench surrounds the core of the optical fiber. It has a lower refractive index than the core or the cladding.
D. The minimum effective bandwidth-length product for a 50/125μm laser optimized OM4 multimode optical fiber is 4700MHz · km.
B. Microbends are small distortions of the boundary layer between the core and cladding caused by crushing or pressure. Microbends are very small and may not be visible when looking at the fiber-optic cable.
D. ISO/IEC 11801 defines the performance of OM1; the maximum attenuation at 850nm is 3.5dB for a length of one kilometer.
Chapter 1
History of Fiber Optics and Broadband Access
The following ETA Fiber-Optics Installer competencies are covered in this chapter:
correct Trace the evolution of light in communication.
correct Summarize the evolution of optical fiber manufacturing technology.
correct Track the evolution of optical fiber integration and application.
correct Describe the role of fiber optics in high-speed Internet access.
Like many technological achievements, fiber-optic communications grew out of a succession of quests, some of them apparently unrelated. It is important to study the history of fiber optics to understand that the technology as it exists today is relatively new and still evolving.
This chapter discusses the major accomplishments that led to the creation of high-quality optical fibers and their use in high-speed communications and data transfer, as well as their integration into existing communications networks.
In this chapter, you will learn to
Recognize the refraction of light
Identify total internal reflection
Detect crosstalk between multiple optical fibers
Recognize attenuation in an optical fiber
Evolution of Light in Communication
Hundreds of millions of years ago, the first bioluminescent creatures began attracting mates and luring food by starting and stopping chemical reactions in specialized cells. Over time, these animals began to develop distinctive binary, or on-off, patterns to distinguish one another and communicate intentions quickly and accurately. Some of them have evolved complex systems of flashing lights and colors to carry as much information as possible in a single glance. These creatures were the first to communicate with light, a feat instinctive to them but tantalizing and elusive to modern civilization until recently.
Early Forms of Light Communication
Some of the first human efforts to communicate with light consisted of signal fires lit on hilltops or towers to warn of advancing armies, and lighthouses that marked dangerous coasts for ancient ships and gave them reference points in their journeys. To the creators of these signals, light's tremendous speed (approximately 300,000 kilometers per second) made its travel over great distances seem instantaneous.
An early advance in these primitive signals was the introduction of relay systems to extend their range. In some cases, towers were spread out over hundreds of kilometers, each one in the line of sight of the next. With this system, a beacon could be relayed in the time it took each tower guard to light a fire—a matter of minutes—while the fastest transportation might have taken days. Because each tower only needed in its line of sight the sending and receiving towers, the light, which normally travels in a straight line, could be guided around obstacles such as mountains as well as over the horizon. As early as the fourth century A.D., Empress Helena, the mother of Constantine, was believed to have sent a signal from Jerusalem to Constantinople in a single day using a relay system.
The principle behind signal relay towers is still used today in the form of repeaters, which amplify signals attenuated by travel over long distances through optical fibers.
Early signal towers and lighthouses, for all their usefulness, were still able to convey only very simple messages. Generally, no light meant one state, whereas a light signaled a change in that state. The next advance needed was the ability to send more detailed information with the light. A simple but notable example is the signal that prompted Paul Revere's ride at the start of the American Revolution. By prearranged code, one light hung in the tower of Boston's Old North Church signaled a British attack by land; two lights meant an invasion by sea. The two lamps that shone in the tower not only conveyed a change in state, but also provided a critical detail about that change.
The Quest for Data Transmission
Until the 1800s, light had proven to be a speedy way to transmit simple information across great distances, but until new technologies were available, its uses were limited. It took a series of seemingly unrelated discoveries and inventions to harness the properties of light through optical fibers.
The first of these discoveries was made by Willebrord van Roijen Snell, a Dutch mathematician who in 1621 wrote the formula for the principle of refraction, or the bending of light as it passes from one material into another. The phenomenon is easily observed by placing a stick into a glass of water. When viewed from above, the stick appears to bend because light travels more slowly through the water than through the air. Snell's formula, which was published 70 years after his death, stated that every transparent substance had a particular index of refraction, and that the amount that the light would bend was based on the relative refractive indices of the two materials through which the light was passing. Air has an approximate refractive index of 1 and water has a refractive index of 1.33.
The next breakthrough came from Jean-Daniel Colladon, a Swiss physicist, and Jacques Babinet, a French physicist. In 1840, Colladon and Babinet demonstrated that bright light could be guided through jets of water through the principle of total internal reflection. In their demonstration, light from an arc lamp was used to illuminate a container of water. Near the bottom of the container was a hole through which the water could escape. As the water poured out of the hole, the light shining into the container followed the stream of water. Their use of this discovery, however, was limited to illuminating decorative fountains and special effects in operas. It took John Tyndall, a natural philosopher and physicist from Ireland, to bring the phenomenon to greater attention. In 1854, Tyndall performed the demonstration before the British Royal Society and made it part of his published works in 1871, casting a shadow over the contribution of Colladon and Babinet. Tyndall is now widely credited with discovering total internal reflection, although Colladon and Babinet had demonstrated it 14 years previously.
Total internal reflection takes place when light passing through a material with a higher index of refraction (the water in the experiment) hits a boundary layer with a material that has a lower index of refraction (the air). When this takes place, the boundary layer becomes reflective, and the light bounces off the boundary layer, remaining contained within the material with the higher index of refraction.
Shortly after Tyndall, Colladon, and Babinet laid the groundwork for routing light through a curved material, another experiment took place that showed how light could be used to carry higher volumes of data.
In 1880, Alexander Graham Bell demonstrated his photophone, one of the first true attempts to carry complex signals with light. It was also the first device to transmit signals wirelessly. The photophone gathered sunlight onto a mirror attached to a mouthpiece that vibrated when a user spoke into it. The vibrating mirror reflected the light onto a receiver coated with selenium, which produced a modulated electrical signal that varied with the light coming from the sending device. The electrical signal went to headphones where the original voice input was reproduced.
Bell's invention suffered from the fact that outside influences such as dust or stray light confused the signals, and clouds or other obstructions to light rendered the device inoperable. Although Bell had succeeded in transmitting a modulated light signal nearly 200 meters, the photophone's limitations had already fated it to be eclipsed by Bell's earlier invention, the telephone. Until the light could be modulated and guided as well as electricity could, inventions such as the photophone would continue to enjoy only novelty status.
Evolution of Optical Fiber Manufacturing Technology
John Tyndall's experiment in total internal reflection had led to attempts to guide light with more control than could be achieved in a stream of water. One such effort by William Wheeler in 1880, the same year that Bell's photophone made its debut, used pipes with a reflective coating inside that guided light from a central arc lamp throughout a house. As with other efforts of the time, there was no attempt to send meaningful information through these conduits—merely to guide light for novelty or decorative purposes. The first determined efforts to use guided light to carry information came out of the medical industry.
Controlling the Course of Light
Doctors and researchers had long tried to create a device that would allow them to see inside the body with minimal intrusion. They had begun experimenting with bent glass and quartz rods, bringing them tantalizingly close to their goal. These tools could transmit light into the body, but they were extremely uncomfortable and sometimes dangerous for the patient, and there was no way yet to carry an image from the inside of the body out to doctors. What they needed