Fiber U

Outside Plant Fiber Optics

Lesson 8: Fiber Optic Testing

How are fiber optic cables tested?
Objectives: From this lesson you should learn:
What parameters need to be tested

What instruments are used for OSP fiber optic testing
How to perform basic fiber optic testing
Advanced testing for long OSP links
Measurement uncertainty in fiber optic testing
How to troubleshoot problems  

This lesson, another extensive one, is on fiber optic testing, an important subject. After all fiber optic cables are installed, spliced and terminated, they must be tested. For every fiber optic cable plant, you generally need to test for continuity and polarity, end-to-end insertion loss, verify installation with an OTDR and then troubleshoot any problems on every fiber in every cable. If it’s a long outside plant cable with intermediate splices, you will want to verify the individual splices with an OTDR test, since that’s the only way to ensure that each splice is good.

Long distance, high speed links require testing for spectral attenuation, chromatic dispersion and polarization mode dispersion. Links where DWDM or CWDM are used need spectral attenuation testing. These tests, plus insertion loss and OTDR testing are called "Fiber Characterization." Videos and links to fiber characterization are included in this lesson.

If you are the network user, you may also be interested in testing transmitter and receiver power, as power is the measurement that tells you whether the system is operating properly.

Testing involves visual inspection of terminations with a microscope, tracing fibers visually and finding faults, measuring optical power and loss with power meters and light sources, testing with OTDRs and testers for special issues in long distance links. With this lesson, it's important to learn what needs testing and why, what are the potential errors involved in the tests and where certain tests are appropriate.

Student Assignment:
Watch the videos, read the references and take the quizzes (Test Your Comprehension)

FOA YouTube Videos
FOA Lecture 12: Fiber Optic Testing Overview 
FOA Lecture 13: Testing Fiber Visually  
FOA Lecture 14: Testing Optical Power  
FOA Lecture 15: Five Ways To Test Fiber Optic Cable Plants  
FOA Lecture 16: Insertion Loss Testing  
FOA Lecture 17: OTDR Testing  
FOA Lecture 18: OTDR Setup  
FOA Lecture 19: OTDR Measurement Uncertainty  
FOA Lecture 20: Other Fiber Optic Tests  
FOA Lecture 21: Visual Fault Locator Demonstration  
FOA Lecture 28, Fiber Characterization 

Online FOA Reference:
Fiber Optic Testing  
Cleaning and Inspecting Connectors Before Testing 
Fiber Optic Test Instruments 
Visual tracing & fault location
Microscope Inspection of Connectors  
Measuring Optical Power, Units of Measure (dB, dBm) 
Installed Cable Plant Testing (OFSTP-14)  Virtual Hands-On: Insertion loss testing, What Loss Should You Expect?
Patchcord or Single Cable Testing (FOTP-171)

Data Link or Network Testing
OTDR testing  Virtual Hands-On: Using an OTDR
5 different Ways To Test Fiber Optic Cables According To International Standards
Differences in OTDR and insertion loss measurements
Fiber Characterization For Long-haul Networks
YouTube video on testing

Book Chapter:
            FOA Reference Guide to Fiber Optics, Chapter 8

Test Your Knowledge:
Online Quiz
Take the Quiz at the end of Chapter 8 and check your answers  

Extra Credit Reading
Metrology (The Science of Measurements) And Fiber Optics
Reference Cables
Special Applications/Hybrid Cables  
Mismatched Multimode Fiber Losses
Testing cables with different types of connectors.
Loss by Cable Substitution - when other methods will not work
Connector and Splice Loss Testing (FOTP-34)
Testing long haul networks (CD, PMD, Spectral Attenuation)  
FAQs on Fiber Optic Testing
Testing FTTH
Testing PON Splitters and Couplers

Next: Lesson 9: Fiber Optic Network Design  

Return to Lesson Plan


Table of Contents: The FOA Reference Guide To Fiber Optics

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