What is Optical Fiber? - Definition & Concept

An error occurred trying to load this video.

Try refreshing the page, or contact customer support.

Coming up next: NTSC vs. PAL: Difference & Explanation

You're on a roll. Keep up the good work!

Take Quiz Watch Next Lesson
Your next lesson will play in 10 seconds
  • 0:00 Optical Fiber Defined
  • 2:00 Types of Optical Fiber
  • 2:33 Advantages & Limitations
  • 3:05 Lesson Summary
Save Save Save

Want to watch this again later?

Log in or sign up to add this lesson to a Custom Course.

Log in or Sign up

Speed Speed

Recommended Lessons and Courses for You

Lesson Transcript
Instructor: David Whitsett

David has taught computer applications, computer fundamentals, computer networking, and marketing at the college level. He has a MBA in marketing.

Optical fiber is a type of cabling technology that uses light to carry voice and data communications (telecommunications) over distances both great and small. This lesson will provide a definition of optical fiber, explore the different types and explain how the different types are used. We'll also look at the advantages of optical fiber over traditional copper wiring and examine the limitations.

Optical Fiber Defined

An optical fiber is a very thin strand of plastic or glass that is used to transmit messages via light. These strands are bundled together in a protective sheath or cover and the whole assembly (the optical fibers and other parts inside the sheath) is often referred to as fiber optic cable or just fiber.

Think of two people standing at opposite ends of a long dark hallway and signaling each other with flashlights. In the case of optical fiber, the strand (the hallway in the example) can be about as thin as a human hair, and the material it is made of (glass or plastic) is very pure. So the messages transmitted via light can travel a very long way, across oceans.

But, you ask, don't fiber optic cables bend? How does a signal of light, which travels in a straight line (remember the flashlight beam), go around a curve? The answer is in the way a fiber optic cable is built. Wrapped around each strand of optical fiber is cladding, an outer optical material that reflects the light back into the core strand. Think of using a mirror to reflect a beam of light around a corner. Cladding acts as a mirror all along the cable, continuously reflecting light along the cable down the intended path.

The transmitters at either end of an optical fiber cable typically use light-emitting diodes (LEDs) or laser diodes to generate the light. Think of our flashlight example, where the flashlight is the light source. Optical receivers take the light signal from the cable and convert it into an electrical signal. The data moves at a very high rate of speed; think of milliseconds for a message to go across the Atlantic! Why? Light travels faster than an electrical signal through a copper cable.

Fiber attenuation (signal loss) and distortion are dealt with over long runs with the use of fiber optic amplifiers or repeaters. These devices boost the signal at a midpoint and send it back along its way.

To unlock this lesson you must be a Member.
Create your account

Register to view this lesson

Are you a student or a teacher?

Unlock Your Education

See for yourself why 30 million people use

Become a member and start learning now.
Become a Member  Back
What teachers are saying about
Try it risk-free for 30 days

Earning College Credit

Did you know… We have over 200 college courses that prepare you to earn credit by exam that is accepted by over 1,500 colleges and universities. You can test out of the first two years of college and save thousands off your degree. Anyone can earn credit-by-exam regardless of age or education level.

To learn more, visit our Earning Credit Page

Transferring credit to the school of your choice

Not sure what college you want to attend yet? has thousands of articles about every imaginable degree, area of study and career path that can help you find the school that's right for you.

Create an account to start this course today
Try it risk-free for 30 days!
Create an account