What are Fiber-Optics?

Shannon Kietzman

Fiber-optics consist of a bundle of thin glass or plastic strands. This is coated or surrounded in material that allows light to pass through the fibers without escaping out the sides. Signals can pass through them at very high speeds from the point of origin to the destination, with minimal loss in quality or data. Companies use fiber-optics to transmit Internet data, audio information for telephones, and images for television or medical cameras.

Fiber optic cables are strands of glass or plastic that transmit light.
Fiber optic cables are strands of glass or plastic that transmit light.

Basic Function

The concept behind fiber-optics is fairly simple. A user transmits a signal as light, often in the form of a laser beam, through a length of thin strands of glass or plastic. The optical fiber acts as the medium through which the light passes, while a coating on the outside of each strand keeps the light trapped within the fiber. People can send just about any type of digital data through fiber-optics, though conversion for some signals may be necessary.

Fiber optic cable is replacing the standard copper wire of the local telephone company in many high tech uses.
Fiber optic cable is replacing the standard copper wire of the local telephone company in many high tech uses.

Telecommunications Applications

Telephones and Internet signals are often transmitted through fiber-optics. Companies simply convert phone audio signals into digital information, which can then be sent as light transmissions through the fibers. Many services convert the data into a binary signal of ones and zeroes, which they relay through pulses of light. Once a phone or other device receives the signal, it converts it back into audio information that the listener on the other end hears. Internet providers transmit data in much the same way, with computers converting digital signals into visible or auditory output.

Uses in Medicine

In 1930, a German student named Heinrich Lamm demonstrated how fiber-optics could be used to examine internal body parts. Since the images were unclear, however, he did not receive a patent for his invention. Additional developments have made optical fibers ideal for cameras and other devices used by medical professionals to view the internal organs of a patient. Since they are small and flexible, they can often reach areas that might otherwise be impossible to view without surgery.


Alexander Graham Bell, in 1880, demonstrated how light could be used to transfer sounds from one area to another. A few decades later, the first sets of bundled cables were developed, though they were not called "fiber-optics" at the time. In 1956, Narinder Kapany coined the term after bundling a few glass rods together. He then demonstrated that these rods could project light without leaking at any point, as long as they were wrapped or coated in a dark material.

By 1960, Dr. Charles Kao realized the potential of fiber-optics. He suggested that they could be used for fast, clear communications. In the 1970s, a company called CorningĀ® Glass created the first optical fiber made entirely of thin strands of glass. This led to Bell Telephone using these fibers to make telephone cables that could transmit crystal clear conversations from one side of the US to the other.

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Discussion Comments


How is an optical fiber better than an electric cable?


Please humor me. I really need to know about the use of fiber optics with taking video. A friend (yes, really a friend not me) recently told me she was sure her last boyfriend -- a real shady guy -- was spying on her through the use of fiber optic cameras. She pointed out pinhole marks in her ceiling of her room. I acted like she knew what she was talking about.

Later, though, I questioned myself if she really knew what she was talking about. I think someone is telling her tall tales. Could it be possible?


what did we use before fiber optics? that was what i wanted to look for.


What is used to convert the digital signals received through the fiber optics into a picture on your pc?


How can light be used as a fiber optic?


i want to know how light can travel through sound.


what are the problems related to fiber optics?


Is it possible to buy small bundles of broken optic fiber both in glass and plastic (two bundles brief). The length of each one shouldn't be more than four feet long and how many depends on the price and the availability. Can you refer me at least?


A voice is not passed through light. the light simply sends signals that are then converted into sound. this is why people sound different on telephones than they do in real life too. hope i helped.


i want to know how voice is passed through light.


if you know that laser emits light so 1,0 bits are used to turn it on or off. When digital data is 1 laser is on and when it is 0 laser is off, so a format of light is generated according to 0 and 1 bits and this way the digital signal is converted to light.


I want to ask how digital signals are converted into light and then how again they converted into digital signals on the receiver end? --sadaf


To send telephone conversations through a fiber optic cable, analog voice signals are

translated into digital signals.

A laser at one end of the pipe switches on and off to send

each bit. Modern fiber systems with a single laser can transmit billions of bits per second --

the laser can turn on and off several billions of times per second.

The newest systems use

multiple lasers with different colors to fit multiple signals into the same fiber.

that means the flow chart become:

sound--->electrical signal-->digital signal-->light-->[transmitted through fiber]


Digital signals are converted into bursts of light (usually laser or LED). At the receiving end, the bursts of light are converted back into digital data, and fed into a device.


i think there is a mechanism to convert sound into digital signals before passing them.


Where can I find a map of Fiber Optic lines through a given area?


There are codes 4 every sound, to answer your question.


I want to ask that it is understandable that from optical fiber light is passed because of the thin glass rods but how sound is passed??

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