What is a Fiber Optic Cable?

Answer 1

A simple definition of fiber optics is the transmission or sending of light signals through glass fibers. A fiber optic cable is a cable made of hundreds of optical fibers bound together. When arranged in this manner, a fiber optic cable can transmit large amounts of information over long distances at the speed of light.

A single fiber optic filament that is used to send telecommunication information is made of pure glass. Sometimes plastic fibers are used in a fiber optical device, but plastic fibers tend to be useful only for much shorter distances and carry light toward the red end of the visible spectrum.

A single optic fiber is smaller in diameter than a human hair, but even that is large enough to carry many pulses or bundles of light. As a light beam enters on end of the fiber, it will bounce along inside the glass core. The outside of the tiny core is actually another layer of glass cladding with a slightly different density. The change in density acts like a mirror and reflects all the light back into the core. Because the cladding does not absorb any light from the core, all the light is being reflected back into the core and none of it escapes to the outside of the cable.

This complete reflection is known as total internal reflection. If you have ever stood outside a fish tank and viewed it at an angle so that instead of looking through the glass, you were seeing an image reflected as if the clear glass side had turned into a mirror, you will have an idea of how the light stays inside fish tank or optical cable. This principle of total internal reflection is the reason that the light wave can travel great distances without getting lost..

On the very outside of the bundle of fiber cores and cladding is a buffering coating that will protect the core and cladding from abrasions, moisture, and other things that could damage the cable. Because the information these cables carry is in light waves, they are safer than high voltage metal wires.

Answer 2

A fiber optic cable is a cable that carries a beam of light along its length, transmitting data by the presence or absence of light.