Fiber-optic cable
Imagine a very long, clear strand of hair made entirely of transparent glass or plastic. Now imagine it carrying information at the speed of light over extremely long distances.
Add an outer coating to prevent light from escaping, bundle a group of the strands together, and you have a fibre-optic cable.
Fibre-optic cables use light to transmit information over great distances at high speed. They are used widely in telecommunications because of their many advantages. For example they are smaller, cheaper and can carry more information with less 'degradation' or signal loss than other kinds of cables. Today these cables are found in the backbone of the internet and most international telephone networks.
The fibres used in long-distance telecommunications are made of very pure glass rather than plastic, because glass does not weaken the power of light signals the way plastic does. For shorter distances, plastic is often used.
For very short distances, fibre-optics are not always the best choice. Cables such as copper wires and coaxial cable, which transit information using electricity, can use cheaper transmission and reception equipment, and are easier to join together or splice into new circuits. Often times in very short distances, there is very little need for the speed and huge volumes of transmission that fibre optic cables can offer.
A cross section of an optical fibre.
Source: Bob Mellish
|