Fiber Optics
There are two kinds of fibre optics. The single-mode fibre optic is used for high speed and long distance transmissions because they have extremely tiny cores and they accept light only along the axis of the fibres. Tiny lasers send light directly into the fibre optic where there are low-loss connectors used to join the fibres within the system without substantially degrading the light signal. Then there are multi-mode which have much larger cores and accept light from a variety of angles and can use more types of light sources. Multi-mode fibre optics also use less expensive connectors, but cannot be used over long distances.
Fibre optics is widely used in communication systems. They are far superior to systems using traditional copper cables. Fibre optic communication systems are installed in large networks of fibre optic bundles all around the world and even under the oceans.