Bitesize has changed! We're updating subjects as fast as we can. Visit our new site to find Bitesize guides and clips - and tell us what you think!
Print

Science

Sending information

Page:

  1. 1
  2. 2
  3. 3
  1. Next

Optical fibres can carry information coded in light or infrared signals. Optical fibres can carry more information than an ordinary cable of the same diameter.

Analogue signals vary continuously in amplitude [amplitude: The maximum height of a wave, measured from the mid-point of its vibration. ], frequency [frequency: The number of repetitions per second of a wave. The unit of frequency is the hertz, 'Hz'. ] or both. Digital signals are a series of pulses with two states – on or off. Digital signals carry more information per second than analogue signals, and they maintain their quality better over long distances.

Optical fibres

Optical fibres

An optical fibre is a thin rod of high-quality glass. Very little light is absorbed by the glass. Light getting in at one end undergoes repeated total internal reflection, even when the fibre is bent, and emerges at the other end.

Information such as computer data and telephone calls can be converted into electrical signals. These can be carried through cables, or transmitted as microwaves or radio waves. However, the information can also be converted into either visible light signals or infrared signals, and transmitted by optical fibres.

Optical fibres can carry more information than an ordinary cable of the same thickness. The signals in optical fibres do not weaken as much over long distances as the signals in ordinary cables.

the light ray enters the fibre at one end and is reflected out at the other end

Optical fibre

Page:

  1. 1
  2. 2
  3. 3
  1. Next

Back to Radiation and the Universe index

BBC © 2014 The BBC is not responsible for the content of external sites. Read more.

This page is best viewed in an up-to-date web browser with style sheets (CSS) enabled. While you will be able to view the content of this page in your current browser, you will not be able to get the full visual experience. Please consider upgrading your browser software or enabling style sheets (CSS) if you are able to do so.