What is Fibre Optic cable?

An Optical Fibre Cable consists of a solid rod of pure glass enclosed inside a 'shield'. The fibre is protected by the outer, which also helps prevent light loss.

Optical fibre sends millions of pulses of light every second, allowing the transfer of more information, for longer distances, in less time than conventional copper media. It is not affected by electricity, water or radio interference and is not a conductor, therefore is safe to run externally. Another positive feature of Optical Fibre is that it is a very secure media.

Optical Fibre is rated as core and outer (cladding) size, for example, 62.5/125 has a core diameter of 62.5 microns and a outer diameter of 125microns. Optical Fibre is available in two formats for the structured cabling system - multi-mode and single-mode.

Multi-mode (MM) has a central core of typically 62.5 or 50 microns, surrounded by a larger outer cladding, typically 125 microns. This mode is most frequently used as a network spine or to link building or networks.

Single-mode (SM) has a central core of typically 8 - 10 microns, surrounded by a larger outer cladding, typically 125 microns. Most commonly, used for long distances and high speeds by national carriers, for example, BT.

The multi-mode format is predominately used as the preferred fibre due to the use of cheaper LED transmitters but single-mode (as a backbone) can be offered as an alternative if very high bandwidth applications are to be used in the future.