subject: Data Transmitted By Light Pulses? Unbelievable! [print this page] When the early inventors first transmitted electricity through wire, they could not possibly have imagined that only 100 or so years later, this invention would be made obsolete by fibre optics which would see data hurtling through hair-thin glass at the speed of light.
It's difficult to envisage just how the communications industry could have had advancement to where it is today if it hadn't had the advent of fibre optics. The none-too-distant future will see the gradual demise of the old, and now inadequate hardwired technology which is unable to transfer data at the speeds now demanded by business, industry and private users.
While the term, fibre optics, has become a familiar part of the language to most, understanding how it manages to whiz data around the globe at blistering speeds is generally a stretch for the average person, especially those of us who didn't pay attention in Science classes. This brief explanation will hopefully provide some insight into how fibre optic cabling has changed the way we communicate.
What is a Fibre Optic Cable?
This type of cable transmits information using light instead of electricity. It has a core of one or more extremely thin strands of optic quality glass contained within a sheath which provides a pathway through which light can flow. These strands are so thin that millions of them can be bundled together, allowing the transmission of huge amounts of digital information over long distances at the speed of light.
The fibres themselves are either single-mode, meaning only one propagation path is available, or multi-mode which, as the name suggests, supports multiple pathways.
The fibres run through the core of the cable which is enclosed in cladding to refract light inward. Surrounding the cladding is a buffer of several layers of plastic to absorb impact and protect the core from damage. Additional protection can be added by the use of strength members which are usually made of fibreglass or steel. The entire cable is then surrounded by a jacket or outer covering to keep out moisture.
How does a Fibre Optic Cable work?
In order for the transmission of data signals to go through, completed cables must be connected to an optical transmitter. This is where electrical and analogue signals are made into light signals. The data is relayed to an optical receiver which can accept the light signal, and then converts the data back into the original format.
The cabling can be run over vast distances and retain the speed and absolute integrity of the transmission data. They are able to bend and twist, without distorting the data, as the light signals bounce off the inside of the fibres. The cables are also not affected by electrical interference.
When first introduced over 20 years ago, fibre optic cables were expensive and as a result their use was limited, but with both supply and demand firmly established and prices continuing to drop, companies such as CLP (Cable Laying Products) are able to manufacture and supply these products to the cable laying industry.
