How Does Fibre Optics Work?

We all know the hype about fibre over the past few years and we all know its fast but how does it work?

South Africa has been advancing quite quickly in terms of the fibre connectivity that has been rolled out over the past 5 years and that continues to be rolled our in various business, industrial and residential areas. Fibre optics which is used for data, voice and video communication is currently the most demanded highspeed internet service in South Africa, we all know that but, how does fibre optics work?

Fibre optics or optical fibres are long, thin strands of pure glass measuring about the diameter of a human hair. Optical fibres are bundled together into what is called optical cables that are used to transmit light signals over long distances. If you had to examine a single optical cable you would notice that it is made up of three parts:

Core – the thin glass centre of the fibre where light travels through
Cladding – outer optical material that surrounds the core that reflects the light back into the core
Buffer Coating  – Plastic coating that protects the fibre from damage and moisture

How does Fibre Optics work?

The fibre optics system works using what we can break up into three parts being the transmitter, the optical regenerator and the optical receiver. The transmitter is close to the fibre and has a lens to focus light into the fibre. A message from the network or internal device will be sent to the transmitter in data form and then be transmitted by the transmitter using light in a similar way to the how navy ships communicate in morse code using the flashlight.

Because of the distance that the light travels across the fibre, there are sections within the fibre that are spliced in order to boost the degraded light signals. These are known as optical regenerators which consists of optical fibres with a special coating known as a dope. When the degraded light signals reach the doped coating, the doped molecules emit a new and stronger light signal basically amplifying the degraded light in order for it to be carried further on.

The last part of the optical fibre system is the optical receiver which receives the message and then takes the incoming light signal, decodes them and send them in an electrical signal to the other users computer, TV or telephone.