How Fibre Optics Work

The basic technology behind fibre optics is rather simple, when it comes down to it.


It all starts with the transmitter. Positioned close to the fibre, this produces light signals and flashes the light into the fibre.

Optical Fibre

This is where fibre optics gets its name. Each fibre is a long, thin strand of pure glass. It’s about the size of a human hair. Despite it’s tiny size, there are three different parts to each individual fibre.

  • The core is in the direct centre of the fibre, where the light travels.
  • The cladding is the outer material that bounces the light back into the core as it travels down the fibre.
  • The buffer coating is made of plastic and protects the fibre from water and other damage.

Each of these fibres are grouped in hundreds and hundreds into bundles called optical cables. Like each individual fibre, these cables are encased in a plastic jacket.

After the light is transmitted into the fibre, the fibre works as a mirror to reflect and convey the light-and therefore, the information-across great distances, even when it’s not a straight line. This is called total internal reflection. Because the cladding doesn’t absorb any light, it can go very far. However, if the glass is impure, the light can degrade.

Optical Regenerator

The next step solves the problem of degraded light. The regenerator boosts the light signals over longer distances and brings the power of the light back to normal speed. Each fibre has a special coating called doping that has energy from a laser. The laser energy boosts the weak light signal

Optical Receiver

Finally, the light comes to the end of its path and is decoded by the receiver. As you can see, it’s a pretty simple process. Only a few short parts and a few short steps, and it makes your internet all the faster!