What are Fibre Optics?

What are Fibre Optics?

What are Fibre Optics?

 

Fibre optics are the materials used to send information in the form of light down a glass or plastic pipe. First developed and utilised in the 1950s to assist medical doctors in seeing inside a human body, these cables soon advanced and the technology was improved upon by the engineers at the time. In the 1960s, they began using fibre optics to transmit telephone calls at the speed of light (around 300, 000 km/second).

A fibre optic cable is composed of extremely thin strands of glass (fused silica) or plastic which are known as optical fibres. In a single cable, there is the capability to house as few as two strands and as many as a several hundred strands of optical fibres. The thickness of each strand is around a tenth as thick as a human hair and can carry as many as 25, 000 telephone calls entirely through optical (light based) technology meaning that an entire fibre optic cable can easily carry several million calls.

As light travels down the fibre-optic cable, the photons continuously bounce off the walls at extremely high speeds. In order to keep the light inside of the pipe, it bounces off the edges at shallow angles (less than 42 degrees) and reflects back again. This is known as total internal reflection.

The cable’s structure also allows the light to be kept inside. This structure is made up of two separate parts: the core (found in the middle of the cable and the area where the light travels through) and the cladding (the layer found housing the core used to keep the light signals inside). Both the core and the cladding are made up of different types of glass which allow for the cladding to have a lower refractive index when compared to the core.