Fibre Optic Cable, today's data communications media.

Thanks to the internet, this existing technology allows us to communicate everywhere in the world without any hassles.

The force that makes such an incredible job possible is fibre optic cable.

Fibre Optic Cable

In the late ’60s, UK-based Chinese physicist and engineer Dr. Charles Kuen-Kao first pointed out the impurities in the glass used in fibre optic cables. Moreover, fibre optic cable was only able to carry television and telephone signals. Measuring light pulses for just under 20 metres before almost all the light dissipated.

However, by the year 1970, scientists had come up with a new 805-metre long ultrapure fibre optic cable.  

Optic cables then, which looked more like fishing lines, were the key behind the production of biomedical informatics, innumerable broadband communication, and many other digital applications.

By the year 2009, researchers assumed that if placed all together, all fibre optic cables would constitute a length of no less than approx 966km.

How Does a Fibre Optic Cable Work?

A fibre optic cable sends coded information via a beam of light either through a plastic pipe or glass. Each fibre optic cable comes with super thin strands of plastic or glass, which are also known as optical fibres.

The standard length of each cable could be about two strands to several hundred in length. A strand size is no more than one-tenth of the width of a human hair. The strand can transmit 25,000 telephone calls. Thus, a cable containing hundreds of strands has the capacity to carry millions of calls at a time.   

Each photon or light particle works like a bobsled which bounces back and forth off the walls of the cable pipe. Any light leakage is prevented by ensuring a shallow angle of 42 degrees at the edges of a glass pipe, this is enough to fragment the light back into the pipe.

Scientists define the entire term as internal reflection.

Fibre Optic Cable total internal reflection

The light travels through the core of the cable. A second layer of glass called "the cladding" is wrapped around the outside of the core. The cladding makes sure that the light signals always remain inside the core. 


What Are Some Common Types of Fibre Optic Cables?

To answer this we need to understand the way light travels in fibre optic cable. Modes are the way for a light beam to travel down a fibre.

One of these modes goes straight through the middle, while another bounces down the fibre from narrow angles. In the same way, other modes also bounce down, but at different angles. 

The commonest type is the single-mode. The ultra-thin core, which is about 5-10 microns, sends signals straight down the middle without interrupting the cladding.

Telephone, internet, and cable TV signals are transmitted using single-mode fibres. These types of fibre optic cables can cover up to 97 kilometres.  

Multi-mode cable is another type of fibre optic cable. Each fibre in a multi-mode cable is about 10 times larger than that of single-mode cables. Their only setback is that they cover only a short distance. They are, however, widely used in computer networks.


How are Fibre Optic Cables made?

Despite the fragility of glass, glass fibres are made to be tough. A glass rod is pulled to produce most optical fibres at a heat level where it melts. It features a diameter of a few centimetres and a length of 1 metre, which is turned into a diameter of 125 micrometres and a length of several kilometres.   

Each of these fibres is wound together to make a thicker strand.


Fibre Optic Cable requires caution when used in an openly accessible environment.

It is commonly used in laboratories for research purposes and industrial assembly plants.