How is light able to carry data in fibre optic internet connections?
As per the example in the video you'll watch below, fibre optics carry data pretty much in the same way people use a light source, such as a flashlight, to communicate to one another by means of Morse code. The light in the fibre optics pulse light waves thousands of times per second, which in the receiving end is decoded into the familiar matrix of computer code.
Probably the most important question is how do you send light over thousands of kilometres around the world and still manage to extract information from it? Just by the sheer nature of light, we know that light loses intensity over distance, and it becomes increasingly more scattered as well. Well, to solve this, fibre optics have to be specially designed in order to make sure that the data is still readable. The core and outer core (cladding) are specially, chemically designed to be as reflective as possible to ensure that the data can travel over great distances around the planet without getting too scattered, but this still does occur.
So, what engineers have developed on modern cables is to install a series of amplifiers which are able to take scattered data, clean up the code, make the signal stronger than ever, and continue sending it on its way down the fibre optic line.
Take a look at the video below by YouTube channel, Tech Quickie, on How Does Light Carry Data?