Are fiber optic cables the best to use for internet use?

There are two main types of optical fibre used in telecommunications Multimode which is cheap and can only propagate light relatively short distances. This is now only commonly used within buildings. Single mode fibre has a graduated refractive index, this means it is manufactured with a varying density from the outside of the fibre to the centre. This makes the light only bounce around in the middle of the already very thin fibre. The end result is far greater propogation distances, but it is more expensive to manufacture. This type of optical fibre is used between buildings, even in different cities.