Q.Which are the materials commonly used for fiber optic cables?

Optical fibre communication is a system that uses light, rather than electrical current or radio waves, as the carrier of the information being sent. The light travels through a thin, highly transparent "light pipe" or waveguide called a fibre-optic cable, usually made of glass or plastic — materials chosen because they let light pass with very little loss.

The great advantage of carrying information on light is bandwidth: where microwave links can carry a few hundred telephone conversations at once, a single light beam in a fibre can carry many thousands of signals simultaneously, giving an almost limitless information-carrying capacity when multiplexing is used. …