Fibre optics:

The songs you hear on your transistor, or the pictures you  see on your TV are canied from the studios to your home on radiowaves. Telephone calls you make, on the other hand, are bansmitted by electric current flowing in copper wires. In-the recent  past,-new technologies have sppeared for transmitting various kinds of electric signals on glass fibres. This has been possible due to the advances in fibre optics  technology. Fibre optics is the technique of  transmitting light waves through glass wires as thin as human hair. These wires called optical fibres could be made of glass or transparent plastic, quartz, nylon or polystyrene. Opticalfibres are thin hair-like solid strands that carry light along their length, by a  process of multiple  total internal reflections (Fig). We will not go into the details of  the process. In this process  the beam of  light entering at one end is transmitted along  the fibre, without loss of intensity, whether the fibre  is straight or bent in a curve.