Write a note on optical fibre.

Explanation

Transmitting signals through optical fibres is possible due to the phenomenon of total internal reflection. Optical fibres consists of inner part called and outer part called cladding (or) sleeving. The refractive index of the material of the core must be higher than that of the cadding for total internal reflectio to happen. Singnal in the form of light is made of incident inside the core - cladding boundary at an angle greater than the critical angle. Hence, it undergoes repeated total internal reflections along the lenght of the fibre without undergoing any refraction.