Optical fibres transmit light because of

Optical fibers transmit light due to a principle known as total internal reflection. Here are the steps explaining how it works:

1. An optical fiber is made up of a core and a cladding, each made from slightly different types of glass or plastic. The core is the inner part where the light travels, and the cladding is the outer part.

2. The core has a higher refractive index than the cladding. This means that light travels slower in the core than in the cladding.

3. When light enters the fiber, it is directed at an angle to the boundary between the core and the cladding. If this angle is greater than a certain critical angle, the light will be totally internally reflected back into the core.

4. This total internal reflection causes the light to bounce back and forth off the boundary as it travels along the fiber. This keeps the light trapped inside the core.

5. The light can travel great distances along the fiber with very little loss of intensity. This is why optical fibers are used to transmit data over long distances.

6. At the end of the fiber, the light signals are converted back into electrical signals that can be understood by electronic devices.