Question

In optical fibres we reflect light by the use of total internal reflection (TIR). I know there will be some energy loss in optical fibres if we use mirrors but why there isn't significant loss in TIR? (some light must be absorbed)

Answer 1

Total internal reflection occurs when the incident angle in a medium is greater than the critical angle, resulting in all the light being reflected back into that medium. In optical fibers, the cladding and the varying refractive index help prevent significant energy loss and guide more light along the fiber through total internal reflection.

Step-by-step explanation:

Total internal reflection is a phenomenon that occurs at the boundary between two mediums, such that if the incident angle in the first medium is greater than the critical angle, then all the light is reflected back into that medium. In optical fibers, the cladding prevents light from being transmitted between fibers in a bundle, reducing significant energy loss. Additionally, fiber optics are designed to have a varying refractive index, which allows more light to be guided along the fiber through total internal reflection.