Optical fibres, though bent in any manner, allows light to pass through. What is the inference that one can draw from it ?

Optical fibres function as 'light pipes' that guide light through a core material, even when the fibre is bent or curved. This transmission is made possible by the principle of total internal reflection (TIR). When light enters the core and strikes the boundary between the core and the cladding at an angle greater than the critical angle, it is reflected entirely back into the core rather than refracting out. This process repeats multiple times along the length of the fibre, allowing the light to follow the physical path of the cable regardless of its shape. While light generally travels in straight lines in a uniform medium, the repeated reflections at the internal boundaries of the fibre allow it to navigate bends without significant loss of signal. Ductility is a mechanical property of the material and does not explain the optical mechanism of light transmission.

Sources

1. [1] Science , class X (NCERT 2025 ed.) > Chapter 9: Light – Reflection and Refraction > p. 134