MCQ Detailed View

Optical fibers are thin strands of glass or plastic that are used to transmit light signals over long distances. These fibers are commonly used in internet cables, telephone systems, and medical instruments like endoscopes.

The structure of an optical fiber has two main parts: the core and the cladding. The core is the inner part where the light travels, while the cladding surrounds the core and has a lower refractive index.

When light enters the fiber at a certain angle, it gets trapped inside the core. This happens because of a phenomenon called total internal reflection. Total internal reflection occurs when light travels from a medium with a higher refractive index (the core) to a medium with a lower refractive index (the cladding), and hits the boundary at an angle greater than the critical angle. Instead of passing through the boundary, the light reflects back entirely into the core. This process continues repeatedly, guiding the light through the fiber without much loss.

This principle allows optical fibers to transmit data as light pulses with high speed and low interference. Total internal reflection is different from refraction, where light bends when passing between materials. It is also not diffraction, which involves spreading of light around obstacles.

Understanding total internal reflection is important in the field of physics, especially in optics. It helps explain how modern communication systems work and why optical fibers are efficient tools for fast, reliable data transmission.