Question

Optical fibre are based on

• A. total internal reflection
• B. less scattering
• C. refraction
• D. less absorption coefficient.

Answer 1

The Correct Option is A

Optical fibres are sophisticated tools extensively used in various applications, most notably in telecommunications and medical equipment. The correct functioning principle underlying optical fibres is crucial to understand. Let's delve into the options provided to find out why the correct answer is total internal reflection.

1. Total Internal Reflection:
   • Optical fibres function based on the principle of total internal reflection. This occurs when light traveling through a medium (with a higher refractive index) is reflected entirely within the medium instead of passing through into another medium (with a lower refractive index).
   • The core of the optical fibre has a higher refractive index than the surrounding material, called cladding. This difference in refractive index ensures that light entering at a suitable angle remains trapped inside the core, reflecting internally.
   • This mechanism allows light to travel over long distances with minimal loss, making optical fibres efficient for signal transmission.
2. Less Scattering:
   • Scattering in fibres causes light signals to disperse, leading to signal degradation. Although minimizing scattering is important for improving performance, the fundamental principle is not based on scattering.
3. Refraction:
   • Refraction involves bending of light as it passes from one medium to another. While initial input of light into the fibre involves refraction, it is not the key principle that keeps the light confined within the fibre.
4. Less Absorption Coefficient:
   • While lower absorption coefficients are beneficial, they relate to the attenuation of signals rather than the fundamental principle allowing light to travel through optical fibres.

In conclusion, the optical fibre utilizes total internal reflection to maintain light signals within the core, based on the refractive index difference between the core and the cladding. This principle ensures efficient, long-distance communication with minimal signal loss, which is why the correct answer is total internal reflection.