Optical fibre works on the principle of:

Concept:

Total Internal reflection: The total reflection of light from a higher refractive index medium back to its normal medium at an angle more than a critical angle is known as total internal reflection.

It always happens when light travels from denser medium to rarer medium.

At critical angle θ_c it makes 90⁰ angles with normal separating the two media.

Sin i_c = n₂/n₁ [where n₂ = rarer medium, n₁ = denser medium]

• Optical fibre: It is a very thin fibre made of glass and plastic having a radius of the order of a micrometre (10^-6 m).
  • It works on the principle of Total Internal Reflection.
  • It is lightweight, fast, and useful for long-distance data and light transmission with very few losses.
  • A bundle of such thin fibres forms a light pipe.

• Refraction: When a ray of light passes from one medium to another it suffers a change in direction at the boundary of two media is called refraction.
• The change in direction because the speed of light travels at different speeds in different mediums.
• Refractive Index of a medium defines that it is denser or rarer
• Refractive Index = Speed of light in Vacuum /speed of light in that medium.

Explanation:

As explained above, the optical fibre works on the principle of Total Internal Reflection (TIR) for high-speed data transfer.