Question

What is optical fibre and its principle?

Answer 1

Optical Fiber:

An optical fiber is a thin, flexible strand of glass or plastic that carries light signals. It's used in communication systems to transmit data over long distances, like in internet connections, telephone lines, or cable TV.

Principle of Optical Fiber:

The main principle behind optical fibers is called Total Internal Reflection. Here's how it works:

1. Core and Cladding: Optical fibers consist of two main parts:
   

   - Core: The central part, usually made of glass or plastic, where light travels.
   - Cladding: A layer surrounding the core, made of a material with a lower refractive index than the core.

1. Refraction and Reflection: When light is injected into the core at a certain angle, it travels through the fiber by bouncing off the boundary between the core and cladding.
   

1. Total Internal Reflection: The light is constantly reflected within the core due to the principle of total internal reflection. This happens when the light hits the boundary at a steep angle, greater than the critical angle (which depends on the materials' refractive indexes). This reflection keeps the light inside the core, preventing it from escaping into the cladding.
   

1. Low Loss Transmission: Because the light is contained within the core, it can travel long distances without much signal loss, making optical fibers ideal for high-speed data transmission.
   

In short, optical fibers work by keeping light inside the core using total internal reflection, allowing it to travel over long distances with minimal signal loss, making them ideal for high-speed communication.