What material is primarily used as the core in fiber optic cables?

Question

Question

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RRB JE ECE 22 Apr 2025 Shift 1 CBT 2 Official Paper

Answer 1

Optical fibers are cylindrical solid glass material acting as waveguides made of two concentric layers of very pure glass.
The core (the interior layer) with refractive index n1 serves as the medium for light propagation, while the cladding (the exterior layer) has a lower refractive index n2 where n1 > n2 assuring that light rays are reflected to the core.
Since the cladding does not absorb any light from the core, the light wave can travel great distances.

Working:

The working principle of optical fibers is Total Internal Reflection.
Optical fiber mostly used for communication purposes with negligible loss of energy.
The “Total Internal Reflection” of light is the boundary between transparent media of two different refractive indices.
At present, Optical fiber cables are used for communication like sending images, voice messages, etc.
The designing of this cable is done with Plastic or glass so that data can be transmitted effectively and quickly than other modes of communications.