What is the material used for the manufacture of fiber optic cables?

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RRB ALP Electronics Mechanic 21 Jan 2019 Official Paper (Shift 3)

Answer 1

Fiber optic cable

F1 Vinanti Engineering 27.02.23 D3

A fiber optic cable consists of five main components: core, cladding, coating, strengthening fibers, and cable jacket.

1.) Core

The core of the fiber cable is made up of glass.
This is the physical medium that transports optical signals from an attached light source to a receiving device.
The core is a single continuous strand of high-purity glass or plastic whose diameter is measured in microns.
The larger the core, the more light the cable can carry, which correlates to a higher data transfer rate.

2.) Cladding

This is a thin layer that is extruded over the core and serves as the boundary that contains the light waves, enabling data to travel through the length of the fiber.

3.) Coating

This is a plastic coating over the cladding to reinforce the fiber core, help absorb shocks, and provide extra protection against excessive cable bends.
It does not have any effect on the optical waveguide properties.

4.) Strengthening fibers

These components help protect the core against crushing forces and excessive tension during installation.
The materials can range from Kevlar, to wire strands, to gel-filled sleeves.
Sometimes light-absorbing (“dark”) glass is added between the fibers, to prevent light that leaks out of one fiber from entering another. This reduces cross-talk between the fibers.

5.) Cable jacket

This is the outer layer, or sheathing, of the cable.
Its purpose is to protect the cable from environmental hazards, such as construction work, fishing gear, and even sharks, which are often attracted to the electrical fields created by signal conductors to repeaters.