The optical cable structure consists of several parts

An optical fiber cable consists of a core, cladding, coating, strengthening fibers, and an outer jacket, each designed to ensure efficient light transmission and mechanical protection.

Core

The core is the central part of the optical fiber where light signals travel. It is typically made of high-purity silica glass, though some fibers use plastic for short-range applications. The core's refractive index is higher than the surrounding cladding, enabling total internal reflection, which keeps light confined within the core for long-distance transmission. Core diameters vary: single-mode fibers usually have a 9-micron core, while multimode fibers range from 50 to 62.5 microns, affecting bandwidth and distance capabilities .

Cladding

Surrounding the core is the cladding, made of glass or plastic with a slightly lower refractive index than the core. This difference ensures that light reflects back into the core, minimizing signal loss. The cladding also provides a protective layer that maintains the optical properties of the core .

Coating

The coating or buffer layer encases the cladding, providing mechanical protection against bending, impacts, and environmental factors. Coating thickness typically ranges from 250 to 900 microns and helps prevent microbends or fractures that could degrade signal quality .

Strengthening Fibers

Strengthening fibers, often made of aramid yarns like Kevlar, are included to absorb tensile stress and protect the delicate core from stretching or crushing. These fibers are especially important in outdoor or long-distance installations where cables may experience tension .

Outer Jacket

The outer jacket is the external protective layer that shields the cable from moisture, abrasion, UV exposure, and other environmental hazards. Jacket materials vary depending on installation requirements, such as indoor, outdoor, or armored applications .

Summary

The combination of core, cladding, coating, strengthening fibers, and outer jacket ensures that optical fiber cables can transmit data efficiently over long distances while remaining durable and resistant to environmental and mechanical stresses. Understanding these components is essential for selecting the right fiber optic cable for specific applications .