Two sections of the optical cable

The two primary sections of an optical cable are the core and the cladding, which together guide and contain light for data transmission.CoreThe core is the innermost part of the optical fiber and is responsible for carrying light signals. It is typically made of high-purity glass (silicon dioxide) or sometimes plastic, and its diameter varies depending on the fiber type: single-mode fibers usually have a core diameter of 8–10 microns, while multimode fibers range from 50–62.5 microns . The core's refractive index is higher than that of the surrounding cladding, which allows light to be confined within the core through total internal reflection .CladdingSurrounding the core is the cladding, a layer of material with a slightly lower refractive index than the core. The cladding ensures that light remains within the core by reflecting it back whenever it reaches the interface between the core and cladding. This layer is crucial for maintaining signal integrity and minimizing loss over long distances . The cladding is usually coated with a protective polymer layer to prevent physical damage and reduce microbending losses .Additional Protective LayersWhile the core and cladding are the essential sections for light transmission, optical fibers are often encased in additional layers for mechanical protection. These include coatings, strengthening fibers (such as Kevlar), and an outer jacket that shields the fiber from environmental damage, moisture, and tension . These layers do not affect the optical properties but are critical for durability and installation. Together, the core and cladding form the functional heart of the optical cable, enabling efficient light transmission, while the surrounding protective layers ensure the fiber's longevity and reliability in various applications.