An optical fibre cable is a crucial technology for high-speed data transmission, consisting of multiple layers, each with a specific function. Understanding these parts is essential to comprehend how data travels through the cable and how it is protected.

Optical Fibre Cable Structure Explained

An optical fibre cable typically comprises three main parts that work together to transmit and protect light signals. These parts are the core, the cladding, and the buffer coating. Let's delve into the role of each component:

• Core: This is the innermost part of the optical fibre cable. It is a thin strand of highly pure glass or plastic through which light signals travel. The core is the primary medium for light propagation.
• Cladding: Surrounding the core is a layer called the cladding. The cladding is also made of glass or plastic but has a slightly lower refractive index than the core. Its main function is to reflect light back into the core, ensuring that the light signals travel along the fibre without escaping. This phenomenon is known as total internal reflection.
• Buffer Coating: This is the outermost protective layer of the optical fibre. It is usually made of a tough plastic material. The primary purpose of the buffer coating is to shield the delicate core and cladding from physical damage, moisture, and other environmental factors. It provides mechanical protection, making the fibre more robust and resistant to bending, crushing, and abrasion.

Optical Fibre Protective Coating Identification

The question specifically asks to identify the "protective outer coating" of an optical fibre cable from the given options. Let's analyze each option based on the functions discussed:

• Fibre: This is a general term often used to refer to the core and cladding together, which are the light-carrying elements. It is not specifically the outer protective layer.
• Buffer coating: As explained, the buffer coating is precisely the protective outer layer that safeguards the core and cladding from external harm. Its robust nature is designed for this very purpose.
• Cladding: While integral to light transmission by reflecting light, the cladding surrounds the core and is itself protected by the buffer coating. It is not the outermost protective layer.
• Core: This is the central part that transmits light. It is the most delicate component and is located at the very centre of the fibre, not on the outside.

Based on this analysis, the component that serves as the protective outer coating of an optical fibre cable is the buffer coating.