Basic Unit of Outdoor Optical Cable

The basic unit of an outdoor optical cable is the optical fiber, a thin strand of glass or plastic that transmits light signals.

Core Component

The optical fiber serves as the fundamental unit of outdoor optical cables. It is a thin strand, often as fine as a human hair, made of high-purity glass or plastic, designed to carry data in the form of light pulses at extremely high speeds and bandwidths far exceeding traditional copper cables. Each fiber consists of a core and cladding, where the core guides light through total internal reflection, and the cladding protects the optical properties of the fiber.

Cable Structure

In outdoor applications, the optical fiber is typically enclosed in additional protective layers to withstand harsh environmental conditions such as UV radiation, temperature fluctuations, moisture, and mechanical stress. A typical outdoor optical cable includes: Filling Material: Water-blocking gel or dry-block materials to prevent moisture penetration. Reinforcement: Steel wires or aramid fibers (e.g., Kevlar) to provide tensile strength and mechanical durability.

Sheath: Polyethylene (PE) or flame-retardant materials (LSZH) to protect the internal structure from environmental hazards.

Types of Outdoor Optical Cables

Outdoor optical cables can be designed in various structures: Central Tube Optical Cable: Multiple fibers are placed in a central high-strength plastic tube, surrounded by reinforcement and a protective sheath. Gel filling inside the tube provides waterproofing and buffering. Stranded Optical Cable: Multiple loose tubes are helically arranged around a central reinforcement, offering high tensile strength and large fiber capacity, suitable for long-distance trunk lines.

Summary

While outdoor optical cables include multiple layers for protection and reinforcement, the optical fiber itself remains the basic unit, as it is the element responsible for transmitting light signals. All other components, such as tubes, gel, reinforcement, and sheathing, serve to protect and support the fiber in challenging outdoor environments.