Outdoor Fiber Optic Technology : The Link that Connects the World

2023-08-16

What is Outdoor Fiber Optic Cable?

Outdoor fiber optic cable is a type of optical fiber cable used for communication transmission. It features an additional protective layer known as armor or metal sheath, which provides physical protection to the fiber optics, making them more durable and capable of functioning in harsh environmental conditions.

1.Main Components

Outdoor fiber optic cables generally consist of bare fibers, loose tubes, water-blocking materials, strength members, and outer sheaths. They come in various structures, including central loose tube, layer-stranded, and skeleton designs.

Bare fiber refers to the original 250μm diameter optical fiber, typically consisting of core, cladding, and coating layers. Different types of bare fibers have varying core sizes; for instance, single-mode OS2 fiber is usually 9μm, while multi-mode OM2/OM3/OM4/OM5 fibers are 50μm, and OM1 multi-mode fiber is 62.5μm. The exterior of bare fibers is often color-coded to distinguish between different core fibers.

Loose tubes are typically made from high-strength engineering plastic, such as PBT, and are used to house the bare fibers. They provide protection and are filled with water-blocking gel to prevent water ingress that could damage the fibers. The gel also acts as a cushion, safeguarding the fibers from impacts. The loose tube process is a critical step in outdoor fiber optic cable production to ensure sufficient fiber slack.

Water-blocking materials include cable water-blocking grease, water-blocking yarn, or water-blocking powder. Water-blocking grease is commonly used to enhance the overall water-blocking capability of the cable.

Strength members come in metallic and non-metallic forms. Metallic strength members are often made from phosphated steel wires, aluminum tapes, or steel tapes, while non-metallic ones are primarily composed of FRP materials. Both types must provide sufficient mechanical strength to meet standard requirements, including tensile, bending, impact, and torsion resistance.

Outer sheaths need to consider environmental factors such as waterproofing, UV resistance, and weatherability. Therefore, black PE material is commonly used due to its excellent physical and chemical properties, ensuring suitability for outdoor installation.

2.Features and Applications

Excellent Fire Resistance: The presence of a metal sheath gives outdoor fiber optic cables exceptional fire resistance. The metal material can withstand high temperatures and effectively isolate flames, reducing the impact of fires on communication systems.

Long-Distance Transmission: Enhanced by its physical protection and interference resistance, outdoor fiber optic cables support longer-distance optical signal transmission. This feature makes them particularly useful for scenarios requiring extensive data transmission.

High Security: Outdoor fiber optic cables can resist physical attacks and damage from external factors. As a result, they find widespread use in environments with stringent network security requirements, such as military bases and government institutions, ensuring network security and reliability.

3.Advantages Over Regular Fiber Cables

1) Robust Physical Protection: The metal sheath of outdoor fiber optic cables effectively shields the fiber cores from external physical damage. It prevents the cable from being crushed, stretched, or cut, providing enhanced durability and stability.

2) Strong Interference Resistance: The metal sheath also acts as electromagnetic shielding, preventing external electromagnetic interference from affecting optical signal transmission and improving interference resistance.

3) Suitability for Harsh Environments: Outdoor fiber optic cables can be used in various harsh environments, including extreme conditions like high and low temperatures, humidity, and corrosion. This makes them suitable for outdoor cabling, underwater communication, industrial, and military applications.

4) Extra Mechanical Protection: The metal sheath can withstand substantial mechanical pressure and tension, safeguarding the fibers from external forces and reducing the risk of cable damage.

It's important to note that compared to regular fiber cables, outdoor fiber optic cables might have higher costs and installation complexity. Due to the presence of the metal sheath, outdoor cables are relatively bulkier and less flexible, so choosing the appropriate cable type is crucial in specific situations.

Due to their strong physical protection, interference resistance, adaptability to harsh environments, outdoor fiber optic cables have become the preferred choice for many critical applications, providing vital support for reliable communication transmission.