What is a Fiber Optic Cable?

A fiber optic cable is a high-speed cable type designed for data transmission via light signals. These cables contain very thin fiber cores made from glass or plastic. Data is transmitted through internal reflections of light along these cores. Compared to traditional copper cables, fiber optic cables offer much higher transmission speeds and are immune to electromagnetic interference.

Fiber cables are generally available in single loose tube or multi loose tube constructions. Single-tube cables are often preferred in small-scale installations, while multi-tube fiber cables are used in large-scale infrastructure projects. When considering the performance-to-price ratio of fiber optic cables, especially in extensive network projects, they provide significant cost advantages in the long term.

Where are Fiber Optic Cables Used?

Fiber optic cables are used in a wide range of applications. These include internet infrastructure, data centers, FTTH (Fiber To The Home) projects, industrial automation systems, government institutions, and military communication systems.

In recent years, the use of fiber cables in in-building network infrastructures has also increased. B2ca-rated fiber optic cables with halogen-free, low smoke outer sheaths are preferred in large commercial buildings, malls, hospitals, hotels, and government facilities due to their compliance with CPR regulations.

Outdoor fiber optic cables are typically manufactured with steel wire armor to withstand rodents, impacts, and physical stress. For aerial installations, fiber cables with messenger wire are commonly used.

How to Choose a Fiber Optic Cable?

Several technical factors must be considered when selecting a fiber optic cable. The most important are:

1. Cable Structure

Depending on the application, single-tube or multi-tube configurations may be preferred. Different mechanical protections are required for indoor versus underground applications. For example, armored fiber cables are often used for underground installations, while smaller, more flexible types are ideal for indoor routing.

2. Core Types (Fiber Types)

Fiber optic cables are available in two main types based on the type of light transmission and use case: multimode and singlemode.

Multimode Core Types (OM1, OM2, OM3, OM4, OM5):

Multimode fiber cables are typically used for short-range in-building networks. Their larger core diameters support multiple light modes.

• OM1: 62.5/125 µm core, operates at 850 nm wavelength. Supports up to 300 meters.
• OM2: 50/125 µm core, 850 nm. Supports up to 500 meters.
• OM3: Laser-optimized, supports 10 Gbps over 300 meters.
• OM4: Improved attenuation, supports 10 Gbps over 550 meters.
• OM5: Wideband multimode fiber for 100 Gbps transmission across 850–950 nm wavelengths.

Singlemode Core Types (G.652.D, G.655, G.657.A1, G.657.A2):

Singlemode fiber cables have thinner cores and support long-distance, low-loss data transmission. They are widely used in outdoor backbones, Metro Ethernet, and FTTH projects.

• G.652.D: The most common SM fiber type, widely used in telecom networks.
• G.655: Non-Zero Dispersion Shifted Fiber, ideal for long-distance DWDM applications.
• G.657.A1: Fully compatible with G.652.D, offers better bend performance. Used in FTTH and indoor wiring.
• G.657.A2: Ultra-flexible, preferred in tight spaces like wall outlets and in-building terminations.

Core type directly affects fiber optic cable price. For example, G.657.A2 cables require higher precision manufacturing, thus are more expensive but provide superior performance in tight spaces.

3. CPR Classification

In EU-compliant construction projects, cables must meet CPR (Construction Product Regulation) standards. Classes like B2ca, Cca, and Dca define fire resistance levels. B2ca fiber optic cables provide the highest level of fire safety by minimizing smoke and toxic gas emissions during a fire.

4. Sheath Material

Sheathing materials vary, including PVC, PE, LSOH (LSZH), and PUR. LSOH jackets are preferred in areas with high human occupancy, while PE jackets are favored for outdoor applications due to their weather resistance.

5. Cable Armor

To enhance physical durability and protection from external factors, fiber optic cables often include armor layers. This is critical for environments with rodent threats, excavation activity, or demanding outdoor use.
Armor types include:

• Steel Wire Armor (SWA): Galvanized steel wires around the cable offer robust protection for outdoor installation.
• Steel Wire Braid (SWB): More flexible, ideal for confined spaces and moving environments.
• Corrugated Steel Tape: Spiral steel tape around the cable for both mechanical protection and rodent resistance.
• Galvanized Steel Tape: Flat steel tape for a more compact armor alternative.
• Non-Metallic Armor (Aramid Yarn): Common in ADSS (All-Dielectric Self Supporting) cables used near power lines, offering tensile strength without conductivity.

The choice of armor depends on environmental risks, installation method, and cable routing. For tunnels or direct burial, SWA or corrugated steel tape is preferred. For aerial installations, aramid-reinforced ADSS is ideal.

What is the Data Transmission Speed of Fiber Optic Cables?

Fiber optic cables offer significantly higher data transmission speeds compared to copper cables. Since transmission is achieved via light, they are unaffected by electromagnetic interference—an essential advantage in industrial environments. Singlemode (e.g., G.652.D) cables are suitable for data rates between 10 Gbps and 100 Gbps over long distances. Multimode cables like OM3 and OM4 can be used in data centers for 40 Gbps and 100 Gbps speeds over shorter distances. Distance also plays a key role. While singlemode cables support transmission across kilometers, multimode cables are optimized for shorter ranges. Additionally, data transmission speed depends not only on the fiber cable itself but also on the transceivers and equipment connected at both ends. Even the best cable can underperform if paired with low-quality devices. ETK Kablo is a leading fiber optic cable manufacturer.