Optical cables can be divided into duct optical cables

Duct optical cables typically include single-mode or multimode fibers housed in loose tubes or ribbon formats, reinforced with strength members, and protected by various jackets and optional armor.

Core Components of Duct Optical Cables

Optical Fibers: Duct cables can contain single-mode fibers (e.g., G.652D, G.657A1) for long-distance telecom and backbone networks, or multimode fibers (e.g., OM3, OM4) for shorter, high-bandwidth applications like data centers and campus networks . Buffer Tubes: Fibers are organized in loose tubes, which may be gel-filled or dry water-blocking, to prevent moisture ingress and reduce microbends during installation . Strength Members: To withstand pulling and tension during installation, duct cables include aramid yarn (Kevlar), steel wires, or fiberglass rods as central or peripheral strength members . Outer Jacket: The cable jacket is made from materials such as PE (polyethylene), PVC, or LSZH (Low Smoke Zero Halogen), chosen for environmental resistance, flame retardancy, and UV protection . Armor (Optional): In high-risk areas, duct cables may include steel tape (GYTS) or aluminum tape (GYTA) for extra protection against rodents, construction damage, or crushing forces .

Cable Designs

Loose Tube Cables: Fibers are placed in individual tubes, often stranded around a central strength member. These can be single loose tube (up to 12 fibers) or multi-tube (up to 144 fibers) for backbone routes . Ribbon Cables: High-density cables with fibers arranged in flat ribbons, allowing mass-fusion splicing and higher fiber counts in a compact design, suitable for urban or long-haul networks . Micro and Mini Cables: Smaller-diameter cables designed for air-blown installation in microducts, offering high fiber counts while reducing duct congestion .

Common Duct Cable Models

• GJYXFHA/GJYXFHS: Light-armored, aluminum or steel tape, LSZH sheath, suitable for FTTH and duct installations .
• GYXY: Non-armored, central tube with steel wires, PE sheath, for aerial or duct use .
• GYFXY: FRP rods, uni-tube, PE sheath, lightweight for aerial/duct applications .
• GYXTW: PSP-armored central tube with steel wires, PE sheath, for duct installations .
• GYFA/GYFS/GYFTA: Armored, stranded loose-tube cables with PE sheath, designed for duct or direct burial under extreme conditions .

Summary

Duct optical cables are engineered for installation in pre-laid ducts, providing mechanical protection, moisture resistance, and flexibility. They include single-mode or multimode fibers, organized in loose tubes or ribbons, reinforced with strength members, and protected by jackets and optional armor. Variants like micro, mini, and armored cables allow adaptation to different network densities, installation methods, and environmental conditions .