What are the structural features of butterfly-shaped optical cables

A butterfly-shaped optical cable features a flat profile with optical fibers centered between two parallel strength members, encased in an LSZH or PVC sheath for flexibility, durability, and ease of installation.

Core Structure

Optical Fibers: The fibers are positioned at the center of the cable, often using single-mode fibers like G.657A1 or G.657A2, which provide high bend resistance and low signal loss in tight indoor routing . Strength Members: Two parallel Fiber Reinforced Plastic (FRP) or steel wires run along the sides of the fibers. These members provide tensile strength, compressive protection, and help maintain the flat, butterfly-shaped geometry . Sheath: The outer layer is typically made of Low Smoke Zero Halogen (LSZH) or PVC, offering flame retardancy, environmental safety, and mechanical protection. For outdoor applications, UV-resistant PE sheaths may be used . Flat, Butterfly Shape: The flat design reduces bending stress, prevents rolling, and simplifies routing along walls, corners, and conduits. This geometry also allows for compact installation in FTTH (Fiber to the Home) networks and last-mile deployments .

Additional Design Features

• Tearing Grooves and Grooves for Fiber Access: Some designs include grooves or tearing openings to facilitate easy separation and connection of fibers during installation and maintenance .
• Reinforcement Integration: In advanced designs, the butterfly-shaped units may include semi-cylindrical or cuboid protective bodies that house the fibers and reinforcing members, forming a stable polyhedral structure for enhanced durability .
• Compact and Flexible: The structure minimizes outer diameter, reduces material cost, and allows flexible deployment in indoor and outdoor environments .

Practical Advantages

• Ease of Installation: Flat geometry prevents twisting and rolling, reducing labor and installation time .
• Mechanical Reliability: Strength members protect fibers from tensile and compressive forces, while the sheath ensures environmental protection .
• Space Efficiency: The compact design is ideal for building entry solutions and dense FTTH networks .
• Versatility: Suitable for indoor cabling, drop cable systems, and last-mile fiber access . In summary, the butterfly-shaped optical cable combines centered optical fibers, parallel strength members, and a protective sheath in a flat, compact design that enhances mechanical performance, installation efficiency, and space utilization, making it ideal for modern FTTH and access network deployments .