Self-supporting butterfly optical cable

A self-supporting butterfly optical cable is a fiber optic cable designed with a butterfly-shaped cross-section that can carry its own weight outdoors while also being suitable for indoor deployment.

Structure and Design

A self-supporting butterfly optical cable features a central optical fiber unit surrounded by a bow- or butterfly-shaped sheath. Two parallel Fiber Reinforced Plastics (FRP) or similar reinforcements are placed on either side of the fiber core, and sometimes a steel wire is added for additional tensile strength . The outer sheath is typically made of low-smoke, halogen-free (LSZH) or flame-retardant PVC material, providing protection against environmental factors . Cable separation yarns are often included between the external protective layer and the optical core to facilitate stripping and splicing . The butterfly shape allows the cable to maintain dimensional stability and resist bending or crushing, while the self-supporting design enables it to be suspended between poles or along walls without requiring a separate messenger wire .

Key Features

• Self-supporting: Can carry its own weight in aerial installations, eliminating the need for additional support wires .
• Indoor/outdoor versatility: Can be used outdoors as an overhead cable and indoors for direct building entry after removing suspension components .
• Bend-insensitive fiber: Often uses ITU-T G.657 standard fibers, allowing tight bends without signal loss, suitable for dense urban or multi-tenant buildings .
• Mechanical protection: Parallel FRP members and optional steel wires provide crush resistance and tensile strength, protecting the fiber from breakage .
• Ease of installation: The butterfly design and flute structure simplify stripping, splicing, and connection to quick-connect or cold fiber joints .

Applications

Self-supporting butterfly optical cables are widely used in FTTH, FTTB, and FTTO networks, as well as in campus networks, intelligent buildings, and local area networks . They are ideal for aerial distribution from poles to buildings, vertical risers, and direct building entry, providing a reliable and cost-effective solution for both residential and commercial fiber deployments.

Advantages

• Reduces installation complexity by combining indoor and outdoor use in a single cable.
• Improves reliability and stability of optical transmission due to reinforced structure.
• Supports long-distance and local area network communication with high bandwidth and low signal loss.
• Simplifies maintenance and splicing operations due to its structured design and separation yarns. In summary, a self-supporting butterfly optical cable is a versatile, mechanically robust fiber optic solution designed for both aerial and indoor deployment, offering ease of installation, high reliability, and suitability for modern fiber access networks .