New type of butterfly-shaped fiber optic cable for safe city

Butterfly-shaped fiber optic cables offer enhanced safety, flexibility, and durability for urban telecommunications and smart city infrastructure.Design and Structure

Butterfly-shaped fiber optic cables feature a flat, wing-like profile with optical fibers running along the center, flanked by two parallel strength members. This unique geometry allows the cable to bend easily in the flat plane while resisting sharp kinks edge-on, providing a built-in safeguard against accidental damage during installation . The strength members are typically Fiber Reinforced Plastic (FRP) or sometimes steel wire for outdoor self-supporting runs, ensuring tensile strength without introducing electrical hazards . The outer sheath is often LSZH (Low Smoke Zero Halogen) or LSOH, making it flame-retardant and safe for indoor urban environments .

Advantages for Safe City Applications

1. Enhanced Safety: Non-metallic FRP members eliminate lightning risks and electromagnetic interference, while LSZH sheaths reduce toxic smoke in case of fire .
2. Flexibility and Compactness: The flat design allows routing through tight spaces, walls, and conduits in dense urban areas without stressing the fiber core .
3. Durability: Outdoor variants with steel wire reinforcement can span up to 50 meters without external support, making them suitable for aerial installations .
4. Bend-Insensitive Fiber: Most butterfly cables use ITU-T G.657 single-mode fibers, tolerating tight bend radii and ensuring minimal signal loss in complex city layouts .

Installation and Connectivity

Butterfly cables can be connected using fusion splicing, which provides low-loss permanent connections, or mechanical splicing for temporary setups . Their directional design simplifies installation along walls, ceilings, and conduits, reducing the risk of accidental fiber breakage during urban construction or maintenance .

Applications in Urban Environments

• FTTH (Fiber to the Home) deployments in apartments and office buildings .
• Indoor distribution networks in hospitals, schools, and commercial complexes where fire safety and low-toxicity materials are critical .
• Aerial self-supporting runs for connecting utility poles to buildings without additional support structures .
• Smart city infrastructure, including IoT networks, traffic management systems, and public safety communications, benefiting from the cable's compact, safe, and flexible design .

Conclusion

Butterfly-shaped fiber optic cables combine safety, flexibility, and high optical performance, making them ideal for modern urban deployments. Their flat, reinforced design, bend-insensitive fibers, and fire-safe sheaths ensure reliable connectivity while minimizing hazards, supporting the development of safe, resilient city networks .