A melting coil is necessary only for fusion splicing; cold splicing does not require melting.

Fusion Splicing

Fusion splicing joins two optical fibers by melting their ends together using an electric arc or heating element, creating a seamless joint with minimal signal loss, typically around 0.02–0.05 dB . The process involves stripping the fiber coating, cleaning the bare fiber, aligning the cores precisely, and then applying heat to fuse the fibers. After fusion, a protective sleeve is applied and heated to reinforce the joint . Fusion splicing is preferred for long-distance, high-speed, or permanent installations due to its low insertion loss and durability .

Cold Splicing

Cold splicing, on the other hand, does not use heat or melting. Instead, fibers are aligned in a precise V-groove or mechanical connector, often with an index-matching gel to reduce signal loss . This method is faster, requires less equipment, and is suitable for field repairs, temporary setups, or FTTH (fiber-to-the-home) applications. The typical splice loss is higher than fusion splicing, around 0.2–0.5 dB, and the connection is less durable under environmental stress .

Conclusion

Whether a melting coil is necessary depends on the splicing method:

• Fusion splicing: Yes, melting is essential to create a low-loss, permanent joint .
• Cold splicing: No, fibers are joined mechanically without heat, suitable for quick or temporary connections . Choosing between the two depends on project requirements, budget, and desired splice quality. Fusion splicing is ideal for high-performance networks, while cold splicing is practical for fieldwork or cost-sensitive applications.