There is a step in the optical cable fusion splice joint

A fusion splice joint is created by precisely preparing, aligning, fusing, protecting, and testing two optical fibers to form a permanent, low-loss connection.Step 1: Fiber Preparation

Begin by stripping the outer jacket and buffer coating of the fiber to expose the bare glass, typically using a 250µm stripper for single fibers and a separate tool for the outer jacket. Clean the exposed fiber with 99% isopropyl alcohol to remove oils and debris, as contamination can weaken the splice or increase loss. Handle fibers carefully to avoid bending below a 30 mm radius or introducing tension, which can cause microfractures or breakage during splicing .

Step 2: Cleaving

Use a precision cleaver to cut the fiber ends at a near-perfect 90-degree angle. A clean, flat, mirror-like cleave is critical because any chips or angled ends can result in high splice loss or failure. Inspect the cleave under a microscope to ensure quality before proceeding .

Step 3: Fiber Alignment

Place the cleaved fibers into the fusion splicer's V-grooves or clamps. Modern splicers use optical core alignment or profile alignment to automatically align the fiber cores. Some ribbon splicers use multiple fibers at once, while single-fiber splicers handle one fiber at a time. Proper alignment ensures minimal signal loss and reflection .

Step 4: Fusion

Activate the splicer to generate an electric arc that melts the fiber ends together. The fusion process forms a continuous glass path between the fibers, creating a permanent, ultra-low-loss joint. The splicer software often estimates splice loss immediately after fusion .

Step 5: Splice Protection

After fusion, slide a heat-shrink splice protection sleeve over the joint and use the splicer's heating element to shrink it. This protects the splice from mechanical stress, moisture, and environmental damage, ensuring long-term reliability .

Step 6: Testing

Finally, verify the splice quality using an OTDR (Optical Time-Domain Reflectometer) or a loss test set. Testing confirms that the splice meets the required optical loss and tensile strength standards, ensuring the joint will perform reliably in the network . By carefully following these steps—preparation, cleaving, alignment, fusion, protection, and testing—you can achieve a high-quality, durable fusion splice joint with minimal signal loss.