Multimode armored optical cables can be spliced using either fusion or mechanical splicing, with careful preparation of the armored layers, fiber stripping, and protective heat-shrink or stainless steel tubing to ensure low-loss, durable connections.

Splicing Techniques

1. Fusion Splicing Fusion splicing is the preferred method for multimode fibers due to its low splice loss (typically <0.1 dB) and high reliability. The process involves aligning the fiber cores precisely and using an electric arc to fuse them together. Key steps include:

• Stripping the fiber coatings: Remove polyimide or acrylate coatings using a fiber stripper and clean with alcohol and lint-free wipes .
• Cleaving the fiber: Use a precision cleaver to create a flat, perpendicular endface.
• Aligning and fusing: Place the fibers in a fusion splicer, which automatically aligns the cores and applies an arc to join them .
• Protecting the splice: Slide heat-shrink tubing or stainless steel sleeves over the splice to protect it from mechanical stress and environmental factors . 2. Mechanical Splicing Mechanical splicing is an alternative when fusion splicing equipment is unavailable. It involves aligning the fiber ends in a precision sleeve with index-matching gel to minimize optical loss (typically ~0.2 dB). Steps include:
• Strip and clean the fiber ends.
• Insert fibers into the mechanical splice holder, ensuring proper core alignment.
• Secure the splice and apply protective tubing or enclosure .

Armored Cable Preparation

Splicing armored cables requires additional steps due to the metallic or Kevlar layers:

• Cut the cable to the desired length and slide protective heat-shrink tubing and stainless steel sleeves over the cable before splicing .
• Remove the outer armor carefully using appropriate cutters or abrasive wheels, exposing the inner fiber and Kevlar strands.
• Trim Kevlar fibers close to the jacket to prevent interference with the splice. Kevlar can be clamped or tied back to maintain tension relief .
• Ensure minimum cable diameter is maintained for proper handling and protection .

Post-Splice Considerations

• Testing: Measure insertion loss and back reflection to verify splice quality. Multimode fibers are sensitive to misalignment and core mismatch, which can increase attenuation .
• Enclosure: Place the spliced fiber in a splice tray or protective enclosure to prevent mechanical damage and maintain bend radius.
• Documentation: Record splice locations, loss values, and cable identifiers for future maintenance . By following these methods, multimode armored optical cables can be spliced efficiently while maintaining low optical loss and long-term reliability. Proper preparation, alignment, and protection are critical to ensure the performance of the fiber network.