What Is a Fiber Pigtail?

A fiber pigtail is one of the two main ways of connecting large multi-strand cables with other cables and equipment. The end-form of these cables is typically made up of a single fat cable that is filled with smaller cores. When the large cable ends, the pigtail separates all the inner cables into their own own strands and caps them with some form of terminal connector. These cables are often optical or coaxial systems and are used heavily in audio/video systems and computer networking.

The most common place to find a fiber pigtail is on the end of a main connection cable that runs to a large area from outside. This might be a single cable that runs into a production studio or a bundle of coaxial cable that terminates at a specific floor in an apartment building. In either case, the idea is the same; a lot of cables are bound together for ease of movement but need to be separated in order for people to use them.

The pigtail, when separate from a line, looks like a bundle of loose, capped wires that are bound together on one end. The bound end connects to the main cable, where the individual strands of the fiber pigtail are permanently fused, or spliced, to the multicore cable. When the process is complete, the fiber pigtail is a non-removable piece of the system.

The non-bound ends of the fiber pigtail contain some type of connector. These connectors vary based on what the pigtail is connected too. For instance, a pigtail off a cable line would have coaxial connectors, but a communication system may have network or telephone ends. Some types of pigtails have several different types of connectors all coming from the same main cable.

The other main type of connector is a breakout cable. These look very similar to a pigtail, but they don’t have terminals. These types of connectors break up the main cable into smaller pieces without capping while giving the cables protection from physical damage. This allows individual lines to connect to cables that continue on while others can have individual terminals placed on them as needed. These ends are also usually permanent once attached.

These two cables were originally the cornerstone of the telecommunications system. Main telephone systems would use breakout cables to slowly divide lines down into local neighborhoods. At the end of the system, a pigtail would create the final split between the outside systems and home wires. While the essence of these hierarchical systems may still be found, satellite and broadcast technology has greatly reduced the amount of cables used.