Joining Fiber Cable – What Are the Options?

  Even with careful planning, fiber cables are seldom the perfect length and are notoriously difficult to join in the field. This often requires cutting or connecting cables on-site, introducing potential complications. This post explores the options available to installers—from splicing and field-fit connectors to pre-terminated solutions.

1. Splicing in the Field

Early fiber deployment relied on mechanical splicing, where fibers were aligned and housed in a mechanical sleeve. This method was soon replaced by fusion splicing due to its superior reliability and lower signal loss, which works by welding fiber ends together for a seamless connection. Despite offering the highest quality joint among field options, fusion splicing is time-intensive and demands specialized equipment and skilled operators. Success is never guaranteed, and accessing qualified engineers—often at high cost—poses a major constraint, especially in developing regions. Nevertheless, for large telecom operators with dedicated training and resources, fusion splicing remains a financially viable solution.

2. Field-Fit Connectors

In the 1980s, ceramic ferrule connectors were first developed by NTT in Japan and later advanced by other companies, enabling mechanical field attachment to fiber ends. While offering a cheaper alternative to splicing with lower skill and equipment requirements, these connectors introduce a third component that adds an extra point of signal loss—potentially pushing performance below acceptable limits. They are also vulnerable to failures from contaminants like water or dirt, as well as temperature fluctuations that may compromise long-term reliability. Despite these drawbacks, they remain a cost-effective solution for many field applications.

3.Pre-Connectorized or Factory-Terminated

Factory-terminated fiber cables are manufactured under expert supervision in controlled, clean environments free from field contaminants. Each assembly undergoes thorough testing with documented results provided for quality assurance. Available in various performance grades, these pre-connectorized solutions reduce on-site labor, material costs, and installation time while improving performance. Ultimately, they enhance network reliability through manufacturer-guaranteed quality.

4. Pre-Connectorization and Field-Fit/Splicing

Factory-terminated cables offer reduced labor costs, higher performance, and faster deployment, but require precise planning of panel locations and cable lengths. A key drawback is the excess cable often left over, which must be coiled and stored on-site—an often unsightly solution. As an alternative, some operators adopt a hybrid approach: one end pre-terminated and the other field-fitted or spliced. This reduces fiber waste and avoids storage boxes, though it still demands semi-skilled labor and comes with higher connector costs and signal loss.