Fiber optic connector connection failure analysis

Why do fiber optic connectors fail? There are several diagnostic methods to help troubleshoot fiber optic connectors, and the diagnostic method is to cross-section the fiber optic connector. This technology allows us to actually look inside the fiber optic connector to see defects and pinpoint the cause of failure.

Fiber optic connectors are first vacuum impregnated with metallographic grade epoxy. It is then cut at various locations and terminated at the approximate longitudinal midpoint of the fiber in the ferrule.

Cross-sectioning allows us to zero in on specific areas of fiber optic connector assemblies to identify potential defects. While analyzing this cross-section fiber optic connector, I found several localized fiber breaks in critical areas as well as one complete fiber break.

Fiber optic connector failure

In these zoomed-in images of this fiber optic connector, note a section of the fiber that is broken at a critical location.

The optical fiber connector

Other enlarged images of the same fiber optic connector. Note the local breakage of the fiber within the confines of the fiber bonding epoxy.

In the same fiber optic connector, the gap between the epoxy-bonded fiber and the internal fiber optic connector surface shows that the epoxy-bonded fiber exhibits significant shrinkage. In the image above, notice the significant shrinkage of the fiber bonding epoxy at the red arrows.

Cross-sectioning is an effective diagnostic tool, a practical solution to identifying process problems that can be resolved.

As you can see from the photo above, cross-sectioning provides the unique ability to identify and isolate problems associated with fiber optic terminations that would otherwise be invisible. A cross-section service in the center of the fiber can reveal breaks, nicks, microbends, shrinkage and microcracks in the fiber. Insufficient/too much epoxy or air bubbles in the epoxy; and problems with wire stripping, crimping, etc.

When a fiber optic connector fails, a cross section can help determine the cause and identify process issues. Fiber Center customers rely on this diagnostic service to visually analyze their fiber optic connectors, identify defects, diagnose potential causes and implement process improvements.

This enables you to perform regular audits and rapid failure analysis when you implement internal cross-cutting capabilities.