Elimination Of Manual Cleaving And De-Nubbing In The Polishing Of Connectorized Fiber End-Faces

The prospect of automating the fiber connectorization process has always proven to be a difficult endeavor. The primary complexity relates to the inherent variations in the initial end-face condition of the connectorized fiber. Specifically, variations in epoxy bead size and fiber protrusion precludes one from setting fixed machine polishing positions and pressures for uniform material removal.

Typically, a fiber is stripped to be more than ten millimeters longer than the connector ferrule length; bonded to the connector with epoxy; and then cleaved manually to be about 50 to 500 microns above the epoxy bead.

The protruding fiber is then manually de-nubbed using a coarse polishing film. In order to compensate for operator error, epoxy beads tend to be fairly large and fibers are cleaved longer than necessary. The added epoxy size and exposed fiber naturally require excessive manual de-nubbing and polish time, adding labor and consumables cost, without adding value to the end product.

Automated fiber cleaving techniques range from simple mechanical devices to high powered, laser based instruments designed to cut the fiber as close to the ferrule surface as possible. Mechanical cleaving inherently leaves a cleave wedge along with providing very poor length and angle control. Laser based cleavers on the other hand, are expensive and display fiber geometry variations, such as length (typically +/-10 microns), flatness, and surface finish which are significant enough to require additional polishing on separate equipment in order to comply with industry accepted criteria for end-face geometry.