Alcatel

Draka Comteq B.v.

Christopher L Johnson

Nicholas V Nechitailo

Stefan Richter

Pierre Gaillard

Geoffrey Witt

Matthew Barber

The present invention introduces a concept of 'smart' ribbons, which use functionally tensioned optical fibers during the manufacture of fiber optic ribbons to create fiber ribbons with controlled geometrical configuration, optimized strain distribution and reduced attenuation. The ribbons may have flat or bowed cross section and be straight along the length or curved in its plane, or twisted unidirectionally, or periodically. These shapes and residual stress-strain state are induced and controlled by using tension functions instead of traditional constant-value tension per fiber during the ribbon manufacture. Further, the present invention reduces signal loss and/or attenuation in ribbon fibers caused by an increase in the strain variation from tensile strain to compressive strain along the length of the individual fibers when ribbons are manufactured, stacked, stranded around a strength member or twisted and bent during cable installation. In a first embodiment of the present invention, either a symmetric or non-symmetric load distribution is applied across the fibers being placed or drawn into a ribbon structure to eliminate or control residual twist in a completed fiber ribbon. Additionally, in the present invention, the load distribution on the fibers of a ribbon can be varied (e.g. periodically changed) along the length of the ribbon to provide a ribbon with the required design characteristics for any particular application. In a second embodiment of the invention, a fiber optic ribbon is made up of a plurality of sub-unit ribbons arranged in substantially the same plane. Each sub-unit ribbon includes a plurality of optical fibers coated by sub-unit matrices.

Functionally strained optical fibers

The invention is a cable assembly in which the ripcord is bonded or woven to the cable assembly's armor tape. This arrangement helps to prevent the ripcords from moving from their initial position, therefore allowing better dissection of a cable sheath and/or jacket. The cable assembly includes a cable core (e.g., soft buffer tubes surrounding optical fibers), a tape surrounding the cable core, at least one ripcord attached to the tape, and a cable jacket surrounding the tape. In a second embodiment of the present invention, a cable assembly includes a cable core having a predetermined axial length, a cable jacket for housing the cable core along the predetermined axial length of the cable core, and a ripcord disposed between the cable core and the cable jacket along the predetermined axial length, in a manner that the ripcord is contained within the predetermined axial length, but the ripcord has a length substantially longer that the predetermined axial length. In a preferred embodiment of the present invention, the ripcord is disposed along the predetermined axial length in a wavy shape, thus the ripcord is made &ldquo;flexible&rdquo;, alleviating damage to the cable assembly that can occur from ripcord tension.

Cable assembly having ripcords with excess length and ripcords attached to tape

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Granite Falls, NC, United States of America

Christopher L Johnson