An optical fiber cable including an optical fiber ribbon in a pipe, wherein the ribbon includes at least two optical fibers arranged side by side, and wherein at least two of the optical fibers are bonded intermittently along a length of the fibers.

This application relates to fibre optic cables structures which are particularly suited for use for distributed fibre optic sensing. A fibre optic cable structure (300, 500) is described which includes a cable core (301, 501) and a longitudinal strength member (302, 502). The cable core has at least one optical fibre (301a, 501a) and, optionally, one or more surrounding layers (505) and/or a strain transformer. (504) The cable core and is fixedly coupled to the longitudinal strength member at periodic fixed coupling points (303, 503). At the fixed coupling points the cable core has a substantially fixed position with respect to the longitudinal strength member and between the fixed coupling points the cable core is free to move with respect to the strength member. For an operating range of tensile load and pressure, the length (Lcoup) of the cable core between any two adjacent fixed coupling points is greater than the axial distance (Dcoup) along the fibre optic cable structure between the fixed anchoring points.

An optical fiber cable is provided. The cable includes: an optical fiber core having a central axis; a presser winding covering the optical fiber core; a sheath covering the presser winding; two tension members in the sheath and facing each other with the central axis therebetween; and two rip cords facing each other with the central axis therebetween and being in direct contact with the sheath and the presser winding. The optical fiber core includes a plurality of optical fiber tapes arranged around the central axis and having mutually different stripe ring marks applied thereon. Each optical fiber tapes includes a plurality of optical fibers intermittently adhered to each other.

Embodiments of the present invention address aliasing problems by providing a plurality of discrete acoustic sensors along a cable whereby acoustic signals may be measured in situations where the fibre optic cable has not been secured to a structure or area by a series of clamps. Acoustic sampling points are achieved by selectively enhancing the acoustic coupling between the outer layer and the at least one optical fibre arrangement, such that acoustic energy may be transmitted selectively from the outer layer to the at least one optical fibre arrangement. The resulting regions of acoustic coupling along the cable allow the optical fibre to detect acoustic signals. Regions between the outer layer and the at least one optical fibre arrangement that contain material which is acoustically insulating further this enhancement since acoustic waves are unable to travel through such mediums, or at least travel through such mediums at a reduced rate.

A flexible optical ribbon and associated systems and methods of manufacturing are provided. The ribbon includes a plurality of optical transmission elements and an inner layer comprising a cross-linked polymer material and an outer surface. The outer surface of the inner layer includes first areas having first concentrations of uncrosslinked polymer material and second areas having second concentrations of uncrosslinked polymer material. The first concentrations are greater than the second concentrations. The ribbon includes an outer polymer layer having an inner surface interfacing with the outer surface of the inner layer. The outer polymer layer has a higher level of bonding to the inner layer at the first areas than at the second areas due to the ability of the outer polymer material to bond or crosslink with the larger numbers of uncrosslinked polymer material in the first areas.

Embodiments of the invention include a method for making a partially bonded optical fiber ribbon. The method includes providing a linear array of optical fibers, and applying with an ink jet printing machine a bonding matrix material to at least a portion of at least two adjacent optical fibers. The applied bonding matrix material has a viscosity of approximately 2.0 to approximately 10.0 centipoise (cP) measured at 25 degrees Celsius ( C.). The applied bonding matrix material also has a conductivity of approximately 600 to approximately 1200 millimhos (mmhos). The applied bonding matrix material also has an adhesion of approximately 0.01 to approximately 0.20 Newtons (N). Also, the bonding matrix material is applied to at least a portion of at least two adjacent optical fibers in such a way that the linear array of optical fibers forms a partially bonded optical fiber ribbon.

An optical fiber cable is provided. The cable includes: an optical fiber core having a central axis; a presser winding covering the optical fiber core; a sheath covering the presser winding; two tension members in the sheath and facing each other with the central axis therebetween; and two rip cords facing each other with the central axis therebetween and being in direct contact with the sheath and the presser winding. The optical fiber core includes a plurality of optical fiber tapes arranged around the central axis and having mutually different stripe ring marks applied thereon. Each optical fiber tapes includes a plurality of optical fibers intermittently adhered to each other.

A fiber optic distribution cable includes a central inner jacket formed from one of a polyvinyl chloride or a low smoke zero halogen material, a plurality of optical fibers disposed within the inner jacket, and a plurality of first strength members disposed within the inner jacket. The fiber optic distribution cable further includes an outer jacket surrounding the central inner jacket, the outer jacket formed from the one of the polyvinyl chloride or the low smoke zero halogen material, and a plurality of second strength members disposed between the outer jacket and the central inner jacket. A fiber density of the cable is greater than 0.65 fibers per square millimeter.

An optical fiber cable including an optical fiber ribbon in a pipe, wherein the ribbon includes at least two optical fibers arranged side by side, and wherein at least two of the optical fibers are bonded intermittently along a length of the fibers.

A fiber-bundle sub-assembly includes an array of fiber bundles each having at least one optical fiber. The fiber bundles have select relative positions in the array. The sub-assembly includes first and second connecting elements that run along the array and that are secured to axially staggered top and bottom anchors to define first and second connecting spans that cross first and second sides of the array, with the first and second sides defined by first and second sets of fiber bundles. The first and second connecting spans are respectively attached to the first and second sets of fibers bundles to maintain the select relative positions of the fiber bundles even when the connecting spans are cut near one of the anchors during processing. A loose-tube cable that includes the fiber-bundle sub-assembly and a method of connectorizing the fiber bundles while maintaining their select positions are also disclosed.