An optical fiber cable includes: a sheath; a core that is housed in the sheath and comprises optical fibers; tensile strength members embedded in the sheath; and ripcords embedded in the sheath. Recesses and protrusions are disposed alternately in a circumferential direction on an outer circumferential surface of the sheath. The recesses each include: two connecting portions respectively connected to radial inner ends of two adjacent protrusions; and a bottom surface positioned between the two connecting portions. In a transverse cross-sectional view, the ripcords are positioned inside some of the protrusions, and the tensile strength members are positioned inside the remaining protrusions.

The present invention relates to an optical fiber cable (100, 200, 300) comprising a plurality of tubes (104) and a sheath (114) encapsulating the plurality of tubes (104) with a plurality of optical fibers (106). At least one tube of the plurality of tubes (104) has young's modulus that is different from other tubes and the young's modulus that is at least 30% more than young's modulus of the other tubes. In particular, the plurality of tubes (104) is arranged in an innermost layer (108) and an outermost layer (110). Additionally, young's modulus of the innermost layer (108) is greater than young's modulus of the outermost layer (110). Further, the diameter of the central strength member (102) is in a range of 1.5 millimetres to 6 millimetres.

A machining method for an optical fiber unit, includes: preparing an optical fiber unit in which a first optical fiber ribbon that intermittently connects a first plurality of optical fibers and a second optical fiber ribbon that intermittently connects a second plurality of optical fibers are layered and arranged, the first optical fiber ribbon and the second optical fiber ribbon are intermittently connected in a length direction by interlayer connection parts; opening up a separation part between the first optical fiber ribbon and the second optical fiber ribbon; and breaking the interlayer connection parts by inserting a finger or a division tool into the opened separation part.

An optical fiber ribbon includes a plurality of optical fiber cores arranged in parallel in a direction orthogonal to a longitudinal direction of the optical fiber cores, and a coupling member configured to couple the plurality of optical fiber cores. In the optical fiber ribbon, a plurality of coupled sections and a plurality of separate sections are alternately provided in the longitudinal direction. Each of the plurality of coupled sections is in a state in which all of the adjacent optical fiber cores are coupled by the coupling member. Each of the plurality of separate sections is in a state in which at least two of the optical fiber cores adjacent to each other are not coupled by the coupling member.

A rollable optical fiber ribbon utilizing low attenuation, bend insensitive fibers and cables incorporating such rollable ribbons are provided. The optical fibers are supported by a ribbon body, and the ribbon body is formed from a flexible material such that the optical fibers are reversibly movable from an unrolled position to a rolled position. The optical fibers have a large mode filed diameter, such as ≥9 microns at 1310 nm facilitating low attenuation splicing/connectorization. The optical fibers are also highly bend insensitive, such as having a macrobend loss of ≤0.5 dB/turn at 1550 nm for a mandrel diameter of 15 mm.

An optical fiber unit includes: a first optical fiber ribbon that intermittently connects a first plurality of optical fibers; a second optical fiber ribbon that intermittently connects a second plurality of optical fibers; and interlayer connection parts that intermittently connect the first optical fiber ribbon and the second optical fiber ribbon in a length direction while the first optical fiber ribbon and the second optical fiber ribbon are layered and arranged. The first optical fiber ribbon and the second optical fiber ribbon are layered and arranged such that optical fibers having a same fiber number of the first optical fiber ribbon and the second optical fiber ribbon are aligned in a up-down direction perpendicular to the length direction.

An optical fiber cable includes a slot rod that is provided with a plurality of slot grooves in a spiral shape stranded in one direction, a tensile strength member that is provided inside the slot rod to receive tension, a cable sheath that covers an outer side of the slot rod, and a plurality of optical units made by gathering optical fiber ribbons in which a plurality of optical fibers is arranged in parallel. In each of the optical units, the optical fiber ribbons are stranded with each other along a longitudinal direction of the optical fiber cable. Each of the optical units is accommodated in corresponding one of the slot grooves along the longitudinal direction in a state where relative positional relationships between the optical units and the slot grooves are kept and relative positional relationships between the optical units are kept.

An optical fiber cable that includes subunits is provided. Optical fiber cables are used to transmit data over distance. Generally, large distribution cables that carry a multitude of optical fibers from a hub are sub-divided at network nodes into subunits. To furcate the subunits, the respective jackets of the subunits must balance many different characteristics, including flexibility, temperature tolerance, and safety properties.

An optical cable is provided. The optical cable includes an outer cable body jacket and a plurality of optical fiber subunits. The optical fibers within each subunit are stranded relative to each other and are located within a thin subunit jacket. A plurality of unstranded optical fiber subunits are located within the cable jacket.

[Problem] When a surface of the optical fiber ribbon is rough, the microbending loss is increased due to the irregularities formed on the surface of the optical fiber ribbon.

[Solution] An intermittently connected optical fiber ribbon of the present disclosure, includes: a plurality of optical fibers arranged in a predetermined direction; and connecting portions that intermittently connect two adjacent ones of the optical fibers. A peripheral cover portion formed of resin configuring the connecting portions is formed on a periphery of the optical fibers. An arithmetic mean roughness Ra of a surface of the peripheral cover portion is 0.41 μm or lower.