An optical-fiber ribbon includes intermittent gaps along its longitudinal length in which no bonding material is present across the width of the optical-fiber ribbon. These intermittent gaps without bonding material (e.g., adhesive beads) help to reduce or eliminate bonding-material interference as the optical-fiber ribbon is positioned within an alignment chuck during preparations for mass-fusion splicing.

This intermittent connection-type optical fiber tape core is configured in a manner such that in a state where a plurality of optical fiber cores are arranged in parallel in a direction perpendicular to the lengthwise direction of said plurality of optical fiber cores, some or all of the intervals between the plurality of optical fiber cores are intermittently provided in the lengthwise direction with connected sections where the intervals between adjacent optical fiber cores are connected and non-connected sections where the intervals between adjacent optical fiber cores are not connected. The outer diameter of each of the plurality of optical fiber cores is 160-220 μm, inclusive. The catenary amount of the tip end of the intermittent connection-type optical fiber tape core projecting from the held location is 0.1-2 mm, inclusive, in a given state.

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 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.

An optical fiber unit according to the present disclosure includes a plurality of intermittently-connected optical fiber ribbons. At least one of the optical fiber ribbons includes a plurality of optical fibers including a first optical fiber, and a second optical fiber that is longer than the first optical fiber. Conditions (AA) and c<0.05 are satisfied, where b is an interval, in a length direction, between connection parts that connect the first optical fiber and the second optical fiber, c (%) is a fiber length difference of the second optical fiber with respect to the first optical fiber, and Y is an interval between the optical fibers in a ribbon width direction. (AA):

[00001]$C>100\times \left\{\sqrt{{\left(\frac{2Y}{b}\right)}^2+1}-1\right\}$

The present disclosure relates to an optical fiber ribbon in which the optical fibers of the optical fiber ribbon are intermittently bonded together at bonding regions along the length of the optical fiber ribbon. The bonding regions of the optical fiber ribbon each include a joining ribbon matrix that have different colors along the length of the optical fiber ribbon.

An optical cable includes optical fiber units each of which includes intermittently-coupled optical fiber ribbons. In at least one of the optical fiber units, in a cross section perpendicular to a longitudinal direction of the at least one of the optical fiber units, a length of a vector GU is shorter than a largest length of vectors MG of the intermittently-coupled optical fiber ribbons forming the at least one of the optical fiber units, where, in each of the intermittently-coupled optical fiber ribbons, each of the vectors MG is a vector starting from M and ending at G, M is a midpoint between optical fibers at both ends of the each of the intermittently-coupled optical fiber ribbons, and G is a center of gravity of the each of the intermittently-coupled optical fiber ribbons, and the vector GU is a resultant vector of the vectors MG.

An optical fiber cable includes optical fiber ribbons and a sheath covering a periphery of the plurality of optical fiber ribbons. Each of the optical fiber ribbon includes optical fibers, and a connected portion and a non-connected portion are intermittently provided in the longitudinal direction. Each optical fiber includes a glass fiber and a coating portion. A ratio of an inner diameter to an outer diameter of the sheath is 0.75 or more. A ratio of a total area of glasses in an optical fiber ribbon accommodating portion to an area of the optical fiber ribbon accommodating portion is 15% or more and 25% or less, the number of the optical fibers in the optical fiber cable is 3000 or more, and the outer diameter of the sheath is 50 mm or less.

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.

A connection system includes an optical connector assembly; and an optical plug. The connector assembly includes a stack of gel-groove assemblies and a spring assembly mounted within a housing. Each of the gel-groove assemblies includes a first gel block at a first axial end, a second gel block at a second axial end, and a fiber mating region between the first and second gel blocks. The optical plug including sub-modules over-molded over arrays (e.g., ribbons) of the optical fibers. Each sub-module defines notches for receiving latches of the spring assembly when the optical plug is coupled to the first axial end of the optical adapter. Bare optical fibers extend from the plug, pass through the first axial gel block, and enter the fiber mating region when the plug is coupled to the adapter.