Cables having buffer elements formed with two-dimensional fillers are described. A cable may include at least one optical fiber, and a buffer element may be formed around the at least one optical fiber. The buffer element may be formed from a material that includes a polypropylene-containing polymeric resin, a filler added to the polymeric resin that includes a plurality of two-dimensional particles, and an amphiphilic compatabilizer. A jacket may be formed around the at least one optical fiber and the buffer element.

A multicore fiber optic cable comprising of a central fiber having a central fiber outer diameter, a central fiber coating surrounding the central fiber outer diameter of the central fiber, the central fiber coating having a continuous spiraled groove around the central fiber outer diameter, a dual core optical fiber having a dual core optical fiber geometry, the dual core optical fiber spiraled around the central fiber coating and disposed within the spiraled groove such that the dual core optical fiber is wound around the central fiber coating in a spiral pattern and the central fiber core geometry and the dual core optical fiber geometry are oriented longitudinally to negate link path length difference; and an outer sheath surrounding the central fiber coating and the dual core optical fiber.

An MCF having a structure excellent in mass productivity and suppressing increases in splicing cost and loss are provided. The MCF includes 12 or 16 cores, a cladding, and a coating. The cores are arranged at positions of line symmetry while no adjacent relationship is established between the cores having an adjacent relationship with any core. A coating diameter is 235-265 .Math.m, a cladding diameter CD is from CD.sub.nominal -1 .Math.m to CD.sub.nominal +1 .Math.m with a nominal value CD.sub.nominal of 195 .Math.m or less, an MFD at 1310 nm is from MFD-reference-value -0.4 .Math.m to the MCF-reference-value+0.4 .Math.m with the MFD-reference-value of 8.2-9.2 .Math.m, and a 22m-cable-cutoff wavelength λ.sub.cc is 1260-1360 nm. A core’s zero-dispersion wavelength is a wavelength-reference-value - 12 nm to the wavelength-reference-value+12 nm with the wavelength-reference-value of 1312-1340 nm, and a dispersion slope at the wavelength is 0.092 ps/(nm.sup.2.Math.km) or less. A shortest distance from a cover-cladding interface to each core center, a structure, and optical characteristics satisfy predetermined conditions.

An optical fiber unit includes a plurality of optical fibers, a fibrous filler disposed along the plurality of optical fibers, and a resin film covering the plurality of optical fibers and the fibrous filler from outside. In the optical fiber unit, the resin film has a film thickness smaller than a diameter of the fibrous filler.

This MCF ensures sufficient manufacturing tolerance, is excellent in mass productivity, and is also capable of suppressing degradation of splice loss. The MCF includes four cores and a common cladding. Each core has adjacent relationships with two cores of remaining cores, an adjacent core interval Λ is from Λ.sub.nominal−0.9 μm to Λ.sub.nominal+0.9 μm, a common cladding diameter is from 124 μm to 126 μm, an MFD, λ.sub.cc and d.sub.coat at a wavelength of 1310 nm satisfy a predetermined relationship, the MFD is from a MFD-reference-value−0.4 μm to the MFD-reference-value+0.4 μm with the MFD-reference-value of from 8.6 μm to 9.2 μm, a zero-dispersion wavelength is from a wavelength-reference-value−12 nm to the wavelength-reference-value+12 nm with the wavelength-reference-value of from 1312 nm to 1340 nm, a dispersion slope at a zero-dispersion wavelength is 0.092 ps/(nm.sup.2.Math.km) or less, λ.sub.cc is 1260 nm or less, and a predetermined structural condition and an optical condition are satisfied.

Aspects of this disclosure relate to a cable that includes an outer housing, a plurality of optical fibers within the outer housing and arranged side-by-side along the width of the cable; and a removably attached access layer within the outer housing.

An optical cable including a load bearing core includes a longitudinally and radially extending slot housing at least one optical fibre, wherein the slot has a width providing a low clearance for the optical fibre(s) housed therein and preventing two optical fibres being stuck to one another; and the slot has a depth equal to or lower than a radius of the core.

The present disclosure includes: an optical fiber ribbon including a plurality of optical fibers having an outer diameter of 0.2 mm or less and a ribbon resin that integrates the plurality of optical fibers in a parallel state; and a coating resin that covers the optical fiber ribbon. The optical fiber ribbon is in an assembled form in which the plurality of optical fibers are assembled so that a length in an arrangement direction is shorter than that of a case where the optical fibers are arranged in a row, and the optical fiber ribbon is covered with the coating resin in the assembled form.

This MCF ensures sufficient manufacturing tolerance, is excellent in mass productivity, and is also capable of suppressing degradation of splice loss. The MCF includes four cores and a common cladding. Each core has adjacent relationships with two cores of remaining cores, an adjacent core interval Λ is from Λ.sub.nominal−0.9 μm to Λ.sub.nominal+0.9 μm, a common cladding diameter is from 124 μm to 126 μm, an MFD, λ.sub.cc and d.sub.coat at a wavelength of 1310 nm satisfy a predetermined relationship, the MFD is from a MFD-reference-value−0.4 μm to the MFD-reference-value+0.4 μm with the MFD-reference-value of from 8.6 μm to 9.2 μm, a zero-dispersion wavelength is from a wavelength-reference-value−12 nm to the wavelength-reference-value+12 nm with the wavelength-reference-value of from 1312 nm to 1340 nm, a dispersion slope at a zero-dispersion wavelength is 0.092 ps/(nm.sup.2.Math.km) or less, λ.sub.cc is 1260 nm or less, and a predetermined structural condition and an optical condition are satisfied.

An MCF or the like according to the present disclosure ensures sufficient manufacturing tolerance, is excellent in mass productivity, and is also capable of suppressing degradation of splice loss. The MCF includes four cores that extend along a central axis, and a common cladding. On a cross-section, the common cladding has a circular outer periphery, the four cores are arranged at positions to be line symmetric with respect to a straight line that intersects with a central axis and that intersects with none of the four cores, and a core arrangement defined by the four cores has rotational symmetry once with central axis being a center of rotation.