A multicore fiber includes: a cladding; a center core at a center of the cladding; and seven or more outer cores disposed at rotationally asymmetric positions on a circumference centered at the center of the cladding. Angles formed by adjacent ones of lines connecting the center core and respective ones of the outer cores are all 60° or less.

An optical fiber ribbon that includes 16-48 parallel optical fiber core wires and a connecting resin that connects adjacent optical fiber core wires. The outer diameter D of the optical fiber core wires is 160-220 μm, and when N is the number of optical fiber core wires and S is the bending strain of the optical fiber core wires, S=0.167×N/2(%) or less.

It is disclosed an optical fibre unit for air-blown installations comprising: a first group of optical fibres embedded in a resin layer; a sheath arranged in a radially outer position with respect to the resin layer so that an annular space is formed between resin layer and sheath; and a second group of optical fibres arranged in the annular space. Also disclosed are an apparatus and a method for manufacturing such optical fibre unit.

A fiber optic cable includes an optical fiber, a strength layer surrounding the optical fiber, and an outer jacket surrounding the strength layer. The strength layer includes a matrix material in which is integrated a plurality of reinforcing fibers. A fiber optic cable includes an optical fiber, a strength layer, a first electrical conductor affixed to an outer surface of the strength layer, a second electrical conductor affixed to the outer surface of the strength layer, and an outer jacket. The strength layer includes a polymeric material in which is embedded a plurality of reinforcing fibers. A method of manufacturing a fiber optic cable includes mixing a base material in an extruder. A strength layer is formed about an optical fiber. The strength layer includes a polymeric film with embedded reinforcing fibers disposed in the film. The base material is extruded through an extrusion die to form an outer jacket.

An optical fiber cable for providing enhanced sealing and enhanced access to an optical fiber for field terminations and/or splicing includes a jacket including a cavity extending along a length of the jacket and an optical fiber that is located in the cavity and extends the length of the jacket. The cavity is configured to have a length in a first direction that is greater than a width in a second direction that is perpendicular to the first direction. The jacket is configured to include a selectively teared portion that is located between the cavity and an outer surface of the jacket in the first direction such that the jacket is configured to tear along the length of the jacket at the selectively teared portion so as to allow for enhanced access to the optical fiber in the cavity, and the selectively teared portion created by the cavity is configured to permit the outer surface of the jacket to include a surface portion adjacent the selectively teared portion that is configured to provide enhanced sealing during operation of the optical fiber cable.

A filling composition comprises (A) a mineral oil having a kinematic viscosity from 80 cSt to 100 cSt at 40° C.; (B) a styrene-ethylene/propylene diblock copolymer; and (C1) a propylene/ethylene copolymer having a weight average molecular weight (M.sub.w) from 5,000 to 200,000 or (C2) an ethylene/propylene copolymer having a weight average molecular weight (M.sub.w) from 5,000 to 200,000. The filling composition is used as a filling composition in a buffer tube.

A cable includes a transmissive core; a jacket surrounding the transmissive core, which has at least an outermost polymeric layer; and an external semi-conductive layer around and in direct contact with the outermost polymeric layer of the jacket. The external semi-conductive layer is made of a composition comprising a base polymer material and an electrically conductive filler. The electrically conductive filler includes carbon nanotubes.

The present embodiment relates to a method of directly measuring a leakage loss from a peripheral core in a MCF with a coating to the coating. In the measurement method, in a high refractive-index state in which the coating is present on an outer periphery of a common cladding, first transmission power of measurement light, which propagates through the peripheral core of the MCF, is measured. On the other hand, in a low refractive-index state in which a low-refractive-index layer with a lower refractive index than the common cladding is provided on the outer periphery of the common cladding, second transmission power of the measurement light, which propagates through the peripheral core of the MCF, is measured. The leakage loss LL from the peripheral core to the coating is calculated as a difference between the first transmission power and the second transmission power.

An optical fiber cable includes: a cable body that includes an optical fiber; an external sheath that accommodates the cable body; a protective layer that is disposed between the cable body and the external sheath and that includes a first groove on an inner circumferential surface of the protective layer, wherein the first groove extends along an axial direction of the cable body; and a first ripcord disposed in the first groove and between the cable body and the protective layer.

The present invention relates to an optical fibre cable (100) and the method of manufacturing thereof. In particular, the optical fibre cable (100) comprises a plurality of optical fibres (102), one or more layers (104) enveloping the plurality of optical fibres (102), a metallic layer (108) surrounding one or more layers (104), an outer sheath (112), and a separation layer (110) sandwiched between the metallic layer (108) and the outer sheath (112). Particularly, binding between the metallic layer (108) and the separation layer (110) is defined as metal binding and binding between the separation layer (110) and the outer sheath (112) is defined as sheath binding. Further, the metal binding is less than the sheath binding.