A fiber optic cable assembly includes an elongate housing, a plurality of fiber optic cables placed inside the housing and extending longitudinally, and acoustic isolating material placed inside the housing and extending longitudinally. The acoustic isolating material includes a plurality of outwardly radially extending arms extending from a center of the housing towards a circumference of the housing. The plurality of arms divides a space inside the housing into a plurality of acoustically isolated sections. Each acoustically isolated section extends longitudinally. Each acoustically isolated section includes at least one of the plurality of fiber optic cables. Each acoustically isolated section is acoustically insulated from remaining sections of the plurality of acoustically isolated sections. A surface of the acoustic isolating material of each acoustically isolated section is covered by acoustic reflective material.

An optical fiber cable includes optical fiber ribbons, a slot rod and a cable jacket. The slot rod has slot grooves in which the optical fiber ribbons are housed. The cable jacket covers an outside of the slot rod. The optical fiber ribbons have, in a state in which optical fibers having an outer diameter of 0.22 mm or less are arranged in parallel, connecting portions at which adjacent ones of the optical fibers are connected to one another and non-connecting portions at which adjacent ones of the optical fibers are not connected to one another, which are provided intermittently in a longitudinal direction. A density of core number of the optical fibers included in the optical fiber cable is 4.8 cores/mm.sup.2 or more in a cross section of the optical fiber cable.

An optical fiber ribbon includes N pieces of optical fibers in a state of being disposed in parallel. At least some parts of the N pieces of optical fibers contact each other and are connected to each other by a resin; an outer diameter of the optical fiber is equal to or larger than 0.135 mm and equal to or smaller than 0.180 mm; a connection part connected by the resin or another resin and a non-connection part not connected by the resin or another resin are intermittently provided in a longitudinal direction between intermittently connected core wires of an optical fiber disposed at the Mth and an optical fiber disposed at the (M+1)th among the N pieces of optical fibers; the N is a multiple of 12; and the M is a multiple of 4.

An intermittent-connection-type optical fiber ribbon includes: a plurality of optical fiber core wires that are disposed in parallel; a connecting resin that is coated on surfaces of the plurality of optical fiber core wires; and slits that are provided intermittently in the connecting resin partially between the optical fiber core wires in a longitudinal direction, and a marking is on the connecting resin.

An intermittently-coupled type optical fiber ribbon in which a plurality of ribbon type paired optical fibers each of which is integrally formed by bringing two optical fibers into contact with each other are arranged in parallel, and a coupling part in which adjacent ribbon type paired optical fibers are connected to each other and a non-coupling part in which ribbon type paired optical fibers are not connected are intermittently provided in a longitudinal direction, wherein an outer diameter dimension of the optical fiber is 0.22 mm or less, and a center distance of optical fibers adjacent with the coupling part interposed therebetween between the adjacent ribbon type paired optical fibers is 0.280.03 mm.

A slot rod having a plurality of grooves for storing a plurality of optical fibers, a first layer disposed at a center of the slot rod, a second layer provided on an outer peripheral portion of the first layer, a third layer provided on an outer peripheral portion of the second layer, and an outermost layer provided on an outer peripheral portion of the third layer, and the third layer is formed of a material having higher adhesiveness to the outermost layer than a material in a case where the third layer is formed of the same material as the outermost layer.

Provided is an optical fiber cable whereby macrobend loss can be suppressed even when ribbons are mounted at high density in grooves. An optical fiber cable provided with optical units in which ribbons each having a plurality of optical fiber cores arranged in parallel are collected, a slot rod having a plurality of grooves for accommodating optical units, a tension member on which tension is applied, and a cable jacket for covering the outside of the slot rod. Each of the optical units is accommodated in the corresponding groove in a stranded state, and the occupancy of the optical units calculated from the cross-sectional area of the optical units with respect to the cross-sectional area of the groove is 25% to 65%.

An optical fiber unit includes: an optical fiber ribbon in which a plurality of optical fibers are arranged in parallel and connected to each other; a colored bundle tape longitudinally wrapped around an optical fiber ribbon bundle in which a plurality of the optical fiber ribbons are stranded together; and a colored bundle yarn spirally wound around the optical fiber ribbon bundle and the bundle tape.

An intermittent-connection-type optical fiber ribbon in which a plurality of optical fiber core wires are disposed in parallel, and which includes: a connecting part where adjacent optical fiber core wires are connected; and a non-connecting part where adjacent optical fiber core wires are not connected, the connecting parts and the non-connecting parts are provided intermittently in a longitudinal direction, the non-connecting parts are not provided in the longitudinal direction between two the optical fiber core wires, the connecting part is recessed, and in a case where, in the longitudinal direction, a is length of the connecting part, b is length of a part where the non-connecting part between different optical fiber core wires overlap, c is length of the non-connecting part, and p is an interval of the connecting parts, c/a1.5, b50 mm, and (c/a)p200 mm are set.

A fiber optic cable assembly includes an elongate housing, a plurality of fiber optic cables placed inside the housing and extending longitudinally, and acoustic isolating material placed inside the housing and extending longitudinally. The acoustic isolating material includes a plurality of outwardly radially extending arms extending from a center of the housing towards a circumference of the housing. The plurality of arms divides a space inside the housing into a plurality of acoustically isolated sections. Each acoustically isolated section extends longitudinally. Each acoustically isolated section includes at least one of the plurality of fiber optic cables. Each acoustically isolated section is acoustically insulated from remaining sections of the plurality of acoustically isolated sections. A surface of the acoustic isolating material of each acoustically isolated section is covered by acoustic reflective material.