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 cable includes: twisted optical fiber units each including a fiber group formed by optical fibers. At least one of the optical fiber units includes a filling that wraps an outer circumference of the fiber group.

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.

A fiber optic cable includes a cable core of core elements and a protective sheath surrounding the core elements, an armor surrounding the cable core, the armor comprising a single overlap portion when the fiber optic cable is viewed in cross-section, and a jacket surrounding the armor, the jacket having at least two longitudinal discontinuities extruded therein. A method of accessing the cable core without the use of ripcords includes removing a portion of the armor in an access section by pulling the armor away from the cable core so that an overlap portion separates around the cable core as it is being pulled past the cable core. A protective sheath protects the core elements as the armor is being pulled around the cable core.

In some aspects, polymeric yarns and communications cables incorporating the same are provided herein. Additionally, in some aspects, methods of producing polymeric yarns and communications cables incorporating the same are provided.

An optical cable includes: an optical fiber unit where a plurality of optical fibers are wrapped with a wrapping tape; at least three tensile strength members disposed in parallel with and on an outer side of the optical fiber unit at intervals in a circumferential direction; and a sheath that coats the optical fiber unit and the tensile strength members and that is disposed between the optical fiber unit and the tensile strength members. An inner wall surface of the sheath formed between the optical fiber unit and the tensile strength members protrudes toward a cable center in comparison with an inner wall surface of the sheath where none of the tensile strength members are disposed. A portion of the wrapping tape disposed on the inner wall surface that protrudes toward the cable center is depressed toward the cable center.

An image-conducting optical fiber bundle extends along a central bundle axis between image input and image output ends. The bundle is twisted along a portion of its length such that an image inputted into the image input end is angularly displaced about the central bundle axis before being outputted through the image output end. Each constituent optical fiber includes a cladding with a cladding diameter corresponding with the fiber diameter of that fiber and a core with a core diameter. The ratio of the core diameter to the cladding diameter defines a core-to-clad diameter ratio relative to each fiber. In various embodiments, at least one of fiber diameter and core-to-clad diameter ratio varies as a function of a fiber's radial displacement from the central bundle axis.

A method for producing an optical fiber unit by winding at least two bundling members on the outer circumference of an optical fiber bundle formed by bundling a plurality of optical fibers, including: feeding the optical fiber bundle from a fiber passage member; feeding the bundling members while forming intersection points between two of the bundling members on the outer circumference of the optical fiber bundle by feeding at least one of the bundling members from a bundling member passage part of a rotating member arranged to the outer circumference of the fiber passage member, while causing the rotating member to oscillate, with the feeding direction serving as the axis; and fusion-bonding the bundling members at their intersection points.

Provided is a method of manufacturing a downhole cable, the method including, forming a helical shape in an outer circumferential surface of a metal tube, the metal tube having a fiber element housed therein, and stranding a copper element in a helical space formed by the metallic tube. Also provided is a downhole cable including, a metallic tube having a helical space in an outer circumferential surface thereof, wherein the metallic tube has a fiber element housed therein, and a copper element disposed in a helical space formed by the steel tube. Double-tube and multi-tube configurations of the downhole cable are also provided.

The present disclosure relates to an optical unit including a tubular member, which accommodates a plurality of optical fibers and whose shape is variable to achieve an optimal space factor, to minimizes optical loss or the deterioration of optical properties when the optical cable is bent or compressed or external impact is applied, secure waterproof performance, and minimize an outer diameter, and an optical cable including the same.