Methods and apparatus to control the acoustic properties of optical cables used as in-well oil and gas probes for acoustic monitoring, such as distributed acoustic sensing (DAS). One example aspect provides a solid path for the acoustic wave to propagate from an outside armor layer of the cable to the sensing optical waveguide embedded therein. Another example aspect offers ways to spatially dispose the optical sensing elements to create response delays indicative of the propagation speed and/or direction of an acoustic wave. Yet another example aspect provides ways to utilize additional spectral interrogation to increase ultimate spatial resolution. Yet another example aspect provides ways to locally vary the acoustic properties along the length of the cable.

An optical cable includes an optical module which includes first optical fibers and a first retaining element arranged about the first optical fibers. The module also includes second optical fibers arranged about the first retaining element, the second optical fibers being arranged on at least one circumference concentric with the first retaining element. The module also includes a second retaining element arranged about the second optical fibers, which is also substantially coaxial with the first retaining element. This optical module with coaxial retaining elements and fibers has a particularly high fiber density, while preserving the possibility to uniquely identify all the fibers.

An optical communication cable subassembly includes a cable core having optical fibers each comprising a core surrounded by a cladding, buffer tubes surrounding subsets of the optical fibers, and a binder film surrounding the buffer tubes. Armor surrounds the cable core, the binder film is bonded to an interior of the armor, and water-absorbing powder particles are provided on an interior surface of the binder film.

Embodiments of the disclosure relate to an optical fiber cable. The optical fiber cable includes a cable jacket having an interior surface and an exterior surface. The interior surface defines a central bore extending along a longitudinal axis of the optical fiber cable, and the exterior surface defines an outermost surface of the optical fiber cable. The optical fiber cable also includes a cable core including at least one optical fiber disposed within the central bore of the cable jacket. The cable jacket includes at least one access feature made of a first polymeric material disposed between the interior surface and the exterior surface. The first polymeric material has a first tensile strength (TS.sub.1). Each of the at least one access feature is surrounded by a second polymeric material of the cable jacket. The second polymeric material has a second tensile strength (TS.sub.2). TS.sub.1≤(2/3)*TS.sub.2.

An optical fiber cable that includes subunits is provided. Optical fiber cables are used to transmit data over distance. The subunits are twisted and stranded within the cable to reduce degradation of stranding during use of the cable. The subunits of one or more optical fiber cables are arranged in complimentary configurations that counteract their varying asymmetrical forces to provide an improved handling performance for the optical fiber cable.

The present invention relates to an optical fiber cable (200) with a different binder pitch comprising a plurality of tubes (204) with one or more optical transmission elements (202), a first binder (208) and a second binder (210) wound around the plurality of tubes (204) helically. The first lay length of the first binder (208) is different than a second lay length of the second binder (210) and a lay ratio of the first lay length to the second lay length is equal to or more than 1.2. And the difference between a first stranding angle and a second stranding angle of the first binder (208) and the second binder (210) respectively is greater than or equal to 5 degrees.

Embodiments of the disclosure relate to a bundled drop assembly. The bundled drop assembly includes a central member. The bundled drop assembly also includes an inner layer of subunits laid in a winding direction around the central member. The inner layer of subunits includes at least one subunit containing one or more optical fibers. Further, the bundled drop assembly includes at least one further layer of subunits laid around the inner layer of subunits in a same winding direction as the inner layer of subunits. The at least one further layer of subunits includes at least one subunit containing one or more optical fibers. The at least one further layer of subunits includes an outer layer of subunits that is the outermost layer of the bundled drop assembly.

A jacket is provided to the outer circumference of a cable core, a rip cord, and a tension member. The cable core, the rip cord, and the tension member are collectively covered by the jacket. A wrapping tape is longitudinally placed on the outer circumference of a core part so as to be wound therearound. Thus, immediately after the wrapping tape is longitudinally placed and wound, a wrap part thereof is formed so as to lie substantially straight in the axial direction of an optical fiber cable. In contrast, in an optical fiber cable, the cable core is obtained by combining and intertwining the core part and the wrapping tape. Because of this configuration, the wrap part of the wrapping tape is helically disposed in the longitudinal direction.

This optical fiber cable is a central-core-type cable in which slotted rods are not used, and is composed of a core, a wrapper, a tension member, a ripcord, a sheath, and the like. The core is formed by twisting together a plurality of optical fiber units without back-twisting. The optical fiber units are formed by twisting together a plurality of intermittently-fixed optical fiber ribbons. A direction in which the optical fiber ribbons are twisted together is same as a direction in which the optical fiber units are twisted together.

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.