The present disclosure provides ribbed and grooved sheath for optical fiber cables. An optical fiber cable (100) comprises one or more optical transmission elements (118) and a sheath (102) surrounding the one or more optical transmission elements (118). An outer surface of the sheath (102) has a plurality of ribs (104, 106, 108) and a plurality of grooves (110, 112) such that at least one groove has unequal groove width and/or at least one rib has unequal rib width. The plurality of ribs (104, 106, 108) is continuous and parallel on the outer surface. Alternatively, the plurality of ribs (104, 106, 108) is discontinuous.

An optical fiber cable may include a cable jacket, a central tube within the cable jacket, optical fibers within the central tube, and a number of semi-rigid rods around the central tube. Each rod may have a cross-sectional shape with an aspect ratio of at least 2:1. The rods may be helically applied around the central tube.

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.

Certain aspects of the present disclosure provide techniques for making armored cables. An example method for making an armored cable includes forming a strip stock into an armor tubing; welding a seam of the armor tubing in a welding zone; inserting at least one of a first optical fiber or a first wire into a first end of a first guide tube, wherein: the first guide tube extends through the welding zone; the first guide tube protects the at least one of the first optical fiber or the first wire during the welding of the seam; and the first guide tube is not part of the armored cable after the making of the armored cable; and supporting the first guide tube within the armor tubing by a plurality of support legs such that the first guide tube does not contact the armor tubing.

The present disclosure provides an optical fibre cable (100) with high blowing performance. The optical fibre cable (100) includes a plurality of optical fibres (102), a sheath (104) and one or more strength members (106). The sheath (104) envelops the plurality of optical fibres (102). The one or more strength members (106) are embedded in the sheath (104). The one or more strength members (106) embedded in the sheath (104) provides a blowing ratio to the optical fibre cable (100) in a range of about 20 to 45. The blowing ratio is a ratio of cross-sectional area of the sheath (104) to total cross-sectional area of the embedded strength members (106).

Embodiments of the disclosure relate to an optical fiber cable. The optical fiber cable includes a subunit having a first interior surface and a first exterior surface. The first interior surface defines a central bore along a longitudinal axis of the optical fiber cable. At least one optical fiber is disposed within the central bore of the subunit, and a plurality of strengthening yarns is disposed around the subunit. A cable sheath disposed around the plurality of strengthening yarns. The cable sheath has a second interior surface and a second exterior surface. The second exterior surface defines an outermost surface of the optical fiber cable. The cable sheath includes from 55% to 68% by weight of a mineral-based flame retardant additive and from 35% to 45% by weight of a polymer blend. The polymer blend includes a co-polyester or co-polyether and a polyolefin or a polyolefin elastomer.

A device for deciding characteristics of a differential signal cable at a transmission rate of not less than 10 G baud includes a selector switch that changes a transmission rate or an output power of a test signal to be supplied to the differential signal cable, a signal transmitting circuit that generates a test signal at a different transmission rate or output power as one of the predetermined number of plurality of test signals according to the change of state of the selector switches and sends the generated test signal to the differential signal cable via one connector, and a signal receiving circuit that receives the test signal transmitted through the differential signal cable via the other connector and decides the success or failure of transmission of the test signal through the differential signal cable based on the received test signal and pre-stored data of the plurality of test signals.

A fibre optic accessory for attachment to the end of an optical fibre is described, the fibre optic accessory comprising a plurality of grooves extending longitudinally along a portion of its outer surface. Using this accessory, an optical fibre to which this accessory is affixed may be installed in an installation tube with the use of a source of compressed air. A kit of parts for such an installation, an optical fibre and a method of installation are also described.

There are described methods and systems for deploying optical fiber within a conduit. In one aspect, an optical fiber injector comprising a pressure vessel having a fluid inlet and a fluid outlet. The fluid outlet is engaged with an open end of the conduit. A length of optical fiber is provided within the pressure vessel. The optical fiber is then jetted into the conduit by injecting a fluid into the pressure vessel via the fluid inlet. The optical fiber injector is configured such that the fluid is directed from the fluid inlet to the fluid outlet, and urges the optical fiber to move through the conduit, thereby deploying the optical fiber within the conduit. In a further aspect, there is provided a modular assembly comprising a pipeline and a line of two or more conduits arranged end-to-end. Each pair of opposing ends of adjacent conduits is connected together by a separate splice box. The line is positioned along and adjacent to a length of the pipeline.

An optical cable includes a main body and a termination segment extending from an end of the main body. The main body includes middle portions of optical fibers. The termination segment includes end portions of the optical fibers and multi-fiber connectors attached to the end portions of the optical fibers. The multi-fiber connectors are staggered along a length of the termination segment.