Fiber optic cables suitable for use in downhole applications, with one or more features for inhibiting flow of any fluid breaching an armor layer of the optical cable are provided. By preventing, or at least impeding, fluid flow along the cable length, any breaching fluid may be confined to a small region of the cable, which may significantly reduce the deleterious effects (e.g., hydrogen darkening) of an armor layer breach. One example optical cable generally includes one or more optical fibers, an inner tube surrounding the one or more optical fibers, an outer tube surrounding the inner tube, and one or more polymer sealing features disposed in an annulus between the outer tube and the inner tube and bonded to at least one of the inner tube or the outer tube to prevent fluid flow in the annulus along at least a portion of a length of the optical cable.

An optical fiber cable manufacturing method using a manufacturing apparatus including an SZ twisting device, an extrusion molding device, and a pressing portion disposed between the SZ twisting device and the extrusion molding device is provided. The method including: twisting optical fibers or optical fiber units in an SZ manner using the SZ twisting device to form an optical fiber bundle; and covering the optical fiber bundle with a sheath using the extrusion molding device while pressing the optical fiber bundle using the pressing portion.

A method of making a microstructured optical fiber including loading the core and cladding materials of the fiber with hydrogen and deuterium at a loading temperature; annealing the fiber at a selected temperature T.sub.anneal; pumping the fiber with radiation; and reducing the temperature of the fiber and storing the fiber at the reduced temperature before the step of pumping the fiber; and wherein the method allows the hydrogen and the deuterium to become bound to the core material and the cladding material.

A method of making a microstructured optical fiber including loading the core and cladding materials of the fiber with hydrogen and deuterium at a loading temperature; annealing the fiber at a selected temperature T.sub.anneal; pumping the fiber with radiation; and reducing the temperature of the fiber and storing the fiber at the reduced temperature before the step of pumping the fiber; and wherein the method allows the hydrogen and the deuterium to become bound to the core material and the cladding material.

A method of making a microstructured optical fiber including loading the core and cladding materials of the fiber with hydrogen and deuterium at a loading temperature; annealing the fiber at a selected temperature T.sub.anneal; pumping the fiber with radiation; and reducing the temperature of the fiber and storing the fiber at the reduced temperature before the step of pumping the fiber; and wherein the method allows the hydrogen and the deuterium to become bound to the core material and the cladding material.

A hybrid cable applicable in oil wells is disclosed, comprising a FIMT, a conductor layer formed by continuous laser welding and cylindrically covered the outer surface of the FIMT, the outer cylindrical surface of the conductor layer being covered with a high temperature resistant insulating layer by a continuous extrusion method or by wrapped helically with insulating tapes around the outer surface of the conductor layer and the external steel tube cylindrically covered the outer surface of the insulating layer. The conductor layer is coaxial with the FIMT, the inner space of the hybrid cable to accommodating excess length of the optical fiber for thermal expansions or the tensile stress of the optical cable. The thickness of the insulating layer cylindrically covered the outer surface of the conductor layer can be increased, thereby improving the insulating property. A method of manufacturing such hybrid cable is disclosed.

Fiber optic cables suitable for use in downhole applications, with one or more features for inhibiting flow of any fluid breaching an armor layer of the optical cable are provided. By preventing, or at least impeding, fluid flow along the cable length, any breaching fluid may be confined to a small region of the cable, which may significantly reduce the deleterious effects (e.g., hydrogen darkening) of an armor layer breach. One example optical cable generally includes one or more optical fibers, an inner tube surrounding the one or more optical fibers, an outer tube surrounding the inner tube, and one or more polymer sealing features disposed in an annulus between the outer tube and the inner tube and bonded to at least one of the inner tube or the outer tube to prevent fluid flow in the annulus along at least a portion of a length of the optical cable.

Fiber optic cables suitable for use in downhole applications, with one or more features for inhibiting flow of any fluid breaching an armor layer of the optical cable are provided. By preventing, or at least impeding, fluid flow along the cable length, any breaching fluid may be confined to a small region of the cable, which may significantly reduce the deleterious effects (e.g., hydrogen darkening) of an armor layer breach. One example optical cable generally includes one or more optical fibers, an inner tube surrounding the one or more optical fibers, an outer tube surrounding the inner tube, and one or more polymer sealing features disposed in an annulus between the outer tube and the inner tube and bonded to at least one of the inner tube or the outer tube to prevent fluid flow in the annulus along at least a portion of a length of the optical cable.

A method of making a microstructured optical fiber including loading the core and cladding materials of the fiber with hydrogen and deuterium at a loading temperature; annealing the fiber at a selected temperature T.sub.anneal; pumping the fiber with radiation; and reducing the temperature of the fiber and storing the fiber at the reduced temperature before the step of pumping the fiber; and wherein the method allows the hydrogen and the deuterium to become bound to the core material and the cladding material.

This optical fiber cable comprises an optical unit obtained by creating strands of a plurality of optical fiber tape cores, a tube in which the optical unit is housed, and a cable sheath that covers the outside of an aggregate of a plurality of tubes. The optical fiber tape cores have provided thereto, between some or all of optical fiber cores when a plurality of optical fiber cores are positioned in parallel, and intermittently in the longitudinal direction thereof, connecting parts that connect adjoining optical fiber cores, and non-connecting parts at which adjoining optical fiber cores are not connected. The tube has a Young's modulus lower than the Young's modulus of the cable sheath, and the aggregate is such that the plurality of tubes on the inside of the cable sheath deform elastically with respect to one another, with some thereof being in surface contact with the cable sheath.