Abstract: A submarine, optical-fiber cable having a central metal wire, a slotted rod surrounding the wires, an absorbent sheath surrounding the slotted rod, a plurality of strength members helically wound around the absorbent sheath, a metal jacket surrounding the strength members, and a plastic sheath surrounding the metal jacket. The slotted rod includes peripheral helical slots, and each of the slots may receive at least one optical fiber or at least one optical ribbon. The optical ribbon includes at least two optical fibers. Each of the optical fibers has a tensile strain ranging from about 0.015 to 0.3% along its axis. The absorbent sheath includes a layer surrounding and contacting the slotted rod for absorbing water. The cable is suitable for operating in deep sea beds for a long period of time, for laying and recovering cables, and for quick repair. Modulated strain distribution in the optical fibers suppresses stimulated Brillouin scattering therein.

Abstract: The present invention relates to a submarine optical fiber cable which is comprised of a plurality of relatively large diameter tension wires wound around an optical fiber unit in a close fitting manner so as to form a single layer which acts as a tension body, and root portions between the first tension wires caused by winding the first tension wires which covered by relatively small diameter second tension wires. Due to the second tension wires, deformation of the tension body of the stranded wires can be prevented and the pressure resistance and the tensile strength can be improved.

Abstract: Cross-sectionally fan-shaped metal segments 10a, 10b and 10c, shown in FIG. 1, are longitudinally assembled along an optical fibre to form a pressure-resistant sheath 10 for protecting an optical fibre unit for use in a transmission medium of a submarine optical fibre cable. The inner surfaces 11a, 11b, and 11c, shown in FIG. 1, of the metal segments 10a, 10b and 10c as well as all the contact faces 12a, 12b, and 12c also shown in FIG. 1 are so roughened that the adhesion force associated with the optical fibre unit 1 and the pressure-resistant sheath 10 and the metal segments themselves 10a, 10b and 10c can be strengthened enough to protect the optical fibre unit. Water penetration which may occur in case of cable damages can also be prevented.

Abstract: Disclosed herein is an optical fiber cable produced by pumping a two-liquid mixing and curing-type polyurethane resin which has the specified values in a tensile break strength, a breaking extension, a creep characteristics and the compression modulus of elasticity, in voids surrounding the optical fibers and those surrounding tension members of the cable.

Abstract: A submarine optical fiber cable includes inner and outer dams at suitable intervals for limiting water flow in the cable. The outer dams are formed in a space between inner and outer metal tubes of a pressure resisting sheath of the cable, and the inner dams are formed in the inner tube in which an optical fiber unit is enclosed. Each dam is made of a sticky compound or a jelly of plastics resin which is loaded at the dam position. The cable is also provided with a scale which represents distance from one end of the cable.