摘要:
A telecommunication fiber optic cable for gas pipeline application has a built-in leakage detecting device. The cable has an optical core including a number of telecommunication optical fibers, an outer jacket covering the optical core, and one or more gas leakage detector optical fibers. One or more gas leakage detector optical fibers are enclosed within the outer jacket. Preferably, the cable has a linearly extending rod reinforcing system having strength rods that force the cable to bend in a preferential bending place. Preferably, the leakage detector optical fibers are located at, or close to, a plane that is substantially orthogonal to the preferential bending plane and passing through the cable neutral axis.
摘要:
An optical cable is manufactured in a single continuous process starting directly from at least an optical preform, by means of a fiber/cable integrated manufacturing line including a fiber(s) drawing assembly for the production of one or more optical fibers from respective optical preforms, and a cabling assembly for producing the optical cable from the optical fiber(s), the cabling assembly comprising a fiber buffering assembly for the application of a loose or tight coating to the optical fiber(s), and a strengthening and sheathing sub-assembly for applying one or more reinforcing and protective layers to the buffered optical fiber(s).
摘要:
A telecommunication optical fiber cable and in particular a reduced diameter optical cable with improved installation features for use in the end part of an access telecommunication network. The optical fiber cable has a number of optical fibers; at least a core tube containing the optical fibers; a jacket surrounding the core tube; and at least one strength rod spaced from the central axis, the cable having a twisting stiffness G*Jp, wherein G is the elastic shear modulus; and Jp is the polar moment of inertia of a cable section, wherein the twisting stiffness G*Jp is lower than or equal to 0.10 Nm2, preferably lower than or equal to 0.05 Nm2, and more preferably lower than or equal to 0.02 Nm2. The cable is profitably installable by a blown method.
摘要:
A telecommunication fiber optic cable for gas pipeline application has a built-in leakage detecting device. The cable has an optical core including a number of telecommunication optical fibers, an outer jacket covering the optical core, and one or more gas leakage detector optical fibers. One or more gas leakage detector optical fibers are enclosed within the outer jacket. Preferably, the cable has a linearly extending rod reinforcing system having strength rods that force the cable to bend in a preferential bending place. Preferably, the leakage detector optical fibers are located at, or close to, a plane that is substantially orthogonal to the preferential bending plane and passing through the cable neutral axis.
摘要:
The invention relates to a radiation curable colored coating composition for coloring a coated optical fiber wherein the coating, when disposed and cured to surround an optical fiber coated with an internal coating, and when said colored fiber is coated with a matrix material and assembled into an optical fiber ribbon, said colored coating has a degree of adhesion to the internal coating which is higher than the degree of adhesion to the matrix material and said optical fiber assembled into said optical fiber ribbon shows, upon aging for at least two weeks in water at 60° C., an increase in the attenuation of the transmitted signal at 1550 nm of less than 0.05 db/km with respect to the attenuation of the assembled optical fiber measured before aging. The invention also relates to said colored coating composition when used in an optical fiber ribbon.
摘要:
A method and apparatus for manufacturing an optical cable comprising at least one metal tube housing at least one optical fiber and having a predetermined excess fiber length (EFL) is described. In this method the metal tube is plastically deformed and shortened by a predetermined amount (St) greater than the predetermined EFL and is plastically deformed after shortening to provide a controlled elongation thereof so as to reach the predetermined excess fiber length. An optical cable so manufactured has a local excess fiber length (EFL) varying of or less than 0.2% along the longitudinal extension of the cable with respect to an average EFL of the cable.
摘要:
A method and apparatus for manufacturing an optical cable comprising at least one metal tube housing at least one optical fiber and having a predetermined excess fiber length (EFL) is described. In this method the metal tube is plastically deformed and shortened by a predetermined amount (St) greater than the predetermined EFL and is plastically deformed after shortening to provide a controlled elongation thereof so as to reach the predetermined excess fiber length. An optical cable so manufactured has a local excess fiber length (EFL) varying of or less than 0.2 % along the longitudinal extension of the cable with respect to an average EFL of the cable.
摘要:
An optical cable for communication includes at least one micromodule, wherein the micromodule is blocked with respect to the propagation of water. The at least ones micromodule includes at least one optical fiber, a retaining element for housing the at least one optical fiber, and a thixotropic filling compound arranged within the retaining element. The filling compound is thixotropic, has a viscosity higher than or equal to 700 Pa-s at zero shear rate and at a first temperature of 20° C., a loss modulus G″ lower than or equal to 3000 MPa at 1 Hz and at a second temperature of −45° C., and is compatible with the retaining element.
摘要:
An optical fiber cable has a highly reduced diameter. The cable has a central strength member; a number of tubes containing loosely arranged optical fibers, each tube having a thickness, and each optical fiber having a coating; and a protective outer jacket, wherein the filling coefficient of optical fibers in at least one loose tube is ≧45°/0. The tubes are made of a material having an elasticity modulus ≧700 MPa; and the optical fibers are SM-R fibers having a microbending sensitivity ≦4.0 dB·km−1/g·mm−1 at a temperature of about −30° C. to +60° C. at about 1550 nm.
摘要:
An optical cable having at least one element for the transmission of optical signals and a structure that is able to protect the at least one element. The structure is a multilayer structure and is arranged in a position radially external to the at least one element and has a) at least one first covering layer of polymeric material in a position radially external to the at least one element; b) at least one covering layer of foamed polymeric material in a position radially external to the at least one first covering layer, and c) at least one second covering layer of polymeric material in a position radially external to the at least one covering layer of foamed polymeric material. The foamed polymeric material has a density between 0.3 and 0.7 kg/dm3 and tensile modulus at 20° C. between 300 and 700 MPa.