Abstract: A method of determining characteristic spin parameters of a spun optical fiber by performing optical time-domain reflectometry measurements on the fiber, so as to obtain a state of polarization spatial function from a backscattered electromagnetic field, the state of polarization spatial function being defined by a plurality of components; and processing the state of polarization spatial function. The process includes calculating a further spatial function related to the spatial first derivative of at least one of the components of the state of polarization spatial function; identifying a spatial periodicity of the further spatial function; and determining the characteristic spin parameters as a function of the spatial periodicity.

Abstract: Optical cable, in particular for submarine connections. A water blocking resin filling composition of reduced hardness is disposed into interstices. Preferably, the resin composition is a polyurethane resin having less than about 35% by weight of a polyol/polyisocyanate mixture and about 60% to about 90% by weight of a mineral oil. The polyurethane resin preferably has less than about 12% by weight of a coupling agent. The cable has an optical core surrounded by a plurality of metallic wires and an outer polymeric sheath. The optical core is of the “tight” type with a plurality of optical fibers embedded into a polymeric matrix disposed around a strength member.

Abstract: An extrusion method and apparatus (11) for producing a cable (1, 101) including at least one core (7) comprising at least one transmissive element (2, 40), and at least one pair of coating layers (8, 9) arranged at a radially outer position with the respect of the core (7) are described. The method of the invention includes the simultaneous steps of depositing by co-extrusion at least one coating layer (8) of polymeric material and one coating layer (9) of expanded polymeric material and of maintaining a residual pressure not greater than the external pressure in a substantially annular interspace (21) defined between the coating layers. With respect to the methods of the prior art, the present invention allows to avoid the formation of bubbles at the interface between said at least one coating layer (8) of polymeric material and the coating layer (9) of expanded polymeric material, attaining an optimal adhesion between said layers (8, 9).

Abstract: 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.

Abstract: An electrical power transmission line having at least one electrical cable, a conduit of ferromagnetic material enclosing the electrical cable and having a base and a cover and electrical contact elements for electrically connecting the base and the cover, wherein the electrical contact elements are metal fusion joints or metal resilient members suitable to pierce the ferromagnetic material.

Abstract: A microstructured optical fiber has a core region with a material having a refractive index nco and a microstructured region surrounding the core region with a background material having a refractive index nm which is lower than the refractive index nco. The microstructured region has a plurality of microstructures having a refractive index different from the refractive index nm, wherein the distance ?? between the centers of any couple of adjacent microstructures is at least equal to about ?p and not higher than about 1.5?p, wherein ?p is the spatial variation length of the electric field intensity in the microstructured region.

Abstract: A method of building a cable termination is provided. The termination has an outer insulator body, a substantially longitudinally extended interior member having the electrical cable to be terminated, having a conductor for carrying load, an insulating material filled in a cavity between the outer insulator body and the interior member and means for accommodating volume expansions of the insulating material filled within the cavity. The cavity is created by introducing the interior member into the insulator body, filling the insulating material into the cavity and sealing the termination. A volume change compensation member having a predetermined volume to accommodate volume expansions of the insulating material within the cavity is placed into the cavity. Respective terminations are also provided.

Abstract: Electric power transport system having a cold dielectric superconducting cable, a cryostat and a cryogenic fluid. The cryostat has modules including an inner tube, an outer tube, a couple of gaskets, and a duct connected to the coupling surface between the gaskets of at least one flange with the environment external to the cryostat.

Abstract: 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.

Abstract: An optical fiber having an internal glass portion, a first coating layer surrounding the glass portion and a second coating layer surrounding the first coating layer. The first coating layer is formed from a cured polymeric material obtained by curing a radiation curable composition having a radiation curable oligomer having a backbone derived from polypropylene glycol and a dimer acid based polyester polyol. The cured polymeric material has: (a) a hardening temperature (Th) from ?10° C. to about ?20° C. and a modulus measured at the Th lower than 5.0 MPa; or (b) a hardening temperature (Th) from ?20° C. to about ?30° C. and a modulus measured at the Th lower than 20.0 MPa; or (c) a hardening temperature (Th) lower than about ?30° C. and a modulus measured at the Th lower than 70.0 MPa.

Abstract: An optical cable having an optical core with a strength member and optical fibers embedded in a thermoplastic material. The optical core has a joint section having substantially the same diameter as the one of the optical core. The joint section has a jointed strength member and a plurality of spliced optical fibers, the jointed portion of the strength member and the spliced portion of the optical fibers being embedded into a cured polymeric material. A method for manufacturing an optical core is also disclosed.

Abstract: Method and burner for increasing the deposition rate of porous glass deposit in the manufacture of optical preforms, by modifying the cross-sectional shape of the flow of glass particles impacting onto a target preform. In particular, the cross-section of the flow of glass particles is modified by increasing the dimension of the flow from a circular cross-section to one having a major and minor axis in a direction substantially perpendicular to the longitudinal axis of the target preform.

Abstract: A process and apparatus for elongating an optical fibre preform includes heating the preform so as to soften one region thereof; elongating the preform by submitting the preform to a traction; determining, during the step of elongating, the preform diameter in at least one measuring point along the preform; and controlling the step of elongating on the basis of the determined diameter. During the step of elongating, at least a geometrical parameter of the preform is measured, and the position of said diameter measuring point is controlled according to the measured geometrical parameter. Measuring at least a geometrical parameter of the preform may be accomplished by determining the profile of at least a portion of the softened region, e.g., an image of the neck region profile.

Abstract: A method, an extrusion apparatus and a plant for continuously manufacturing a communication cable. A plurality of twisted pairs of insulated conductors are housed in respective cavities longitudinally formed within an elongated integral body. The cavities have a substantially circular cross-section and maximum diameter adapted to prevent any relative movement of the twisted pairs of insulated conductors with respect to one another, while each of the pairs of insulated conductors is substantially free to move within the cavities along the longitudinal direction of the cable.

Abstract: An intermediate polymer preform of elongated shape for manufacturing a microstructured optical fibre is made from a mould with a tubular par containing a pattern of hole generating elements (wires, rods or tubes) extending along it. The hole generating elements are releasably attached to an upper and to a lower base of the mould. The mould is cleaned by circulating a filtered solvent in it. The mould is filled with a fluid polymer optical material or polymer precursor. The polymer material or precursor is consolidated so that it cannot change its shape under operating stress conditions at ambient temperature. The hole generating elements are released from the upper and lower base. The consolidated core preform is extracted from the mould. The process can further include calibrating the intermediate preform.

Abstract: An electrical power cable with a foamed, compressible, semiconductive insulation shield which serves as both a cushioning layer and an electrical shield.

Abstract: Optical fiber capable of controlling attenuation losses caused by microbending on the signal transmitted thereby. The optical fiber comprises: a) an internal glass portion; b) a first coating layer of a first polymeric material surrounding said glass portion; and c) a second coating layer of a second polymeric material surrounding said first coating layer, wherein said first polymeric material has a hardening temperature lower than ?10° C., an equilibrium tensile modulus lower than 1.5 MPa, wherein said first coating layer has a thickness of from 18 ?m to 28 ?m and wherein said second coating layer has a thickness of from 10 ?m to 20 ?m.

Abstract: A cable having at least one electrical conductor and at least one extruded covering layer based on a thermoplastic polymer material in admixture with a dielectric liquid. The thermoplastic polymer material is selected from: (a) at least one propylene homopolymer or at least one copolymer of propylene with at least one olefin comonomer; (b) a mechanical mixture of at least one propylene homopolymer or copolymer (a) and (c) at least one elastomeric copolymer or ethylene with at least one aliphatic ?-olefin, and optionally a polyene.

Abstract: A method for mechanically protecting a connection between at least two components forming part of an electrical and/or telecommunications network. At least one protective coating is provided, the coating being produced from an expanded polymeric material and providing the connection with a mechanical impact strength and ensuring a predetermined heat exchange between the connection and the external environment. This coating is axially and circumferentially continuous with respect to the connection. The present invention also relates to a coating for the mechanical protection of a connection between two components and to a joint thus protected.

Abstract: The present invention concerns a process for producting cables, in particular cables for the distribution of electrical energy or cables for telecommunications, more particularly, cables having at least one covering layer comprising a composition of high viscosity. More particularly, the present invention concerns cables having at least one covering layer comprising a polymeric composition comprising a mineral filler capable of imparting one or more specific properties to the aforesaid cables. In accordance with the present invention, said production process comprises the stages of: conveying at least one conducting element inside of an extruder; feeding the polymeric material, optionally premixed with other components of said composition, into said extruder, filtering the material transferred and plasticized by the screw of said extruder; depositing said material onto said at least one conducting element, the filtration operation being performed with a filtration efficiency greater than 0.