Abstract: The invention relates to an optical fiber preform (20) comprising a primary preform (21) and one or more purified silica-based overclad layers (22) surrounding said primary preform (21), the purified silica-based overclad layers (22) comprising lithium and aluminium, and having a ratio between lithium concentration [Li] and aluminium concentration [Al] satisfying the following inequality: 1×10?3?[Li]/[Al]?20×10?3.

Abstract: The invention concerns a method of SZ stranding into one strand a bundle of two or more flexible micromodules, each micromodule comprising one or more optical fibers. A first pulley is located with its winding surface adjacent to a longitudinal axis of a cabling line. The bundle of micromodules is guided over the winding surface of the first pulley, the first pulley being rotating around the longitudinal axis of the cabling line. The rotational speed, or the rotational direction of the first pulley, is alternating.

Abstract: The invention relates to a method for controlling rotation of a winding spool onto which an optical fiber is wound in a proof-testing machine. The optical fiber is guided in the proof-testing machine at a given line speed from an input pulling device to an output pulling device and then to the spool. The input and output pulling device is arranged to subject the optical fiber to a predetermined tensile stress. The method includes upon detection of a break between an output point (A) of the input pulling device and between an input point (B) of the output pulling device, a step of controlling the rotational speed of the spool to bring it to a complete stop; and a step of passing the optical fiber between an output point (C) of the output pulling device and an input point (D) of the winding spool in a fiber accumulation zone adapted to accumulate a predetermined fiber length preventing an fiber broken end resulting from the break going beyond the input point (D) of the winding spool.

Abstract: Few mode optical fibers for mode division multiplexing. The Few Mode Fiber supporting 25 or 30 LP guided modes and includes a graded index core with a ?-profile, a radius R1 (at 0 refractive index difference) between 21.5 and 27 ?m and a maximum refractive index difference Dn1 between 12.5×10?3 and 20×10?3, and an end of the ?-profile at a radius R1b, with index difference Dn1b; a trench surrounding the core with radius R3 between 30 and 42 ?m and refractive index difference Dn3 between ?15.10?3 and ?6.10?3, an intermediate depressed trench with a radius R2, with R1b<R2<R3 and a refractive index difference Dn2, with Dn3<Dn2<0, wherein: for |Dn1b?Dn2|>=0.5×10?3, Min(Dn1b, Dn2)??1.5×10?3, and for |Dn1b?Dn2|<0.5×10?3, Dn2 is between ?5×10?3 and ?3.5×10?3.

Abstract: Few mode optical fibers for mode division multiplexing. The Few Mode Fiber supporting 25 or 30 LP guided modes and includes a graded index core with a ?-profile, a radius R1 (at 0 refractive index difference) between 23 and 27 ?m and a maximum refractive index difference Dn1 between 14·10?3 and 17·10?3, and an end of the ?-profile at a radius R1b, with index difference Dn1b; a trench surrounding the core with radius R3 between 30 and 40 ?m and refractive index difference Dn3 between ?15·10?3 and ?6·10?3. Such a FMF shows a specific design of the interface between the core and the cladding such that R1b>R1, Dn1b between ?10·10?3 and ?3·10?3, and Dn1b?Dn3?0.9×10?3.

Abstract: Few mode optical fibers for mode division multiplexing. The Few Mode Fiber supporting 25 or 30 LP guided modes and includes a graded index core with a ?-profile, a radius R1 (at 0 refractive index difference) between 23 and 27 ?m and a maximum refractive index difference Dn1 between 14.10?3 and 17.10?3, and an end of the ?-profile at a radius R1b, with index difference Dn1b; a trench surrounding the core with radius R3 between 30 and 40 ?m and refractive index difference Dn3 between ?15.10?3 and ?6.10?3. Such a FMF shows a specific design of the interface between the core and the cladding such that R1b>R1, Dn1b between ?10.10?3 and ?3.10?3, and Dn1b?Dng?0.9×10?2.

Abstract: It is proposed a home optical data network formed of an optical fiber comprising an optical core and an optical cladding surrounding the optical core, the optical core having a refractive graded-index profile with a minimal refractive index n1 and a maximal refractive index n0, said optical fiber being such that it has a numerical aperture NA and an optical core radius a satisfying a criterion C of quality of optical communications defined by the following equation: C = NA - 0.02 × a where ? : NA = n 0 2 - n 1 2 = n 0 · 2 ? ? ? ? with ? ? ? = n 0 2 - n 1 2 2 ? n 0 2 , ? is the normalized refractive index difference, and in that said minimal and maximal refractive indexes n1, n0 and said optical core radius a are chosen such that NA>0.20, a>10 ?m and |C|<0.20.

Abstract: The invention relates to an optical fiber comprising an optical core and an optical cladding surrounding the optical core, the optical core having a single ? graded-index profile with ??1, and the optical core having a radius R1 and a maximal refractive index n0, said optical cladding having a refractive index nCl. Said optical cladding comprises a region of depressed refractive index ntrench, having an inner radius R2, with R2?R1, and an outer radius R3, with R3>R2. According to embodiments of the invention, the ?-value of said graded index profile and the optical core radius R1 are chosen such that R1?13.5 ?m and so as to satisfy a criterion C of quality. Thus, the invention provides a few-mode optical fiber, which allow guiding an increased number of LP modes as compared to prior art FMFs, while reaching the lowest Differential Mode Group Delay. The system reach is thus increased over prior art.

Abstract: A multimode optical fiber is provides, which includes an optical core and an optical cladding surrounding the optical core. The optical core has a refractive graded-index profile. The optical cladding includes: an inner layer surrounding the optical core, an intermediate layer, called a “depressed trench”, surrounding the inner layer, and an outer layer surrounding the depressed trench and having a constant refractive index. The depressed trench has a width W and a negative refractive index difference ?nt with respect to the outer layer, and is designed so as to satisfy the following inequality: |0.585677?114.681×S+13.7287×S2+18.7343×S×W?4.61112×S×?nt.103?0.913789×W×?nt.103|+2×W×?nt.103<?30 wherein: S is the width of the inner cladding, which is included between 0.6 ?m and 1.6 ?m; ?nt is included between ?11.10?3 and ?4.10?3; and W×?nt.103 is lower than ?25 ?m.

Abstract: It is proposed an optical fiber including an optical core and an optical cladding surrounding the optical core. The optical core has a refractive graded-index profile with a minimal refractive index n1 and a maximal refractive index n0. The optical fiber has a numerical aperture NA and an optical core radius ? satisfying a criterion C of quality of optical communications defined by the following equation: C=NA?0.02×a where: NA=?{square root over (n02?n12)}=n0·?{square root over (2?)} with ? = n 0 2 - n 1 2 2 ? ? n 0 2 , ? is the normalized refractive index difference. The minimal and maximal refractive indexes n1, n0 and the optical core radius a are chosen such that NA>0.20, a>10 ?m and |C|<0.20.

Abstract: The invention concerns a multimode optical fiber, with a graded-index core co-doped with at least fluorine F and germanium GeO2 and a refractive index profile with at least two ?-values. According to the invention, the concentration of fluorine F at the core center ([F]r=0) is between 0 and 3 wt % and the concentration of fluorine F at the core outer radius ([F],a) is between 0.5 wt % and 5.5 wt %, with [F]r=a?[F]r=>0.4 wt %. For wavelengths comprised between 850 nm and 1100 nm, said multimode optical fiber has an overfilled launch bandwidth (OFL-BW) greater than 3500 MHz·km and a calculated effective modal bandwidth (EMBc) greater than 4700 MHz·km over a continuous operating wavelength range greater than 150 nm.

Abstract: A method is proposed for access to optical fibers contained in an optical module, with a flexible structure for example, of an optical fiber transmission cable. The optical module includes a protective sheath in which the optical fibers are housed. Such a method includes: extracting the optical module from the transmission cable; degrading a portion to be stripped of the sheath of the optical module by heating to a specific temperature, for a predetermined duration; and accessing the optical fibers by stripping the portion to be stripped that has been degraded.

Abstract: An electric cable, in particular a data transmission cable, includes at least one line, in particular several twisted-pair lines, a screening sheet for the at least one line which screening sheet includes at least one substrate layer of a plastic material and at least one screening layer of an electrically conductive material, in particular metal, which the substrate layer is lined with, wherein the screening layer being provided with spacing gaps for electrical interruption thereof in a longitudinal strip direction, with the spacing gaps extending crosswise of the longitudinal strip direction and recurring at longitudinal intervals, an external envelope of an insulating material, and a semi-conductive shielding layer arranged between the screening sheet and the external envelope.

Abstract: The invention relates to an optical fiber preform (20) comprising a primary preform (21) and one or more purified silica-based overclad layers (22) surrounding said primary preform (21), the purified silica-based overclad layers (22) comprising lithium and aluminium, and having a ratio between lithium concentration [Li] and aluminium concentration [Al] satisfying the following inequality (Formula (I)). 1.103?[Li]/[Al]?20.

Abstract: An electric cable, in particular a data transmission cable, includes at least one line, in particular several twisted-pair lines, a screening sheet for the at least one line which screening sheet includes at least one substrate layer of a plastic material and at least one screening layer of an electrically conductive material, in particular metal, which the substrate layer is lined with, wherein the screening layer being provided with spacing gaps for electrical interruption thereof in a longitudinal strip direction, with the spacing gaps extending crosswise of the longitudinal strip direction and recurring at longitudinal intervals, an external envelope of an insulating material, and a semi-conductive shielding layer arranged between the screening sheet and the external envelope.

Abstract: The present invention embraces an optical fiber that includes a central core having a graded-index profile with respect to an outer cladding. The optical fiber also includes an inner cladding, a depressed trench, and an outer cladding. The optical fiber achieves reduced bending losses and a high bandwidth with a reduced cladding effect for high-data-rate applications.

Abstract: An amplifier optical fiber comprising a central core of a dielectric matrix doped with at least one element ensuring the amplification of an optical signal transmitted in the fiber and a cladding surrounding the central core and suitable for confining the optical signal transmitted in the core. The fiber also comprises metallic nanostructures suitable for generating an electronic surface resonance in the dielectric matrix of central core, the wavelength of said electronic surface resonance corresponding to an excitation level of the element ensuring the amplification.

Abstract: A buffer tube having therein a ribbon stack formed of optical fiber ribbons, and at least one filler ribbon provided on at least a top or bottom surface of the ribbon stack. The filler ribbon is provided to increase coupling between the ribbon stack and the buffer tube and to reduce fiber attenuation.

Abstract: A buffered optical fiber arrangement that includes a buffer tube in which is provided optical fibers and a texturized yarn coated with a water-swellable material. The filament diameter of the yarn used in the present invention may be between about 5 microns and about 100 microns, more preferably between about 10 and about 60 microns, still more preferably between about 20 and about 40 microns. The linear density, or denier in grams per 9000 meters, of the base yarn may be between about 100 and 1000, more preferably between about 200 and 600, or still more preferably between about 250 and 350. The degree of decrease in length (the “degree of texturizing”) between the perfectly straight filaments before texturizing and the texturized filament may be between 1 percent and 90 percent, more preferably between about 2 percent and 50 percent, or still more preferably between about 5 percent and 25 percent.

Abstract: A process for producing an optical fiber cable composite structural component, such as reinforcing members, buffer tubes, filler rods, jackets, and slotted cores, is disclosed. The composite structural components are produced by co-extruding a thermotropic liquid crystalline polymer (TLCP) and a thermoplastic matrix material into the composite structural component so that TLCP reinforcing fibrils are dispersed in the thermoplastic matrix material. The TLCP reinforcing fibrils undergo a high level of process induced orientation, are provided with a high aspect ratio, and small diameters. The composite structural component has a high modulus. The TLCP reinforcing fibrils may be made continuous or discontinuous.