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: The invention relates to an optical fiber 1 comprising a core 2 and a cladding 3 surrounding the core 2 and having an outer diameter of 125 ?m, the optical fiber 1 comprising a cured primary coating 4 directly surrounding the cladding 3 and a cured secondary coating 5 directly surrounding the cured primary coating 4, said cured primary coating 4 having a thickness t1 between 10 and 18 ?m and an in-situ tensile modulus Emod1 between 0.10 and 0.

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: The invention concerns a single mode optical fiber having a core and a cladding, the core refractive index profile having a trapezoid-like shape. According to an aspect of the invention, the transition part of the trapezoid-like core refractive index profile is obtained by gradually changing a concentration of at least two dopants from a concentration in said center part of said core to a concentration in a cladding part adjacent to said core.

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: 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: A method of qualifying an effective bandwidth of a multimode optical fiber at a first wavelength ?1, using DMD data of the fiber measured a second wavelength ?2. Data representative of a Radial Offset Delay, a Radial Offset Bandwidth and a Relative Radial Coupled Power of the fiber are derived from the DMD data at the second wavelength ?2. A transformation is performed on the ROD data and ROB data at the second wavelength ?2 to obtain corresponding ROD data and ROB data at the first wavelength ?1. An effective bandwidth of the fiber at the second wavelength ?2 is computed using the ROD data and the ROB data at the first wavelength ?1 and the {tilde over (P)}DMD data at the second wavelength ?2.

Abstract: A method for selecting wide-band multimode optical fibers from a single wavelength, the method comprising the following steps of, for each multimode optical fiber obtaining a first DMD plot using a measurement of DMD carried out at a first single wavelength, obtaining from the first DMD plot, a first multimode fiber specification parameter; and for each fiber: obtaining from the first DMD plot, a curve representative of a radial offset delay, called ROD curve, as a function of the radial offset value; applying a linear fit on the ROD curve for at least two radial offset value ranges; obtaining from the linear fit and for each radial offset value range, an average radial offset delay slope, called ROD slope; selecting the multimode optical fibers meeting a first predetermined specification criterion for the first multimode fiber performance parameter, and for which the at least two computed ROD slopes meet a predetermined slope criterion.

Abstract: Disclosed is a method of characterizing a multimode optical fiber link including a light source and two or more multimode fibers. The method includes a step of characterizing each of said multimode fibers using a measurement of the Dispersion Modal Delay (DMD) for each of said multimode fibers, and delivering, for each of said multimode fibers, at least three fiber characteristic curves as a function of a radial offset value r; a step of characterizing the light source by at least three source characteristic curves showing at least three parameters of the source as a function of a fiber radius r and obtained by a technique similar to the DMD measurement; and a step of computing an Effective Bandwidth (EB) of the link, comprising calculating a transfer function using both each of said source characteristic curves and each of said at least three fiber characteristic curves for each of said multimode fibers.

Abstract: The invention relates to an optical link comprising N optical fibers, with N?2. Each optical fiber comprises an optical core and an optical cladding surrounding the optical core, the optical core having a single ?i graded-index profile with ?i?1, and the optical core having a radius R1i, where i E [1; N] is an index designating said optical fiber. Said optical cladding comprises a region of depressed refractive index ntrenchi, called a trench, surrounding the optical core. According to embodiments of the invention, for all optical fibers in said link, said optical core radius R1i and said length Li are chosen such that R1i?13.5 ?m and so as to satisfy a criterion C of quality. Thus, the invention provides a few-mode optical fiber link, which allow guiding an increased number of LP modes as compared to prior art FMF links, while reaching low Differential Mode Group Delay.

Abstract: The invention concerns a multimode optical fiber, with an ct-profile graded-index core with an a-value between 1.96 and 2.05 and a N value defined as N=(R1/?)2(n12?n02) between 7 and 52, where R1 is the multimode core radius, n1 is the maximum index of the multimode core and n0 is the minimum index at the outer edge of the graded index core. According to the invention, a depressed region directly surrounds the graded/index core and satisfies the criteria: ?2.20<Dn2<0, where Dn2 is the index difference of depressed region with external cladding, and 220 Ln(N)?1100<V2<220 Ln(N)?865, where V2 is the volume of the depressed region. Such a multimode fiber shows an increased OFL-bandwidth above 10000 Hz·km at an operating wavelength between 950 nm and 1310 nm.

Abstract: A hybrid optical fiber integrates features of multimode optical fibers and single-mode optical fibers. The hybrid optical fiber possesses an optical core having a first core region and a second core region to provide improved optical mode coupling ratio for single-mode transmission while maintaining a broad bandwidth for multimode transmission. The hybrid optical fiber's optical core may optionally include a depressed trench positioned between the optical core's first core region and the optical core's second core region to reduce modal dispersion and to improve modal bandwidth during multimode transmissions.

Abstract: The invention concerns a method of characterizing a multimode optical fiber link comprising a light source and a multimode fiber, which comprises: a step (170) of characterizing the multimode fiber using a measurement of the Dispersion Modal Delay (DMD) and delivering fiber characteristic data; a step (171) of characterizing the light source by at least three source characteristic curves showing three parameters of the source as a function of a fiber radius r and obtained by a technique similar to the DMD measurement; a step (173) of computing an Effective Bandwidth (EB) of the link, comprising calculating (172) a transfer function using both the fiber characteristic data and each of said source characteristic curves.

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]r=?) is between 0.5 wt % and 5.5 wt %, with [F]r=??[F]r=0>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: Disclosed is a method of characterizing a multimode optical fiber link including a light source and two or more multimode fibers. The method includes a step of characterizing each of said multimode fibers using a measurement of the Dispersion Modal Delay (DMD) for each of said multimode fibers, and delivering, for each of said multimode fibers, at least three fiber characteristic curves as a function of a radial offset value r; a step of characterizing the light source by at least three source characteristic curves showing at least three parameters of the source as a function of a fiber radius r and obtained by a technique similar to the DMD measurement; and a step of computing an Effective Bandwidth (EB) of the link, comprising calculating a transfer function using both each of said source characteristic curves and each of said at least three fiber characteristic curves for each of said multimode fibers.

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 concerns a multimode optical fiber, with an ct-profile graded-index core with an a-value between 1.96 and 2.05 and a N value defined as N=(R1/?)2(n12?n02) between 7 and 52, where R1 is the multimode core radius, n1 is the maximum index of the multimode core and n0 is the minimum index at the outer edge of the graded index core. According to the invention, a depressed region directly surrounds the graded/index core and satisfies the criteria: ?2.20<Dn2<0, where Dn2 is the index difference of depressed region with external cladding, and 220 Ln(N)?1100<V2<220Ln(N)?865, where V2 is the volume of the depressed region. Such a multimode fiber shows an increased OFL-bandwidth above 10000 Hz·km at an operating wavelength between 950 nm and 1310 nm.

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]r=?) is between 0.5 wt % and 5.5 wt %, with [F]r=??[F]r=0>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: The invention relates to a method for qualifying the actual effective modal bandwidth of a multimode optical fiber over a predetermined wavelength range, comprising the steps of: carrying out (30) a Dispersion Modal Delay (DMD) measurement of the multimode optical fiber at a single wavelength to obtain an actual DMD plot; generating (32) at least two distinct modified DMD plots from the actual DMD plot, each modified DMD plot being generated by applying to the recorded traces a temporal delay ?t that increases in absolute values with the radial offset value roffset, each modified DMD plot being associated with a predetermined bandwidth threshold (S1; S2); for each modified DMD plot, computing (33) an effective modal bandwidth as a function of said modified DMD plot and comparing (34) the computed effective modal bandwidth (EMBc1; EMBc2) with the bandwidth threshold value to which the modified DMD plot is associated; (35) qualifying the actual effective modal bandwidth as a function of results from the compari

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]r=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.