Abstract: The invention concerns a method for characterizing mode group properties of multimodal light traveling through an optical component, comprising: launching a reference pulse of light with a wavelength ?t from a light source into said optical component, collecting light signal output by said optical component into a Mode Group Separating optical fiber; detecting light signal output by said Mode Group Separating optical fiber. The Mode Group Separating optical fiber is a multimode fiber with an ?-profile graded index core with an ?-value chosen such that said fiber satisfies the following criterion at the wavelength ?t: ? ?? ? . L ? ? ? T REF > 4 where: ?? is a time delay difference between consecutive mode groups; L is a length of said fiber; ?TREF is a Full Width at Quarter Maximum of said reference pulse.

Abstract: A few mode optical fiber that includes an optical core and an optical cladding surrounding the optical core. The FMF has a step-index profile. The optical core has a core outer radius R1?7.5 ?m and a core refractive index difference ?n1 such that 14.5×10?3<?n1<24×10?3. The optical cladding comprises: an index ring with: a ring inner radius Rr1 between 12 ?m and 19 ?m; a ring refractive index difference ?nr such that ?n1/?nr is between 2 and 4; a ring volume Vring=??nr(Rr22?Rr12) between 1.8 ?m2 and 4.1 ?m2 where Rr2 is the ring outer radius; an inner cladding between the optical core and the index ring, with an inner cladding inner radius Ri1 and an inner cladding outer radius Ri2, the inner cladding having an inner cladding refractive index difference ?nclad1 between ?1.0×10?3 and 1.0×10?3.

Abstract: A multimode optical fiber (10) comprises an a-profile graded index core, a trench (13) surrounding the core (11) and an intermediate cladding (12) between the core and the trench. Such a multimode optical fiber (10) has: —A mode carrying capacity between 54 and 68 LP modes at 1060 nm, defined by a specific relationship between the numerical aperture of the core and the core radius, —A defined relationship between trench, core and intermediate cladding parameters to achieve a high bandwidth and low bend-loss at 1060 nm, and—A core radius between 24 and 26 ?m, a numerical aperture between 0.190 and 0.225 and a value of a between 2.01 and 2.05 to retain compatibility with legacy fibers.

Abstract: An optical fiber having an optical core and an optical cladding surrounding the optical core, the optical core having a single ? graded-index profile with ??1, ? being a non-dimensional parameter that defines the index profile shape of the optical core, and the optical core having a maximal refractive index nco at its center; the optical cladding has at its outer edge a refractive index nCl, and comprises a region of depressed refractive index ntrench, called a trench, with a negative refractive index difference ?nt=ntrench?nCl with respect to said optical cladding, the trench having an outer radius Rtrench. The optical core and cladding are configured to support propagation of at least six spatial modes and at maximum fifty-five spatial modes at an operating wavelength ?op between, and including, 1460 nm and 1675 nm, and the optical core satisfies an ovality criterion between 0.05 and 0.

Abstract: A few mode optical fiber that includes an optical core and an optical cladding surrounding the optical core. The FMF has a step-index profile. The optical core has a core outer radius R1?7.5 ?m and a core refractive index difference ?n1 such that 14.5×10?3<?n1<24×10?3. The optical cladding comprises: an index ring with: a ring inner radius Rr1 between 12 ?m and 19 ?m; a ring refractive index difference ?nr such that ?n1/?nr is between 2 and 4; a ring volume Vring=??nr(Rr22?Rr12) between 1.8 ?m2 and 4.1 ?m2 where Rr2 is the ring outer radius; an inner cladding between the optical core and the index ring, with an inner cladding inner radius Ri1 and an inner cladding outer radius Ri2, the inner cladding having an inner cladding refractive index difference ?clad1 between ?1.0×10?3 and 1.0×10?3.

Abstract: An optical fiber having an optical core and an optical cladding surrounding the optical core, the optical core having a single ? graded-index profile with ??1, ? being a non-dimensional parameter that defines the index profile shape of the optical core, and the optical core having a maximal refractive index nco at its center; the optical cladding has at its outer edge a refractive index nCl, and comprises a region of depressed refractive index ntrench, called a trench, with a negative refractive index difference ?nt=ntrench?nCl with respect to said optical cladding, the trench having an outer radius Rtrench. The optical core and cladding are configured to support propagation of at least six spatial modes and at maximum fifty-five spatial modes at an operating wavelength ?op between, and including, 1460 nm and 1675 nm, and the optical core satisfies an ovality criterion between 0.05 and 0.

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: A multimode optical fiber (10) comprises an a-profile graded index core, a trench (13) surrounding the core (11) and an intermediate cladding (12) between the core and the trench. Such a multimode optical fiber (10) has: A mode carrying capacity between 54 and 68 LP modes at 1060 nm, defined by a specific relationship between the numerical aperture of the core and the core radius, A defined relationship between trench, core and intermediate cladding parameters to achieve a high bandwidth and low bend-loss at 1060 nm, and A core radius between 24 and 26 ?m, a numerical aperture between 0.190 and 0.225 and a value of a between 2.01 and 2.05 to retain compatibility with legacy fibers.

Abstract: The invention concerns a method for characterizing mode group properties of multimodal light traveling through an optical component, comprising: launching a reference pulse of light with a wavelength ?t from a light source into said optical component, collecting light signal output by said optical component into a Mode Group Separating optical fiber; detecting light signal output by said Mode Group Separating optical fiber. The Mode Group Separating optical fiber is a multimode fiber with an ?-profile graded index core with an ?-value chosen such that said fiber satisfies the following criterion at the wavelength ?t: ? ?? ? . L ? ? ? T REF > 4 where: ?? is a time delay difference between consecutive mode groups; L is a length of said fiber; ?TREF is a Full Width at Quarter Maximum of said reference pulse.

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: The invention concerns a method for characterizing mode group properties of multimodal light traveling through an optical component, comprising: providing a Mode Group Separating optical fiber in an optical path between a light source and said optical component; launching reference pulses of light with a wavelength ?t from said light source through said Mode Group Separating optical fiber into said optical component at discrete intervals between a core center and a core radius of said fiber. The Mode Group Separating optical fiber is a multimode fiber with an ?-profile graded index core with an ?-value chosen such that said fiber satisfies the following criterion at the wavelength ?t: ? ?? ? · L ? ? ? T REF > 4 where: ?? is a time delay difference between consecutive mode groups; L is a length of said fiber; ?TREF is a Full Width at Quarter Maximum of said reference pulses.

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: 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: The invention relates to a method of measuring time delays with respect to differential mode delay of a multi-mode fiber or a few-mode fiber for at least two different wavelengths. The time delays for each wavelength are measured before the single mode fiber is translated to a next radial offset.

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.