Alcatel

Draka Comteq B.v.

Draka Comteq France

Louis-Anne De Montmorillon

Pierre Sillard

Pascale Nouchi

Denis Molin

Ludovic Fleury

Marianne Bigot-Astruc

Maxime Gorlier

Florent Beaumont

Simon Richard

Pieter Matthijsse

Yves Lumineau

Frans Gooijer

David Boivin

Jean-Claude Rousseau

Ivo Flammer

Alain Pastouret

Franciscus Johannes Achten

Emmanuel Petitfrere

Raphaelle Sauvageon

Alain Bertaina

Jean-Fran&ccedil;ois Chariot

Bob J Overton

Ekaterina Burov

Lionel Expert

Pierre Sansonetti

Jean-Florent Campion

Lionel Provost

Marianne Bigot

Elise Regnier

Max Matau

Bruno Dany

Jean-Baptiste Trinel

Maxine Gorlier

Aurelien Bergonzo

Christine Labatut

The invention relates to an optical fibercomprising a coreand a claddingsurrounding the coreand having an outer diameter of 125 &#x3bc;m, the optical fibercomprising a cured primary coatingdirectly surrounding the claddingand a cured secondary coatingdirectly surrounding the cured primary coating, said cured primary coatinghaving a thickness tbetween 10 and 18 &#x3bc;m and an in-situ tensile modulus Emodbetween 0.10 and 0.18 MPa, said cured secondary coatinghaving a thickness tbetween 10 microns and 18 microns and an in-situ tensile modulus Emodbetween 700 and 1200 MPa, wherein said first and second thicknesses and said first and second in-situ tensile moduli satisfy the following equation:4%&#x3c;(modmod)/(modmod)&#x3c;50%.

Reduced diameter optical fiber and manufacturing method

The invention concerns a bending-loss single mode optical fibre having a Mode Field Diameter at 1310 nm greater than or equal to 9 microns and having a core and a cladding, the core refractive index profile having a trapezoid-like shape. According to an aspect of the invention, the cladding comprises a shallow trench with a refractive index difference Ant between &#x2212;2&#xd7;10; and &#x2212;0.9&#xd7;10, and: the trapezoid ratio r/rof the core is between 0.1 and 0.6, preferably, between 0.2 and 0.5, more preferably between 0.25 and 0.45; the core surface integral Formula (I) is between 20.10 3 &#x3bc;m and 24.10&#x3bc;m and the cladding surface integral Formula (II) is between &#x2212;25&#xd7;10&#x3bc;m and &#x2212;9&#xd7;10&#x3bc;m, where &#x394;n(r) is the refractive-index difference with respect to said outer cladding as a function of the radius r, and said single mode optical fibre fulfils the following criterion: 25.7&#xd7;10&#x2264;V&#x2212;0.2326V&#x2264;26.8&#xd7;10.

Bending-loss insensitive single mode fibre, with a shallow trench, and corresponding optical system

A few-mode optical fiber including a core's refractive-index profile &#x394;n(r) of trapezoid-like shape. The optical core having a center part of radius Rand a transition part ranges from the radius Rto a radius R, such that R&#x3e;Rwith Rbetween 6.8 and 11.5 &#x3bc;m, said refractive-index profile being defined by a surface integral of the core index profile of between 180&#xd7;10and 270&#xd7;10&#x3bc;m; a transition slope S of between 1.7&#xd7;10and 12&#xd7;10&#x3bc;m; with &#x394;nand &#x394;nthe refractive-index difference respectively of the center part of the optical core and of the cladding part adjacent to the optical core, with respect to the outer optical cladding.

Weakly-coupled few mode optical fibers for mode division multiplexing and corresponding optical transmission system

The invention relates to an optical fibercomprising a coreand a claddingsurrounding the coreand having an outer diameter of 125 &#x3bc;m, the optical fibercomprising a cured primary coatingdirectly surrounding the claddingand a cured secondary coatingdirectly surrounding the cured primary coating, said cured primary coatinghaving a thickness tbetween 10 and 18 &#x3bc;m and an in-situ tensile modulus Emodbetween 0.10 and 0.18 MPa, said cured secondary coatinghaving a thickness tlower or equal to 18 &#x3bc;m and an in-situ tensile modulus Emodbetween 700 and 1200 MPa, wherein said first and second thicknesses and said first and second in-situ tensile moduli satisfy the following equation: 4%&#x3c;(t&#xd7;t&#xd7;Emod&#xd7;Emod)/(t&#xd7;t&#xd7;Emod&#xd7;Emod)&#x3c;50%.

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.

Single mode fibre with a trapezoid core, showing reduced losses

Disclosed is a temperature and strain sensing optical fiber including a first doped radial zone (Z) with an associated first Brillouin shift (BS) caused by the doping of said zone (Z) and a second doped radial zone (Z) with associated second Brillouin shift (BS) caused by the doping of said second zone (Z). The concentration and/or composition of the doping materials in said first and second radial zones are chosen such that the first Brillouin Shift (BS) is different from the second Brillouin Shift (BS) for all variations of said Brillouin Shifts (BS, BS) caused by temperature and/or strain.

Temperature and strain sensing optical fiber and temperature and strain sensor

An amplifying optical fiber includes an inner core, an inner cladding, a depressed trench, and an outer cladding (e.g., an outer optical cladding). Typically, the inner core includes a main matrix (e.g., silica-based) doped with at least one rare earth element. The depressed trench typically has a volume integral Vof between about &#x2212;2200&#xd7;10&#x3bc;mand &#x2212;1600&#xd7;10&#x3bc;m. Exemplary embodiments of the amplifying optical fiber are suitable for use in a compact configuration and high power applications.

Rare-earth-doped amplifying optical fiber

An optical transmission fiber comprises a central core having an index difference &#x394;nwith an outer optical cladding; a first inner cladding having an index difference &#x394;nwith the outer cladding; and a second buried inner cladding having an index difference &#x394;nwith the outer cladding of less than &#x2212;3&#xb7;10. The second buried inner cladding moreover contains Germanium in a weight concentration of between 0.5% and 7%. The fiber shows reduced bending and microbending losses while exhibiting the optical performances of a standard single-mode fiber (SSMF).

Single mode optical fiber

An optical fiber includes a central core, which has a radius rand a refractive index n, and a surrounding optical cladding, which has a refractive index nsuch that n&#x3c;nand 0.31%&#x3c;((n&#x2212;n)&#xf7;n)&#x3c;0.55%. The optical cladding has at least five holes. These holes, which are positioned between about 9 microns and 17 microns from the central core, have a radius rsuch that 0.5r&#x2266;r&#x2266;r.

Single-mode optical fiber

An optical fiber having a core and an outer cladding, the core including from its center outward a central core having a radius and a refractive index difference with respect to the outer cladding, and a depressed inner cladding. The depressed inner cladding includes at least a first portion having a radius and a refractive index difference with respect to the outer cladding, the first portion preferably being adjacent to the central core, and a second portion adjacent to the first portion constituting a depressed trench having a radius, and a refractive index difference with respect to the outer cladding. The first portion of the inner cladding has a refractive index below the refractive index of the outer cladding, and the depressed trench has a refractive index that is lower than the refractive index of the first portion of the depressed inner cladding. The outer radius of the depressed inner cladding of the optical fiber is between 28 &#x3bc;m and 40 &#x3bc;m, the LPmode leakage losses at a wavelength of 1550 nm are less than 0.01 dB/km and the cable cut-off wavelength is less than 1530 nm.

Single mode optical fiber with depressed trench

The present invention embraces a single-mode optical fiber typically having reduced bending losses. The optical fiber includes a central core, an intermediate cladding, a buried trench, and an outer cladding. The optical fiber typically has (i), at a wavelength of 1310 nanometers, a mode field diameter with a nominal value of between about 8.6 microns and 9.5 microns (and a tolerance of &#xb1;0.4 micron), (ii) a cable cut-off wavelength of no more than 1260 nanometers, and (iii), for a bending radius of 15 millimeters at a wavelength of 1550 nanometers, bending losses of no more than 0.03 dB/turn.

A single-mode optical fiber includes a central core, an intermediate cladding, a depressed trench, and an external optical cladding. The central core has a radius rand a positive refractive index difference &#x394;nwith the optical cladding. The intermediate cladding has a radius rand a refractive index difference &#x394;nwith the optical cladding, wherein &#x394;nis less than &#x394;n. The depressed trench has a radius rand a negative index difference &#x394;nwith the optical cladding. At a wavelength of 1310 nanometers, the optical fiber has a mode field diameter (MFD) between 8.6 microns and 9.5 microns and, at a wavelength of 1550 nanometers, the optical fiber has bending losses less than about 0.25&#xd7;10dB/turn for a radius of curvature of 15 millimeters. At a wavelength of 1260 nanometers, attenuation of the LP11 mode to 19.3 dB is achieved over less than 90 meters of fiber.

Single-mode optical fiber having reduced bending losses

Disclosed is an improved, single-mode optical fiber possessing a novel coating system. When combined with a bend-insensitive glass fiber, the novel coating system according to the present invention yields an optical fiber having exceptionally low losses. The coating system features (i) a softer primary coating with excellent low-temperature characteristics to protect against microbending in any environment and in the toughest physical situations and, optionally, (ii) a colored secondary coating possessing enhanced color strength and vividness. The secondary coating provides improved ribbon characteristics for structures that are robust, yet easily entered (i.e., separated and stripped). The optional dual coating is specifically balanced for superior heat stripping in fiber ribbons, with virtually no residue left behind on the glass. This facilitates fast splicing and terminations. The improved coating system provides optical fibers that offer significant advantages for deployment in most, if not all, fiber-to-the-premises (FTTx) systems.

Microbend-resistant optical fiber

A single-mode optical fiber possesses, at a wavelength of 1550 nanometers, an effective area greater than about 90 pm2 without degradation of the optical fiber's other optical parameters. The single-mode optical fiber includes a central core, a first intermediate cladding, a second intermediate cladding, and an outer cladding. The optical fiber also has a cable cut-off wavelength of less than 1260 nanometers. Additionally, at a wavelength of 1310 nanometers, the optical fiber possesses a mode field diameter of between about 8.6 microns and 9.5 microns. Furthermore, the optical fiber possesses a zero chromatic dispersion wavelength of between about 1300 nanometers and 1324 nanometers and, at the zero chromatic dispersion wavelength, a dispersion slope of less than 0.092 ps/(nm2&#x2033;km).

A single-mode optical fiber includes a central core, a first inner cladding, a second inner cladding, and an outer cladding. The optical fiber, at a wavelength of 1550 nanometers, has an effective area greater than or equal to 100 &#x3bc;m. The optical fiber also has a cable cut-off wavelength less than 1260 nanometers. Additionally, the optical fiber possesses a zero chromatic dispersion wavelength of between about 1300 nanometers and 1324 nanometers and, at the zero chromatic dispersion wavelength, a dispersion slope of less than 0.092 ps/(nm&#xb7;km).

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Versailles, France

Louis-Anne De Montmorillon