Alcatel

Draka Comteq B.v.

Alcatel N.v.

Alcatel Fibres Optiques

Alcatel Submarine Networks

Alcatel Submarcom

Alcatel Cable France

Alcatel Fibers Optiques

Pascale Nouchi

Louis-Anne De Montmorillon

Pierre Sillard

Ludovic Fleury

Florent Beaumont

Maxime Gorlier

Frans Gooijer

Denis Molin

Marianne Bigot-Astruc

Yves Lumineau

Pieter Matthijsse

Jean-Claude Rousseau

Pierre Sansonetti

Olivier Audouin

Franciscus Johannes Achten

Jean-Pierre Hamaide

Cedric Gonnet

Ivo Flammer

Emmanuel Petitfrere

Elise Regnier

Alain Bertaina

Raphaelle Sauvageon

Jean-Fran&ccedil;ois Chariot

Lionel Expert

Andre Tardy

Jean-Florent Campion

Emmanuel Desurvire

Claude Brehm

Lionel Provost

Christian Le Sergent

Jean-Yves Boniort

Jacques Auge

Max Matau

Rosine Meilleur

Maxine Gorlier

Christine Labatut

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

A method for manufacturing an optical fiber preform includes the steps of depositing an inner cladding and a central core inside a fluorine doped silica tube and thereafter collapsing the silica tube to form a primary preform. The fluorine doped silica tube has a cross section area that is no more than about 15 percent smaller than the cross section area of the resulting primary preform. The present method facilitates reduced-cost manufacturing of a high-capacity optical fiber preform, which may be drawn to produce an optical fiber having reduced transmission losses.

Method for manufacturing an optical fiber preform

An optical fiber preform comprises a primary preform that includes at least one inner cladding and a central core deposited inside a fluorine doped silica tube. The fluorine doped silica tube has a cross section area that is no more than about 15 percent smaller than the cross section area of the primary preform. The optical fiber preform has a large capacity, may be manufactured at reduced cost, and may be drawn to produce an optical fiber having reduced transmission losses.

Optical fiber preform

Disclosed is an optical transmission fiber having reduced bending and microbending losses that is commercially usable in FTTH or FTTC transmission systems.

Single-mode optical fiber

An optical transmission fiber comprises a central core having an index difference &#x394;with an outer optical cladding; a first inner cladding having an index difference &#x394;with the outer cladding; and a second buried inner cladding having an index difference &#x394;with 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 whilst exhibiting the optical performances of a standard single-mode fiber (SSMF).

A method for manufacturing a final optical fiber preform via overcladding of a primary preform having a cross section area is disclosed. The method includes at least one manufacturing step of the primary preform by deposit of an inner cladding and of a central core inside a tube of fluorine-doped silica, the tube being chosen such that it has a cross section area that is maximally about 15% less than the cross section area of the primary preform. With the method of the invention it is possible to manufacture a preform of large capacity at reduced cost which allows the drawing of an optical fiber having reduced transmission losses.

An optical transmission fiber includes 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;3.10. 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 whilst exhibiting the optical performances of a standard single-mode fiber (SSMF).

The invention relates to methods of producing and improving an optical transmission line comprising the combination of a line optical fiber and an original or modified module for compensating the chromatic dispersion of said line optical fiber. The modified compensation module is a module for compensating chromatic dispersion of a line optical fiber () in a plurality of contiguous and non-overlapping spectral bands each covering at least 30 nanometers, the module including a structure () carrying a plurality of submodules () at least one of which is separable from the structure (), which are disposed in series, which are interconnected by one or more connections () identifiable to the naked eye without optical measurement and accessible from the exterior without damaging the module, and each of which includes a support to which is fixed at least one optical fiber () for compensating chromatic dispersion, at least one optical fiber () of said plurality of compensation optical fibers () having a compensation ratio from 0.9 to 1.1 for the center wavelength of one of said spectral bands, and at least two submodules () having compensation optical fibers () of different kinds.

Method of producing and improving an optical transmission line, and associated compensation modules

The invention relates to the field of optical fibers for wavelength division multiplex transmission networks. It provides an optical fiber with chromatic dispersion compensation in the S band from 1 460 nm to 1 530 nm having a negative chromatic dispersion at the wavelength of 1 495 nm and at least three core slices, preferably at least four core slices. The single core slice or the first core slice is very deeply buried and preferably has as at the wavelength of 1 495 nm a chromatic dispersion to dispersion slope ratio whose absolute value is from 68 nm to 158 nm.

Optical fiber with chromatic dispersion compensation in the S band

The invention relates to a multiband chromatic dispersion compensation optical fiber comprising successively, from the center toward the periphery, a central slice whose maximum index is higher than the index of the cladding, a buried slice whose minimum index is lower than the index of the cladding, and an annular slice whose maximum index is higher than the index of the cladding and lower than the maximum index of the central slice, a cladding of constant index, and having, on the one hand, at the wavelength of 1550 nm, firstly a chromatic dispersion of less than &#x2212;8 ps/nm.km, secondly a chromatic dispersion to dispersion slope ratio whose absolute value is greater than 750 nm, and thirdly a mode diameter greater than 5 &#x3bc;m, and on the other hand, at the wavelength of 1625 nm, bending losses for a radius of 10 mm that are less than 400 dB/m.

Chromatic dispersion compensation optical fiber

The invention proposes an optical fiber presenting a reference index profile having more than six steps. At a wavelength of 1550 nm it presents chromatic dispersion that is positive, and a ratio of the square of effective area over chromatic dispersion slope that is greater than 100,000 &#x3bc;m.nm.km/ps. The invention makes it possible to improve the propagation characteristics of prior art fibers by optimizing index profile. It can be implemented using conventional techniques for building up preforms by VAD or by MCVD.

Optical fiber of complex index profile

The dispersion managed optical fiber () far use in wavelength division multiplex transmission networks includes longitudinally alternating positive and negative chromatic dispersion optical fiber portions and includes a core having a varying index profile and a cladding having a constant index. Each optical fiber portion (T+, T&#x2212;) has at a wavelength of 1550 nm a chromatic dispersion whose absolute value is from 1 ps/nm.km to 10 ps/nm.km, a chromatic dispersion slope whose absolute value is less than 0.015 ps/nm.km, and an effective area greater than 35 &#x3bc;m. The relative effective area difference at a wavelength of 1550 nm between the positive and negative chromatic dispersion optical fiber portions is less than 7%, and each optical fiber portion (T+, T&#x2212;) has bending losses at a wavelength of 1625 nm less than 0.1 dB for 100 turns with a diameter of 60 mm.

Dispersion managed optical fiber

The invention relates to a dispersion-compensating optical fiber for use in wavelength division multiplex transmission systems, said fiber including successively, from the center toward the periphery, a core having a varying index profile and then a cladding having a constant index, enabling the propagation, for a given operating spectral range greater than 30 nm, of at least one higher-order mode in addition to the LPfundamental mode, the index profile of the core being determined so that, for said higher mode, and for said operating spectral range, the chromatic dispersion is less than &#x2212;150 ps/nm.km, the chromatic dispersion slope is negative, the effective area is greater than 40 &#x3bc;m, the difference between the wavelength corresponding to the overall minimum chromatic dispersion outside the operating spectral range and the wavelength corresponding to the upper limit of the operating spectral range is greater than 35 nm, and the relative variation of the dispersion slope over the operating spectral range has an absolute value less than 30%.

Dispersion-compensating fiber using a higher-order mode

Growing community of inventors

Ville d'Avray, France

Pascale Nouchi