Alcatel

Draka Comteq B.v.

Alain Bertaina

Pierre Sillard

Louis-Anne De Montmorillon

Pascale Nouchi

Maxime Gorlier

Jean-Claude Rousseau

Raphaelle Sauvageon

Bruno Dany

Jean-Fran&ccedil;ois Chariot

Ludovic Fleury

Florent Beaumont

Lionel Expert

Maxine Gorlier

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 field of the invention is that of chromatic dispersion compensation modules and of methods of designing chromatic dispersion compensation modules. The design method includes an optimization step consisting in reducing an original quality criterion. The compensation optical fiber of the module has a chromatic dispersion less than a first threshold and chromatic dispersion sufficiently negative for the quality criterion to be less than a second threshold.

Chromatic dispersion compensation module

The field of the invention is that of chromatic dispersion compensation modules and of methods of designing chromatic dispersion compensation modules. The design method includes an optimization step consisting in reducing an original quality criterion at a chosen constant average figure of merit for the compensation optical fiber by increasing the attenuation of the compensation optical fiber. The compensation optical fiber of the module has chromatic dispersion more negative than a first threshold and, for a given figure of merit, attenuation that is sufficiently high for the quality criterion to be less than a second threshold and a quality-to-price ratio criterion to be less than a third threshold.

The invention relates to a single-mode optical fiber that, for a wavelength of 1550 nm, has an effective area greater than or equal to 60 &mgr;m , chromatic dispersion lying in the range 3 ps/(nm.km) to 14 ps/(nm.km), a chromatic dispersion gradient in the range 0 ps/(nm .km) to 0.1 ps/(nm .km), and a ratio between the effective area and the chromatic dispersion gradient that is greater than or equal to 1000 &mgr;m .nm .km/ps, as well as a zero chromatic dispersion wavelength shorter than 1480 nm. The fiber thus has both a large effective area and a shallow chromatic dispersion gradient, and it is thus well suited to wavelength division multiplexed (WDM) transmission. The invention also relates to a WDM optical fiber transmission system that uses such a fiber as the line fiber.

Optical fibre with optimized ratio of effective area to dispersion scope for optical fibre transmission system with wavelength multiplexing

The invention provides a monomode optical fiber having, at a wavelength of 1550 nm: an effective section area greater than or equal to 60 &mgr;m ; chromatic dispersion close to 8 ps/(nm.km); a chromatic dispersion slope of absolute value less than 0.07 ps/(nm .km). In the range of wavelengths used in a WDM transmission system, typically 1530 nm to 1620 nm, the fiber has chromatic dispersions greater than 7 ps/(nm.km), thereby making it possible to limit non-linear effects. The invention also provides a WDM optical fiber transmission system using such a fiber as a line fiber. The small slope of its chromatic dispersion is an advantage in such a system.

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Paris, France

Alain Bertaina