Alcatel

Jean-Claude Rousseau

Marianne Paillot

Louis-Anne De Montmorillon

Pascale Nouchi

Raphaelle Sauvageon

Jean-Fran&ccedil;ois Chariot

Alain Bertaina

Michel Hertz

Jean-Francois Chariot

The invention relates to a dispersion-shifted single-mode optical fiber having an effective area greater than or equal to 60 &mgr;m . This fiber is characterized by the fact that it has a zero chromatic dispersion wavelength &lgr; that is greater than 1585 nm and chromatic dispersion at 1550 nm that is greater in absolute terms than 3 ps/nm.km. The invention is applicable to wavelength division multiplexed transmission systems, and makes it possible to limit non-linear effects, such as four-wave mixing, and to limit the use of dispersion-compensating fiber.

Dispersion-shifted single-mode optical fiber optimized for high data rates

The invention relates to a dispersion shifted monomode optical fiber which, in the wavelength range 1400 nm to 1650 nm, presents both a chromatic dispersion maximum and a chromatic dispersion slope of absolute value less than 0.05 ps/nm &middot;km. Advantageously, the maximum in the wavelength wave 1400 nm to 1650 nm is a single maximum. The fiber also presents dispersion having a slope of absolute value less than 0.03 ps/nm &middot;km in the wavelength range 1530 nm to 1580 nm. The fiber of the invention is particularly suitable for wavelength division multiplexed transmission systems.

Optical fiber having a chromatic dispersion slope that is shallow

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 concerns a monomode optical fiber having at a wavelength of 1550 nm a dispersion slope from &minus;0.8 ps/nm .km to &minus;0.5 ps/nm .km and a chromatic dispersion from &minus;130 ps/nm.km to &minus;90 ps/nm.km, the fiber having a cladding and a core whose index profile features a central part having an index higher than that of the cladding, a ring having an index higher than that of the cladding and lower than that of the central part, and a trench between the central part and the ring having an index lower than that of the cladding, and the use of a fiber of this kind to compensate dispersion. The fiber of the invention finds applications in high bit rate transmission systems in particular. The invention also concerns a wavelength division multiplex optical fiber transmission system comprising at least one section of fiber in accordance with the invention.

Dispersion compensating fiber for wavelength division multiplexed optical fiber transmission systems using dispersion shifted fiber as line fiber

A monomode dispersion shifted optical fibre having an effective core area greater than 100 &mgr;m , characterized in that it has a chromatic dispersion cancellation wavelength &lgr; from 1 400 nm to 1 500 nm and low curvature losses.

Phase-shifted monomode optical fibre with large effective area

The invention relates to a dispersion-shifted optical fiber comprising a core and cladding, with an index profile of shape consisting of a rectangular central portion surrounded by an annular portion of index lower than the index of the cladding, and then by the cladding, with a zero chromatic dispersion at a wavelength value &lgr; lying in the range 1380 nm to 1450 nm, and with chromatic dispersion at 1550 nm lying in the range 8 ps/nm&middot;km to 12 ps/nm&middot;km. The invention also relates to the use of such an optical fiber in a wavelength division multiplexed system.

Optical fiber useful for wavelength multiplexing transmission system

The invention relates to a dispersion-shifted single-mode optical fiber having an effective area greater than or equal to 60 &mgr;m . This fiber is characterized by the fact that it has a zero chromatic dispersion wavelength &lgr; lying in the range 1400 nm to 1480 nm, and bending losses of less than 0.05 dB at 1550 nm for a winding of 100 turns of the fiber around a radius of 30 mm. The invention is applicable to wavelength division multiplexed transmission systems, and makes it possible to limit non-linear effects, such as four-wave mixing, and to limit the use of dispersion-compensating fiber.

Monomode optical fiber with optimized dispersion shift for high speeds

Single mode dispersion-shifted optical fiber comprising an external refractive index ring

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.

Line fiber for WDM optical fiber transmission systems

A stepped index optical fiber is disclosed having a chromatic dispersion cancellation wavelength less than 1 280 nm or even 1 250 nm. The fiber can be used for wavelength-division multiplex transmission not only in the window around 1 550 nm but also in the window around 1 300 nm. The chromatic dispersion in the second window enables transmission without excessively penalizing non-linear effects. A fiberoptic transmission system which uses the above fiber as line fiber is also disclosed.

Broadband stepped index optical fiber

The invention relates to a dispersion-shifted single-mode fiber having cladding of given refractive index (n ) and a fiber core having an index profile that is in the shape of a trapezium, a triangle, or a rectangle, together with a first ring, the index profile of the fiber core having an outer, second ring of index (n ) greater than the index of said cladding (n ), said fiber being characterized in that the index (n ) of said second ring is greater than or equal to the index (n ) of said first ring. The invention provides better control over the wavelength at which chromatic dispersion is zero, while conserving the other transmission characteristics of known fibers, such as mode diameter and attenuation.

Single mode dispersion-shifted optical fiber with external refractive index ring

In a method of shrinking a tubular optical fiber preform with a doped silica core the preform is placed on a glassmaking lathe to rotate it about an axis, a torch is moved parallel to the axis in front of the preform to shrink it and collapse it in a number of passes, and during an etching pass a mixture of oxygen and a fluorine precursor gas is injected through one end of the incompletely collapsed preform to eliminate a certain layer from the core. During the etching pass, a certain value of the pressure of the gaseous mixture at the end of the preform is determined and the speed of the torch is slaved to this pressure value. Controlling the speed of the torch stabilizes the pressure of the gaseous mixture inside the preform, which longitudinally homogenizes the diameter of the core and the refractive index difference relative to an optical cladding around the core.

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Chatou, France

Jean-Claude Rousseau