Abstract: The invention relates to an optical fiber for compensating, in-line, for the chromatic dispersion of an optical fiber having positive chromatic dispersion. For a wavelength of 1550 nm, the optical fiber of the invention advantageously has chromatic dispersion that is negative and greater than −40 ps/(nm.km), a chromatic dispersion gradient that is negative, a chromatic dispersion to chromatic dispersion gradient ratio that is in the range 50 nm to 230 nm, an effective area that is greater than 10 &mgr;m2, and bend losses that are less than or equal to 0.05 dB; and a cutoff wavelength that is greater than or equal to 1.1 &mgr;m. It makes it possible to compensate for the cumulative chromatic dispersion in a line fiber of the NZ-DSF type having positive chromatic dispersion. The invention also relates to an optical fiber transmission system using such a fiber to compensate, in-line, for the cumulative chromatic dispersion in the line fiber.

Abstract: The invention provides a step index optical fiber which presents cladding having an index lower than the index of silica and a core with an index higher than the index of silica. The fiber is obtained by drawing a preform made by chemical vapor deposition using a deposition tube of index lower than the index of silica. Inner cladding of index substantially equal to the index of the deposition tube, and then a core of index higher than the index of the inner cladding are deposited in succession therein. The invention makes it possible to obtain a fiber having a large effective area, reduced attenuation, and suitable for being fabricated at low cost by chemical vapor deposition.

Abstract: A monomode dispersion shifted optical fibre having an effective core area greater than 100 &mgr;m2, characterized in that it has a chromatic dispersion cancellation wavelength &lgr;0 from 1 400 nm to 1 500 nm and low curvature losses.

Abstract: The line optical fiber of the system is single-mode and has a very large effective mode area accompanied by high chromatic dispersion and/or a steep spectrum gradient of said dispersion. Compensation means are associated with said fiber so as to compensate at least a major portion of said dispersion and/or of said gradient. They are integrated into repeater units distributed along the transmission line. The invention applies to telecommunications.

Abstract: The invention relates to a dispersion-shifted single-mode optical fiber having an effective area greater than or equal to 60 &mgr;m2. This fiber is characterized by the fact that it has a zero chromatic dispersion wavelength &lgr;0 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.

Abstract: A chromatic dispersion-compensating fiber adapted to compensate the chromatic dispersion of an SMF or an NZ-DSF having positive chromatic dispersion presents chromatic dispersion which is negative and greater than or equal to −150 ps/(nm.km) at a wavelength of 1550 nm, and a theoretical cutoff wavelength longer than 1800 nm. At 1550 nm, the fiber presents a ratio of chromatic dispersion over chromatic dispersion slope lying in the range 30 nm to 500 nm. The fiber can present a rectangle or a trapezium profile together with a buried trench and a ring. It can be used in a line or in a module to compensate the chromatic dispersion and the chromatic dispersion slope in transmission systems in which the line fiber is an SMF or an NZ-DSF having positive chromatic dispersion.

Abstract: The invention proposes providing an optical fiber transmission system with a dispersion compensating fiber 12l to 12n to compensate the chromatic dispersion and chromatic dispersion slope of the line fiber 6l to 6n; the dispersion compensating fiber satisfies the following criteria: 1 C g C g ′ × 1 1 + C cum / ( L g · C g ′ · Δ ⁢   ⁢ λ ) ≤ C C ′ ≤ C g C g ′ × 1 1 - C cum / ( L g · C g ′ · Δ ⁢   ⁢ λ ) ( 1 ) &LeftBracketingBar; C ′ C ′′ &RightBracketingBar; ≥ Max ⁡ ( Δ ⁢   ⁢ λ 2 × ( C · C g ′ C ′ · C g × ( 1 ± C cum L g · C g ′ · Δ ⁢   ⁢ λ ) - 1 ) - 1 ) ( 2 )

Abstract: At a wavelength of 1 550 nm an optical fiber has a chromatic dispersion from −12 to −4 ps/(nm.km) and a ratio of chromatic dispersion to chromatic dispersion slope from 250 to 370 nm. Its index profile comprises a rectangle or trapezium with a buried trench and a ring. An optical fiber transmission system uses this kind of fiber to compensate cumulative chromatic dispersion in a line fiber that has at a wavelength of around 1 550 nm a chromatic dispersion from 5 to 11 ps/(nm.km) and a ratio of chromatic dispersion to chromatic dispersion slope from 250 to 370 nm.

Abstract: A chromatic dispersion-compensating fiber adapted to compensate the chromatic dispersion of a step index monomode fiber in band S presents chromatic dispersion of less than −40 ps/(nm·km) around 1475 nm, chromatic dispersion slope of less than −0.16 ps/(nm2·km), and an effective area greater than or equal to 14 &mgr;m2 around said wavelength value. The fiber is monomode at 1475 nm. The fiber can present a rectangle profile with a buried trench and a ring. It serves to compensate chromatic dispersion and chromatic dispersion slope for transmission systems in band S using a step index monomode fiber as the line fiber.

Abstract: 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;m2; chromatic dispersion close to 8 ps/(nm.km); a chromatic dispersion slope of absolute value less than 0.07 ps/(nm2.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.

Abstract: An optical fiber exhibiting monomode behavior in-cable over a range from 1300 nm to 1625 nm and having, at a wavelength of 1550 nm:

Abstract: The invention relates to a method of fabricating an optical fiber with improved control of transmission characteristics. It proposes determining variations in the characteristics of the preform departing from the design characteristics and modifying the diameter of the fiber during drawing as a function of the measured variations. By varying the diameter of the fiber, variations in the preform departing from its design values can be compensated, in other words irregularities of the preform can be smoothed out. This variation limits the effect of preform variations on the propagation characteristics of the fiber.

Abstract: A monomode optical fiber in a cable for an optical fiber transmission network with wavelength division multiplexing and a utilization range extending from 1300 nm to 1625 nm, and presenting at a wavelength of 1550 nm:

Abstract: An optical fiber for compensating chromatic dispersion of a positive chromatic dispersion optical fiber has at a wavelength of 1 550 nm a chromatic dispersion less than −40 ps/(nm.km), a ratio between the chromatic dispersion and the chromatic dispersion slope in the range from 50 nm to 230 nm, an effective area greater than or equal to 12 &mgr;m2 and curvature losses less than or equal to 0.05 dB. It is used for in-line compensation of cumulative chromatic dispersion in a positive chromatic dispersion line fiber. A fiber optic transmission system is also disclosed using a fiber of this kind to compensate the cumulative chromatic dispersion in the line fiber.