Abstract: 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.

Abstract: 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.

Abstract: 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 ?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 ?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.

Abstract: The field is that of methods for providing fiber-optic final preforms obtained by external plasma overcladding build-up around a primary preform. The method involves providing a final preform starting from a primary preform by external plasma deposition of silica grain over a primary preform, the outer peripheral layer of the primary preform consisting of a fluorine-doped silica tube. The build-up process involves forming a first overcladding using fluorine-doped synthetic silica grain followed by a second overcladding step using natural silica grain. The optical fibers obtained and their associated optical fiber preforms are also disclosed.

Abstract: 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 ?m4.nm2.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.

Abstract: The dispersion managed optical fiber (1) 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?) 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/nm2.km, and an effective area greater than 35 ?m2. 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?) has bending losses at a wavelength of 1625 nm less than 0.1 dB for 100 turns with a diameter of 60 mm.

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: 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 ?m4.nm2.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.

Abstract: 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 ?m4.nm2.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.

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: An optical fiber has three or four core slices including one or more buried slices and a raised central slice. The buried slice or each of the buried slices is very deeply buried. The fiber has a zero dispersion wavelength of less than 1 460 nm. It has a chromatic dispersion in the vicinity of 5 ps/nm.km and a dispersion slope in the vicinity of 0.03 ps/nm2.km at a wavelength of 1 550 nm.

Abstract: The fiber is adapted to compensate chromatic dispersion and chromatic dispersion slope of a positive chromatic dispersion optical fiber in the U band from 1625 nm to 1675 nm. In that band it has negative chromatic dispersion, negative chromatic dispersion slope, and a chromatic dispersion over chromatic dispersion slope ratio from 100 nm to 600 nm. At a wavelength of 1650 nm it has bending losses less than 100 dB/m with the fiber wound around a 10 mm radius former and bending losses less than 5×10?3 dB with 100 turns of the fiber wound around a 30 mm radius former. The dispersion compensating fiber can be used to produce broadband transmission systems for signals with wavelengths up to 1675 nm.

Abstract: An optical fiber in which propagation is monomode propagation when incorporated into a cable has, at a wavelength of 1 550 nm, a chromatic dispersion from 3 ps/(nm.km) to 14 ps/(nm.km) and an absolute value of chromatic dispersion slope less than 0.014 ps/(nm2.km), and, at a wavelength of 1 625 nm, bending losses measured for a 10 mm radius less than 400 dB/m. The proposed criteria allow use of the fiber over a wide band of wavelengths in a wavelength division multiplex transmission system. The low chromatic dispersion slope simplifies the management of chromatic dispersion in the transmission system.

Abstract: The invention provides a fiber with continuously changing chromatic dispersion; it limits the quantity of dispersion-compensating fiber needed in a transmission system to compensate the cumulative chromatic dispersion in the line fiber. The fiber has a higher chromatic dispersion at a first end than at the other end, referred to as the second end. The chromatic dispersion varies along the fiber, decreasing over at least a portion of the fiber. At the first end the chromatic dispersion can be of the order of the dispersion of a conventional line fiber, i.e. close to 8 ps/(nm.km). At the second end the chromatic dispersion can have a value of the order of 4 ps/(nm.km). The fiber is used as the line fiber in a transmission system at the beginning of a section between two repeaters.

Abstract: 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.

Abstract: 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 −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 &mgr;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.

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: An optical fiber has three or four core slices including one or more buried slices and a raised central slice. The buried slice or each of the buried slices is very deeply buried. The fiber has a zero dispersion wavelength of less than 1 460 nm. It has a chromatic dispersion in the vicinity of 5 ps/nm.km and a dispersion slope in the vicinity of 0.03 ps/nm2.km at a wavelength of 1 550 nm.

Abstract: 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.

Abstract: The field of the invention is that of optical fibers for use in wavelength division multiplex transmission networks.