Abstract: An optical fiber transmission system having Raman amplifier module for inputting a pumping signal into an optical fiber for stimulated Raman amplification of a first carrier signal. The Raman amplifier module includes a pump having two optical sources, wherein the first optical source emits a linear beam along a first polarization axis of polarization, and the second optical source emits another linear beam along a second polarization axis distinct from the first axis. The two beams are combined to for the pumping signal. The Raman amplifier module also includes a polarization tuning means arranged to superimpose in real time at least one of the polarization axes to a Polarization Dependant Loss axis.

Abstract: A device for compensating the polarization dispersion suffered by an optical signal when it is transmitted by an optical line includes a polarization controller. It generates a differential time delay between two orthogonal polarization modes and controls the polarization controller so that it converts the signal transmitted by the line into a compensated optical signal. If the quality of the compensated optical signal remains below a reference quality the device modifies the state of polarization of the optical signal. Applications include long distance optical transmission via standard fibers.

Abstract: To increase the bit rate at which and the distance over which data can be transmitted by optical fiber, polarization dispersion is compensated by means of a polarization controller, a system for generating a differential group delay between two orthogonal modes of polarization and a control unit of the polarization controller. A chromatic dispersion compensator applies compensation which is adjusted dynamically to optimize the quality of the received optical signal. Applications include long-haul optical transmission on standard fibers.

Abstract: The invention relates to compensating chromatic dispersion and chromatic dispersion slope in optical fiber transmission systems. It proposes using dispersion compensating fiber (12) and a plurality of Bragg gratings (15, 16, 17) for compensating chromatic dispersion in the transmission fiber (4i). Each Bragg grating presents a bandwidth that is greater than 25 nm, so as to enable the system to be used in broad bands. In addition, the absolute value of the compensation provided by each Bragg grating is less than 250 ps/nm, thus ensuring that the grating remains easy to manufacture in spite of its broad band. The invention applies in particular to very high data rate systems (above 40 Gbit/s for each channel), with a utilization band extending between 1250 nm to 1650 nm.

Abstract: The present invention relates to an optical fiber transmission system in which at least a first carrier signal, having a wavelength in a first spectral band, is transmitted, said system including an optical fiber, at least a first Raman amplifier module for launching into said optical fiber a first pumping signal at an appropriate wavelength for a stimulated Raman amplification of said first carrier signal, said first Raman amplifier module including first pumping means comprising two optical sources, a first of said optical sources emitting at said appropriate wavelength a linear beam along a first axis of polarization, a second of said optical sources emitting at said appropriate wavelength a linear beam along a second axis of polarization distinct from said first axis, first combination means arranged to combine said beams in order to provide said first pumping signal.

Abstract: A device for compensating the polarization dispersion suffered by an optical signal when it is transmitted by an optical line includes a polarization controller. It generates a differential time delay between two orthogonal polarization modes and controls the polarization controller so that it converts the signal transmitted by the line into a compensated optical signal. If the quality of the compensated optical signal remains below a reference quality the device modifies the state of polarization of the optical signal. Applications include long distance optical transmission via standard fibers.

Abstract: The invention relates to a method of stabilizing managed optical solitons propagating in a dispersion-managed optical fiber transmission line, said method being characterized in that the following are performed periodically along the transmission line for each managed optical soliton: a first step consisting in establishing coupling that is substantially linear between the energy and the spectrum width of the optical soliton; and a second step consisting in setting the spectrum width by filtering, and, by means of the substantially linear coupling, in setting the energy of the soliton resulting from the first step, the center frequency of the filtering being substantially equal to the center frequency of the optical soliton.

Abstract: The invention enables wavelength division multiplexed (WDM) solitons conveyed by an optical fiber to be regenerated synchronously. The invention consists in using optical delay lines, in particular of the photorefractive filter type, prior to the regenerators so as to resynchronize a subset of the m soliton channels, and in placing the regenerator at a position where the n-m other soliton channels are naturally synchronized.

Abstract: Dispersion-shifted monomode optical fibers have an effective mode surface area greater than 65 .mu.m.sup.2 by optimization of the geometrical characteristics that characterize the fibers.

Abstract: Dispersion-shifted monomode optical fibers have an effective mode surface area greater than 65 .mu.m.sup.2 by optimization of the geometrical characteristics that characterize the fibers. The fibers have substantially zero chromatic dispersion in the vicinity of 1.55 .mu.m, and they include an optical core having a central portion, a first layer having an index lower than the index of the central portion, and a second layer having an index higher than the index of the first layer and higher than the index of the optical cladding.

Abstract: Light pulses carrying data in binary form to be transmitted are injected into a transoceanic line fiber in which they pass through amplifiers imparting Gordon-Haus jitter to them. In accordance with the invention, a compensation fiber is disposed at the output of the line fiber so as to apply negative chromatic dispersion to the pulses so as to compensate their jitter in part before they are processed in a receiver. The invention applies to telecommunications.

Abstract: An electrical power supply (20, 22) powers a semiconductor laser chip (2) under gain switching conditions so as to make the chip emit light pulses. The light pulses are compressed in a fiber (30) having negative dispersion, so that they constitute solitons. Their spectrum width is decreased by the fact that a gain segment powered by the power supply constitutes only a portion of the length of the resonant cavity of the chip. The invention applies to transmitting data over optical fibers.

Abstract: An optical communication link with correction of non-linear effects comprises an optical fiber transmission line subject to chromatic dispersion and non-linear effects and correction means for limiting the disadvantageous consequences of this dispersion and/or these non-linear effects. The correction means comprise at the output of the transmission line a dispersion compensator adapted to apply dispersion in the opposite direction to and of lower absolute value than the dispersion due to the transmission line.

Abstract: Dispersion-shifted monomode optical fibers have an effective mode surface area greater than 65 &mgr;m2 by optimization of the geometrical characteristics that characterize the fibers.