Abstract: This antenna adaptor (840) is intended to be placed between an antenna (830) and a receiving channel (850). It includes: a first conductive wire (806) crossed by an external current (iext) corresponding to a signal delivered at the output of the antenna, the first wire generating in its vicinity an external magnetic field; and a magnetometric sensor (810), placed in the vicinity of the first conductive wire, sensitive to a flow of the external magnetic field and able to generate an output signal corresponding to the external current.

Abstract: This antenna adaptor (840) is intended to be placed between an antenna (830) and a receiving channel (850). It includes: a first conductive wire (806) crossed by an external current (iext) corresponding to a signal delivered at the output of the antenna, the first wire generating in its vicinity an external magnetic field; and a magnetometric sensor (810), placed in the vicinity of the first conductive wire, sensitive to a flow of the external magnetic field and able to generate an output signal corresponding to the external current.

Abstract: This current detection device (300) is characterized in that it includes: a first conductor wire (306) in which flows an external current (iext) to be measured, the first wire generating in its vicinity an external magnetic field (Bext); a magnetometric sensor (310) placed in the vicinity of the first conductor wire, sensitive to a flux of the external magnetic field and able to generate a measurement signal corresponding to the external current.

Abstract: This sensor (10) includes a magnetic sensor (12) generating a response signal (V) when it is immersed in an external magnetic field (Bext) generating an external flux (?ext) through said sensor. This sensor includes: a control circuit (14) taking as an input the response signal of the sensor and generating at the output a feedback current (iCR); and a conductive wire (16) positioned in the vicinity of the sensor and connected to the output of the control circuit, the wire being crossed by the feedback current, the circuit and the conductive wire being such that a feedback magnetic field (BCR) is generated, the flux of which through the sensor substantially compensates, at each instant, for the external flux, an output signal of the sensor being formed by the feedback current.

Abstract: A multichannel wavelength-division multiplex fiber optic transmission system includes an optical transmitter and an optical receiver connected by an optical line including at least one optical fiber and at least one set of channel regenerators. Successive regenerators regenerate respective groups of channels forming a subset of the set of channels.

Abstract: A method for remodulation of a modulated optical signal is disclosed which uses a disturbed line signal and an optical clock signal derived from the undisturbed original line signal modulated with the bitrate frequency feeding both signals in a Raman amplifying fiber connected to at least one Raman pump running the clock signal as Raman pump wavelength for the line signal.

Abstract: A synchronous optical regenerator applies intensity modulation and phase modulation. The phase modulation is effected after the intensity modulation by the crossed Kerr effect in a Kerr fiber. The clock used for the phase modulation is obtained by injecting a continuous wavelength into the intensity modulator. The regenerator therefore includes a multiplexer coupling continuous light with the signals transmitted, an intensity modulator modulating the signals transmitted and the continuous light, and a Kerr fiber phase modulating the transmitted signals by crossed phase modulation with the intensity-modulated continuous light. Applications include wavelength division multiplex transmission systems.

Abstract: The invention relates to wavelength division multiplex fiber optic transmission systems. It proposes a regenerator including a demultiplexer for separating the signals of various channels, a plurality of optical modulators each receiving signals from the demultiplexer and a modulation clock from a clock distribution unit, and a multiplexer combining the signals modulated by the modulators. The clock distribution unit includes a reference clock and, for each modulator, means for synchronizing the phase of a copy of the reference clock with the signals applied to the modulator. A phase-locked loop can be used for phase synchronization, with a phase shifter controlled in accordance with the average power of the signals at the output of the modulator. The invention enables only low-frequency components to be used to generate modulation clocks from a single reference clock.

Abstract: A messaging data management installation comprises i) messaging means (3, 5) able to receive messaging data in correspondence with user identifiers, ii) messaging data broadcast means (17-20), iii) at least one device (10) able to deliver a primary identifier representing a user identifier, iv) detection means (9-j) capable of detecting primary identifiers delivered by the device (10) and transmitting them, and v) management means (1, 8) capable, whenever they receive a primary identifier transmitted by the detection means (9-j), of determining the associated user identifier, and then seeking amongst the messaging data received by the messaging means (3, 5) those which are associated with the user identifier determined and, when such data are present, ordering their broadcast by at least one of the broadcast means (17-20).

Abstract: To delay optical signals precisely and continuously in a very small dynamic range, a device for applying a time-delay to optical signals includes a first phase modulator to receive an input optical signal carried by an original center wavelength and to apply a first stage of phase modulation to the carrier wave of the input signal to supply a first intermediate signal carried by a modified center wavelength, a delaying dispersive member having chromatic dispersion to receive the first intermediate signal and to supply a second intermediate signal, and a second phase modulator to receive the second intermediate signal and to apply a second stage of phase modulation to the carrier wave of the second intermediate signal to supply an output signal carried by the original center wavelength. Applications include optical telecommunication systems, in particular converting wavelength division multiplexed signals into time division multiplexed signals and regenerating wavelength division multiplexed signals.

Abstract: The invention concerns a fiber optic soliton signal transmission system comprising a signal amplifier means and signal regenerator means, in-line first filter means and second filter means associated with the regenerator means, the second filter means being different from the first filter means. Independent optimization of the in-line filter means and the filter means associated with the regenerator improves the performance of the transmission system. In the case of wavelength division multiplexed systems, the invention reduces the effects of jitter induced by collisions between solitons.

Abstract: A method for remodulation of a modulated optical signal is disclosed which uses a disturbed line signal and an optical clock signal derived from the undisturbed original line signal modulated with the bitrate frequency feeding both signals in a Raman amplifying fiber connected to at least one Raman pump running the clock signal as Raman pump wavelength for the line signal.

Abstract: A method of detecting one or more free channels in a time-division multiplexed optical signal which may be used for insertion signals in switching nodes of optical communication networks. The method includes sampling successive optical pulses from at least one of said channels, measuring the average optical power of the sampled pulses during a predetermined time period, and generating a detection signal if said average optical power is less than or equal to a predetermined threshold value.

Abstract: The invention concerns a fiber optic soliton signal transmission system comprising a signal amplifier means and signal regenerator means, in-line first filter means and second filter means associated with the regenerator means, the second filter means being different from the first filter means.

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: An optical fiber transmission system for soliton signals with wavelength multiplexing in which the bit times of the various channels &lgr;1 to &lgr;n of the multiplex are substantially synchronous, at least at one point. At least one saturable absorber is located at this point. The channels can be made synchronous by an appropriate selection of wavelengths, or by using optical delay lines, or the like. The saturable absorber then modulates the intensity of the soliton signals in the various channels of the multiplex. It is possible to use a clock for remotely driving the saturable absorber. The invention also relates to a corresponding transmission method. The invention makes it possible to transmit over long distances without using active components.

Abstract: A synchronous optical regenerator applies intensity modulation and phase modulation. The phase modulation is effected after the intensity modulation by the crossed Kerr effect in a Kerr fiber. The clock used for the phase modulation is obtained by injecting a continuous wavelength into the intensity modulator. The regenerator therefore includes a multiplexer coupling continuous light with the signals transmitted, an intensity modulator modulating the signals transmitted and the continuous light, and a Kerr fiber phase modulating the transmitted signals by crossed phase modulation with the intensity-modulated continuous light. Applications include wavelength division multiplex transmission systems.

Abstract: The invention relates to wavelength division multiplex fiber optic transmission systems. It proposes a regenerator including a demultiplexer for separating the signals of various channels, a plurality of optical modulators each receiving signals from the demultiplexer and a modulation clock from a clock distribution unit, and a multiplexer combining the signals modulated by the modulators. The clock distribution unit includes a reference clock and, for each modulator, means for synchronizing the phase of a copy of the reference clock with the signals applied to the modulator. A phase-locked loop can be used for phase synchronization, with a phase shifter controlled in accordance with the average power of the signals at the output of the modulator. The invention enables only low-frequency components to be used to generate modulation clocks from a single reference clock.

Abstract: To delay optical signals precisely and continuously in a very small dynamic range, a device for applying a time-delay to optical signals includes a first phase modulator to receive an input optical signal carried by an original center wavelength and to apply a first stage of phase modulation to the carrier wave of the input signal to supply a first intermediate signal carried by a modified center wavelength, a delaying dispersive member having chromatic dispersion to receive the first intermediate signal and to supply a second intermediate signal, and a second phase modulator to receive the second intermediate signal and to apply a second stage of phase modulation to the carrier wave of the second intermediate signal to supply an output signal carried by the original center wavelength. Applications include optical telecommunication systems, in particular converting wavelength division multiplexed signals into time division multiplexed signals and regenerating wavelength division multiplexed signals.

Abstract: The invention concerns a wavelength-division multiplex soliton signal fiber optic transmission system; to reduce the effects of collision jitter on the soliton channels, it proposes quasi-distributed amplification combining lumped amplification and distributed amplification. In this way it is possible to combine pumping of a lightly doped line fiber an dumped amplification by an EDFA in the repeaters. Reduncant and common pumping means are advantageously used for the lumped amplification and the distributed amplification and the gain of the lumped amplification is advantageously controlled automatically.