Abstract: The system includes processors each of which can drop an optical signal contained in one channel of an incoming optical multiplex signal and add an optical signal to the multiplex signal channel thereby made available. Each processor includes an optical signal drop filter and an optical signal add filter for an individual channel of particular wavelength, and these filters are connected by an optical switch. The drop filters and the add filters of the circuits of the system are connected in series, some in a drop subsystem and the others in an add subsystem, to transmit the multiplex signal from one filter to the other and from the drop subsystem to the add subsystem. They are distributed in order of decreasing drop or add wavelength from the input of the system at which the incoming multiplex signal is received.

Abstract: In packet time-division multiplexing communications systems using optical networks, an optical method and circuits used in electrical-to-optical conversion interfaces assure that data rates of the electrical domain match the data rates of the optical domain. An optical method of concatenating binary information contained in successive time windows of an input signal includes forming g converted input signals obtained by amplitude modulating g optical carrier waves having different wavelengths, each converted input signal presenting, within the time windows, amplitude modulation as a function of the input signal. The method also includes forming a multiplex signal made up of a combination of g delayed signals obtained by applying delays to the converted input signals, the delays being such that any two consecutive delayed signals are offset in time by the duration w of the time windows.

Abstract: In communications systems having optical networks, data rates in the electrical domain can be matched to data rates in the optical domain by means of time-division multiplexing, with the pulses forming the transmitted optical data being compressed. A method performs the necessary pulse decompression on reception in all-optical manner. The method includes forming q auxiliary signals respectively obtained by amplitude modulating each of q optical carrier waves having different wavelengths by the received signal, and superposing q delayed auxiliary signals obtained by applying delays to the auxiliary signals such that any two consecutive delayed auxiliary signals are offset in time by the duration of the pulses making up the received signal.

Abstract: In order to re-synchronize and shape a binary signal of bit time T0, a method includes forming a number p of sampled signals obtained by causing the signal to modulate pulses that are of frequency 1/T0 and of duration substantially equal to T0/p, and that are carried by p optical carriers having different wavelengths. The method also includes combining delayed signals that are obtained by applying delays to the sampled signals, such that any two consecutive delayed signals are offset in time by T0/p. The method applies to optical communications systems.

Abstract: Logic operations are carried out on binary optical signals using a non-linear optical amplifier having a front port and a rear port respectively receiving a front wave and a modulated rear wave. The output wave via the rear port is separated from the rear wave by exploiting the fact that they have opposite propagation directions. Applications include optical data switching and transmission.