Abstract: Adjusting power for a WDM optical transmission system comprising emitter means, an optical transmission line, and receiver means, the method being characterized in that for each wavelength channel, the power emitted for said channel by the emitter means is adjusted as a function of the optical powers received for said channel at a plurality of points distributed along the transmission line.

Abstract: An optical fiber transmission system using RZ pulses and having emitter means, receiver means, and a transmission line which extends between said emitter means and receiver means, the emitter and receiver means implementing wavelength division multiplexing, the transmission line comprising a plurality of main optical fiber sections presenting dispersion of a given type with dispersion-compensating means being interposed therebetween, the system being characterized in that the dispersion compensation implemented by said means is such that the spectrum width of pulses at the outlet from said means is constant over the length of the transmission line.

Abstract: The invention provides a method of positioning an electrical control signal (S1, S1bis) for an electro-optical modulator (5) relative to the characteristic (VA, VB) of the modulator (5), in which method a disturbing signal (S2, S2bis) is superposed on the control signal (S1, S1bis) and the position of the control signal (S1, S1bis) is adjusted as a function of the value of a component in the output signal of the modulator (5) corresponding to the applied disturbance (S2, S2bis), in which method the disturbance (S2, S2bis) is superposed on the control signal (S1, S1bis) when the control signal takes a value (VA) that ought to correspond to a minimum slope point (A) of the characteristic, and the positioning of the control signal (S1, S1bis) is adjusted in such a manner as to minimize the amplitude of the disturbance as output due to said disturbance of the control signal (S1, S1bis), the method being characterized in that the characteristic of the modulator (5) includes a second minimum slope point (B) corresp