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.