Abstract: The device comprises a first opto-optical gate for resynchronization and a second opto-optical gate for amplitude regeneration, the signal output by the first gate being applied to the control input of the second gate. The device also includes an opto-optical gate for regenerating contrast which receives a signal to be generated both on a source input and on a control input. The opto-optical gate is a three-input Mach-Zehnder interferometer, with each of the two branches thereof having a respective semiconductor optical amplifier.

Abstract: The invention relates to a wavelength conversion apparatus for transmitting data carried by an incident pump wave beam of wavelength .lambda. to a probe wave of wavelength .lambda..sub.s. The apparatus has two semiconductor optical amplifiers and means for splitting the incident pump wave beam so as to inject a respective secondary pump wave beam into each of said optical amplifiers, said optical amplifiers are connected in series on the path of the probe wave so that each of them modulates said wave in intensity with the corresponding secondary pump wave beam by means of a crossover gain-saturation phenomenon.