A non-linear optical system for generating or amplifying light pulses (60, 61) by N-wave mixing, including a non-linear optical medium adapted to receive at least one first light pulse (51, 53) and one second light pulse (52, 522) having respective durations of the same order of magnitude, characterized in that the non-linear optical system for generating or amplifying light pulses includes: - a source adapted to generate a source pulse light signal, - an optical beam splitter configured to separate the source pulse light signal and form a first source signal and a second source signal, - a first optical amplifier arranged to receive the first source signal and form the first light pulse and a second optical amplifier arranged to receive the second source signal and form the second light pulse, the first optical amplifier and the second optical amplifier being arranged in parallel channels, the non-linear optical medium being arranged to receive the first source signal at the output of the first optical amplifier and respectively the second source signal at the output of the second optical amplifier, - a modulation device including a variable optical delay line arranged in the optical path of the second source signal, to modulate a time delay between the second light pulse and the first light pulse in the non-linear optical medium, the time delay modulation device being arranged upstream from the non-linear optical medium, and the modulation device (40, 41, 42) being adapted to switch the time delay between a first null delay value and, respectively, a second non-null delay value, so as to desynchronise the second light pulse relatively to the first light pulse in the non-linear optical medium, the variable optical delay line comprising an acousto-optic or electro-optic modulator adapted to switch the second source signal either towards a first optical path, having a first optical delay value associated with the first time delay value, or towards a second optical path, having a second optical delay value associated with the second time delay value, so as to modulate the generation or the amplification of a light pulse by N-wave mixing of said at least one first light pulse and one second light pulse in the non-linear optical medium. - a source adapted to generate a source pulse light signal, - an optical beam splitter configured to separate the source pulse light signal and form a first source signal and a second source signal, - a first optical amplifier arranged to receive the first source signal and form the first light pulse and a second optical amplifier arranged to receive the second source signal and form the second light pulse, the first optical amplifier and the second optical amplifier being arranged in parallel channels, the non-linear optical medium being arranged to receive the first source signal at the output of the first optical amplifier and respectively the second source signal at the output of the second optical amplifier, - a modulation device including a variable optical delay line arranged in the optical path of the second source signal, to modulate a time delay between the second light pulse and the first light pulse in the non-linear optical medium, the time delay modulation device being arranged upstream from the non-linear optical medium, and the modulation device (40, 41, 42) being adapted to switch the time delay between a first null delay value and, respectively, a second non-null delay value, so as to desynchronise the second light pulse relatively to the first light pulse in the non-linear optical medium, the variable optical delay line comprising an acousto-optic or electro-optic modulator adapted to switch the second source signal either towards a first optical path, having a first optical delay value associated with the first time delay value, or towards a second optical path, having a second optical delay value associated with the second time delay value, so as to modulate the generation or the amplification of a light pulse by N-wave mixing of said at least one first light pulse and one second light pulse in the non-linear optical medium.