Device for managing pulses in pump-probe spectroscopy

A device for managing light pulses for measuring the reaction of a sample exposed to a first light pulse, the measurement being performed by analysis of a signal emitted by the sample subjected to a second light pulse, shifted with respect to the first pulse by a determined interval of time, the device including two optical detectors for detecting the pulses of two light beams emitted by two pulsed laser sources, respectively, each beam emitting pulses with respective repetition frequencies that are different, arbitrary and stable over a determined period in the direction of the sample; the detectors being connected to a computer for determining the interval of time between two pulses coming from the first and the second beam, respectively, and constituting the first and second pulses; the computer being connected to an analyzer for measuring the reaction of the sample having as input parameter the interval of time between the two pulses, where the computer uses an algorithm making use of the stability of the repetition frequencies for determining the interval of time