A system for measuring the duration, the temporal profile and the spectrum of an ultrashort laser pulse, the measurement system including a single-shot optical autocorrelator comprising: - a wavefront-splitting optical component (10, 11) arranged so as to receive a collimated wavefront of fundamental optical frequency (ω) coming from an ultrashort laser pulse source and to spatially split the collimated wavefront of an ultrashort light pulse into a first split wavefront propagating along a first direction and a second split wavefront propagating along a second direction forming a non-null angle with the first direction, the wavefront-splitting optical component including a Fresnel bi-prism or a Fresnel bi-mirror, - a non-linear optical crystal arranged at a determined distance from the wavefront-splitting optical component (10, 11) so that the first split wavefront and the second split wavefront are superimposed to each other in the non-linear optical crystal, - an optical system (22, 25, 26, 27, 28) forming an image of the non-linear optical crystal on a detection system (30, 50) spatially resolved in at least one direction, - a filtering device (21, 23, 24) arranged between the non-linear optical crystal and the detection system (30, 50), the filtering device (21, 23, 24) and the detection system being configured to detect simultaneously, on the one hand, a second-order single-shot interferometric or intensimetric autocorrelation trace at the double optical frequency (2ω) and, on the other hand, at least another single-shot autocorrelation trace of the first-order interferometric type at the fundamental optical frequency (ω), and in that - the measurement system includes a signal processing system configured to analyse, on the one hand, the second-order single-shot interferometric or intensimetric autocorrelation trace at the double optical frequency (2ω) and, on the other hand, the other single-shot autocorrelation trace at the fundamental optical frequency (ω), and to deduce therefrom a measurement of the duration, the temporal profile and the spectrum of an ultrashort laser pulse. - a wavefront-splitting optical component (10, 11) arranged so as to receive a collimated wavefront of fundamental optical frequency (ω) coming from an ultrashort laser pulse source and to spatially split the collimated wavefront of an ultrashort light pulse into a first split wavefront propagating along a first direction and a second split wavefront propagating along a second direction forming a non-null angle with the first direction, the wavefront-splitting optical component including a Fresnel bi-prism or a Fresnel bi-mirror, - a non-linear optical crystal arranged at a determined distance from the wavefront-splitting optical component (10, 11) so that the first split wavefront and the second split wavefront are superimposed to each other in the non-linear optical crystal, - an optical system (22, 25, 26, 27, 28) forming an image of the non-linear optical crystal on a detection system (30, 50) spatially resolved in at least one direction, - a filtering device (21, 23, 24) arranged between the non-linear optical crystal and the detection system (30, 50), the filtering device (21, 23, 24) and the detection system being configured to detect simultaneously, on the one hand, a second-order single-shot interferometric or intensimetric autocorrelation trace at the double optical frequency (2ω) and, on the other hand, at least another single-shot autocorrelation trace of the first-order interferometric type at the fundamental optical frequency (ω), and in that - the measurement system includes a signal processing system configured to analyse, on the one hand, the second-order single-shot interferometric or intensimetric autocorrelation trace at the double optical frequency (2ω) and, on the other hand, the other single-shot autocorrelation trace at the fundamental optical frequency (ω), and to deduce therefrom a measurement of the duration, the temporal profile and the spectrum of an ultrashort laser pulse.