Method for characterization of a light beam comprising one or more ultrashort laser pulses having space-time couplings comprising the following steps: - separation of the light beam by means of a separator optic (Os, SR) into a first sub-beam and a second sub-beam, the first sub-beam taking a first optical path and the second sub-beam taking a second optical path; - propagation of the first sub-beam over a first optic and of the second sub-beam over a second optic, the first optic having a first radius of curvature so that the first sub-beam on leaving the first optic, referred to as "reference beam" (Fref), has wave fronts of a first type, the second optic having a second radius of curvature different from the first radius of curvature so that the second sub-beam on leaving the second optic, referred to as "characterized beam" (Fcar), has wave fronts of a second type different to the first type, the first sub-beam having an inhomogeneous electromagnetic field over the entire surface of the first optic, said first and second optics (O1, O2) being, thanks to control means (Pz), respectively arranged in the first and second optical paths (C1, C2) so that the reference beam (Fref) and the characterized beam (Fcar) are separated by a time delay τ sweeping a time interval T1 with a step P1; - recombination of the reference beam (Fref) and the characterized beam (Fcar) by means of a recombiner optic (Or, SR) in such a way that the beams spatially interfere and form a two-dimensional interference pattern, the pattern extending along a first plane; - measurement of said two-dimensional interference pattern by means of a measurement system as a function of the time delay τ sweeping the time interval T1 with the step P1 between the reference beam (Fref) and the characterized beam (Fcar), in order to obtain a temporal interferogram; - calculation, by means of a calculator, of the Fourier transform in the frequency domain of at least one spatial point of the temporal interferogram, said Fourier transform in the frequency domain having a frequency central peak (fc) and first and second frequency side peaks (fl1, fl2); - calculation, by means of a calculator, of the spectral amplitude A R (ω), referred to as "relative spectral amplitude", and of the spatial-spectral phase φ R (x,y,ω), referred to as "relative spatial-spectral phase", for one of said first and second frequency side peaks of said Fourier transform in the frequency domain. - separation of the light beam by means of a separator optic (Os, SR) into a first sub-beam and a second sub-beam, the first sub-beam taking a first optical path and the second sub-beam taking a second optical path; - propagation of the first sub-beam over a first optic and of the second sub-beam over a second optic, the first optic having a first radius of curvature so that the first sub-beam on leaving the first optic, referred to as "reference beam" (Fref), has wave fronts of a first type, the second optic having a second radius of curvature different from the first radius of curvature so that the second sub-beam on leaving the second optic, referred to as "characterized beam" (Fcar), has wave fronts of a second type different to the first type, the first sub-beam having an inhomogeneous electromagnetic field over the entire surface of the first optic, said first and second optics (O1, O2) being, thanks to control means (Pz), respectively arranged in the first and second optical paths (C1, C2) so that the reference beam (Fref) and the characterized beam (Fcar) are separated by a time delay τ sweeping a time interval T1 with a step P1; - recombination of the reference beam (Fref) and the characterized beam (Fcar) by means of a recombiner optic (Or, SR) in such a way that the beams spatially interfere and form a two-dimensional interference pattern, the pattern extending along a first plane; - measurement of said two-dimensional interference pattern by means of a measurement system as a function of the time delay τ sweeping the time interval T1 with the step P1 between the reference beam (Fref) and the characterized beam (Fcar), in order to obtain a temporal interferogram; - calculation, by means of a calculator, of the Fourier transform in the frequency domain of at least one spatial point of the temporal interferogram, said Fourier transform in the frequency domain having a frequency central peak (fc) and first and second frequency side peaks (fl1, fl2); - calculation, by means of a calculator, of the spectral amplitude A R (ω), referred to as "relative spectral amplitude", and of the spatial-spectral phase φ R (x,y,ω), referred to as "relative spatial-spectral phase", for one of said first and second frequency side peaks of said Fourier transform in the frequency domain.