An embodiment relates to a device for generating a short duration laser pulse, which comprises: means for generating a laser beam and for filtering same, arranged in such a way as to generate an input laser beam providing an input laser pulse; a transparent slide comprising a non-linear scattering material; the laser generation means being arranged so that the slide widens the spectrum of the input laser pulse by phase self-modulation in order to generate a wide-spectrum laser pulse; compression means adapted for compressing the wide-spectrum laser pulse in order to generate a short duration laser pulse; wherein the laser generation means are arranged so that the input beam is spatially uniform on the transparent slide and has a break integral B lower than three when the input beam passes through the transparent slide.