Generation of ultrashort vortex pulses by spiral array

•We put forward an approach for flexible selection of orbital-angular-momentum mode in the ultrashort laser pulse by an optical mask of the spiral array.•To our knowledge, this is the first time systematically and theoretically studying the formation of the ultrashort orbital-angular-momentum pulses by the optical mask diffraction.•We experimentally performed the function of the optical spiral array selecting the orbitalangular-momentum modes in ultrashort pulses, and the experimental results are highly consistent with the theoretical analyses.•The optical mask has the advantages of damage-resistance, without medium-dispersion, and ease of handling in ultrafast optics.•The spiral array is available to apply for the analysis and generation of other matter vortex beams within an axially scalar system. The ultrashort orbital angular momentum pulses, or the ultrashort optical vortex pulses, with the properties of the ultrashort duration and broadband spectrum, open significant applications in various contexts. The controllability of the orbital angular momentum in ultrashort vortex pulses crucially affects its capabilities. We put forward an approach for orbital angular momentum mode selection in an ultrashort laser pulse. This approach depends on an optical mask with multiple spirals rotationally and symmetrically arranged in a model of the spiral array. Both theoretical analyses and experimental work in the context of ultrashort vortex pulses demonstrate that the spiral array enables flexible generation of the structured orbital angular momentum modes. This optical mask shows the advantages of damage resistance, without medium-dispersion, and ease of handling in an ultrafast optical field. Furthermore, the spiral array can be applied to analyzing and generating other matter vortex beams within an axially scalar system.