Extended Data Fig. 3: Chirality and number of intertwined helices obtained from the analytical theory.
From: Broadband control of topological–spectral correlations in space–time beams
δℓ is a parameter in our analytical theory of helical wave packets with linear topological-spectral correlations corresponding to the discrete step in OAM value between two neighboring spectral windows. Cylinders represent the 2D space defined by the azimuthal angle and time variable, and on their surfaces we plot the intensity of the wave packet from equation S12 of Supplementary Note 7. a,b, By changing the sign of δℓ, the chirality of the helical wave packet changes. b–d By increasing the magnitude of δℓ, the number of intertwined helices increases correspondingly.
