Fig. 4: Poynting vector fields of toroidal and supertoroidal light pulses.
From: Supertoroidal light pulses as electromagnetic skyrmions propagating in free space
a, b Contour and arrow plots of the Poynting vector fields in the x–z plane, in logarithmic scale, for a) the fundamental TLP and b the STLP of α = 5. Panels a1 and b1 present the zoom-in plots of the regions of blue boxes in (a) and (b), respectively. Poynting vector field zeros are marked by the black solid lines and black dots. Red and blue bold arrows highlight the regions of energy forward flow and backflow, respectively. Unit for coordinates: q1.
