Fig. 3: Transition of topological state in 2D optical skyrmions.
From: Topological state and number transitions of optical skyrmions upon free-space beam propagation
a Simulated longitudinal intensity distribution of 2D optical skyrmions within the range of z = 0–30 cm. b The experimental intensity, polarization, topological state and skyrmion number of 2D optical skyrmions at different longitudinal positions z = 7.5 cm, z = 15 cm, z = 22.5 cm; Purple dashed circle: The integration range of skyrmion density. c Simulated (green spherical dotted line plot) and experimental results (magenta square dotted line plot) of the skyrmion number varying with propagation distance.
