Paraxial and non-paraxial optical skyrmionsJörg Götte, Zhujun Ye, Amy McWilliams, Claire Cisowski, Fiona Speirits, Sonja Franke-Arnold and Stephen M. BarnettEPJ Web Conf., 309 (2024) 11003DOI: https://doi.org/10.1051/epjconf/202430911003