Origin of extrinsic chirality in metasurfaces and nanoholes fabricated by nanosphere lithography Emilija Petronijevic, Tiziana Cesca, Carlo Scian, Giovanni Mattei, Roberto Li Voti, Concita Sibilia and Alessandro Belardini EPJ Web Conf., 309 (2024) 06014 Published online: 31 October 2024 DOI: 10.1051/epjconf/202430906014