Multi-beam vortex generation induced by the non-linear optical anisotropy of grapheneLuis Plaja, Ana García-Cabrera, Roberto Boyero-García, Óscar Zurrón, Julio San Román and Carlos Hernández-GarcíaEPJ Web Conf., 266 (2022) 08012DOI: https://doi.org/10.1051/epjconf/202226608012