Near-Infrared OAM Communication Using 3D-Printed Microscale Spiral Phase Plates. - Edgars Stegenburgs; Andrea Bertoncini; Abderrahmen Trichili; Mohd Sharizal Alias; Tien Khee Ng; Mohamed-Slim Alouini; Carlo Liberale; Boon S. Ooi (IEEE Commun. Mag., 2019)