Ultra-High Capacity Optical Satellite Communication System Using PDM-256-QAM and Optical Angular Momentum Beams. - Shippu Sachdeva; Simarpreet Kaur; Romisha Arora; Manoj Sindhwani; Krishan Arora; Woong Cho; Gyanendra Prasad Joshi; Ill Chul Doo (Sensors, 2023)