Orbital-angular-momentum mode (de)multiplexer: A single optical element for MIMO-based and non-MIMO-based multimode fiber systems. - Milione, Giovanni; Huang, Hao; Lavery, Martin P. J.; Nguyen, Thien An; Xie, Guodong; Cao, Yinwen; Willner, Moshe; Tur, Moshe; Dolinar, Sam; Alfano, Robert R.; Padgett, Miles J.; Willner, Alan E. (2014)