50Gbit/s PAM-4 MMF transmission using 1060nm VCSELs with reach beyond 200m. - Sriharsha Kota Pavan; Justin Lavrencik; Roman Shubochkin; Yi Sun; Jinkee Kim; Durgesh Vaidya; Robert Lingle; Tomofumi Kise; Stephen E. Ralph (OFC, 2014)