We experimentally demonstrate a net-rate 503.61-Gbit/s discrete multitone
(DMT) transmission over 10-km 7-core fiber with 1.5-\mu m single mode VCSEL,
where low-complexity kernelrecursive-least-squares algorithm is employed for
nonlinear channel equalization.Comment: 3 pages, 44th European Conference on Optical Communication (ECOC
2018), Rome, Italy, 201