Proposed is an optical node that contains a number of A optical demultiplexers. Each demultiplexer is adapted to provide at its N output ports N incoming optical signals received from N optical cores of an incoming optical multi-core fiber. Furthermore, the optical node contains a number of B optical multiplexers. Each multiplexer is adapted to receive at its N input ports N outgoing optical signals and to insert the N outgoing optical signals into N optical cores of an outgoing multi-core fiber. The optical node is configurable to switch one of the incoming optical signals simultaneously onto B input ports of different multiplexers and to combine A of the incoming optical signals from A output ports of different demultiplexers onto a same input port of one of the multiplexers. Alternatively, N incoming signals are received from N different mode signals of a spatially multiplexed multi-mode fiber and then transmitted as N multi-mode signals into a spatially multiplexed multi-mode fiber.