Demonstration of a 15-Mode Network Node Supported by a Field-Deployed 15-Mode Fiber

This paper extends a recent demonstration of a 2-line side 15-mode spatial division multiplexing network node. The node is based on fifteen 2 × 2 wavelength cross-connects (WXCs) to direct up to six 5 Tb/s, 15-mode, spatial super channels (SSCs). For this demonstration, we consider full add and drop, full express and partial add and drop network scenarios. The WXCs were made using three commercial 4 × 16 wavelength cross-connects, which were reprogrammed to each implement five identical 2 × 2 WXCs. The network node is demonstrated using a 6.1 km, 15-mode, multi-mode fiber (MMF) with a standard cladding diameter of 125 μm. This is the first field-deployed MMF and is installed in an underground tunnel in the city of L'Aquila, Italy. We further extend the network node to support up to 20 SSCs for a throughput per line side of 100 Tb/s. It is shown that the MIMO requirements for this type of systems is strongly dependent on the differential delays of the different modes propagating within the network node.