400G Coherent and IMDD Transmission over 50 mu m Core Multimode Fiber Links with Multiple Connector Junctions Using LP01 Mode-Matching Adapters

We studied the fundamental mode transmission over 50.m core OM2 multimode fiber with up to six connector junctions or seven spans enabled by LP01 mode matching adapters using 400G coherent and IMDD transceivers, i.e., 400G ZR and LR4 transceivers. The connector offset distribution of commercially available OM2 cables was measured and analyzed. The link level performance as dictated by multi-path interference and transfer functions was studied. Successful transmission over multiple spans formed by 20 m cables and a 200 m cable was demonstrated. It is found that the connector quality from commercial cables can support up to 2 connector pairs for 400G LR4 transmission and at least 6 connector pairs for 400G ZR transmission with the use of specially designed mode matching adapters. 400G LR4 transmission performance is significantly worse using standard single-mode fiber jumpers instead of the special mode adapters, but 400G ZR transmission worked well with both approaches.