25 Gbps MMF Link Transmission Studies: Experiments and Modeling

摘要

We experimentally demonstrate a reach of up to 150 m for 25 Gbps OM4 MMF-based links with a multi-moded VCSEL using a PRBS31 pattern. This reach is established even for an OM4 fiber with bandwidth closer to specification limit. While the IEEE spreadsheet model indicates mode partition noise (MPN) to be the limiting impairment in 25 Gbps links, the measured bit error rate (BER) curves apparently do not show evidence of MPN. Using end-to-end link simulations that process PRBS sequences and incorporate a more accurate mode partition noise model than the IEEE spreadsheet, we substantiate the above experimental observations. However, numerical modeling indicates the presence of MPN effects and further suggests that the MPN parameter k_(MPN) may need to be lowered from the currently accepted value of 0.3 to the 0.1-0.2 range.