10Â Gbit/s mode-multiplexed QPSK transmission using MDM-to-MFDM based single coherent receiver for intra- and inter data center networking

Generalized few-mode-fiber (FMF) transmission uses N coherent receivers for mode detection, where N scales with the number of fiber modes. Multiple coherent receivers increase the cost of optical network units (ONUs) in access networks, specifically for intra- and inter data center applications. We have experimentally evaluated a cost effective low-complexity receiver architecture based on mode-division multiplexing (MDM) to mode frequency-division multiplexing (MFDM) conversion for data center connectivity. A single coherent receiver is used to efficiently detect 10 Gbit/s QPSK Nyquist signals over 2.8 km 4-LP mode graded index fiber reducing the ONUs complexity to N/4. All the transmitted modes are successfully detected below the forward-error-correction (FEC) limit, i.e. 1×10−3 BER.