Terabit Mode Division Multiplexing Discrete Multitone Signal Transmission Over OM2 Multimode Fiber

In this paper, we experimentally demonstrated Tb/s mode division multiplexed (MDM) transmission over 20m OM2 multimode fiber (MMF) using three linearly polarized modes, wavelength division multiplexing, intensity modulation and direct detection (IM-DD). The multi-plane light conversion (MPLC) based mode multiplexer/demultiplexer were adopted and its performance has been characterized. Three mode channels with the mode crosstalk less than -20 dB were selected to implement the MDM-MMF based transmission. Each mode channel was modulated by discrete Fourier transform spread discrete multi-tone (DFT-S DMT) scheme with 2048 subcarriers via 40 GHz Mach-Zehnder modulator (MZM). We obtained the error-free transmission of 135 Gb/s per mode per wavelength and total 1.62 Tb/s WDM-MDM below the forward error correction (FEC) limit of 3.8 × 10
^-3
at the received optical power (ROP) of > - 4.5 dBm with 86 GSa/s digital to analog converter (DAC). To the best of our knowledge, it is the highest bit rate per channel for the MDM based on conventional OM2 fiber transmission rather than the mode group division multiplexing (MGDM) based with cost-effective IM-DD and no multiple-in-multiple-out (MIMO) technology. The experimental results show that the MDM-MMF based transmission has the potential in the high-speed large-capacity short-reach optical interconnects.