3×4×10-Gb/s MDM-WDM Transmission over 21-km OM3 MMF with OOK Modulation and Direct Detection

3×4×10-Gb/s IM-DD MDM-WDM transmission over OM3 MMF is experimentally demonstrated. 3 modes with large Δneff are selectively excited as independent-spatial-channels. Enabled by cascaded low-modal-crosstalk MSCs and wavelength-interleaved scheme, a record distance of 21-km is achieved.