Multiterabit Transmission over OM2 Multimode Fiber with Wavelength and Mode Group Multiplexing and Direct Detection

We demonstrate 5Tb/s bidirectional transmission (2.5Tb/s in each direction) over 2.2km of OM2 fiber using selective excitation of 4 mode groups, WDM multiplexing and direct detection. We use 20 wavelengths per mode group each wavelength is modulated using discrete multitone scheme with 1024 subcarriers using external Lithium Niobate Mach-Zehnder modulator (MZM). A minimum bit rate of 68.8Gb/s per channel is obtained for a Q2 factor of 8.5dB using a 65Gs/s digital to analog converter (DAC). We achieve same bit rate over 4.4km using 88Gs/ DAC. We also use electro-absorption modulated laser (EML) with a 3-dB bandwidth of 18GHz in the same mode group division transmission. We measured a 1dB power penalty with the EML compare to (MZM). We transmit a channel bit rate of 68.5Gb/ over 2.2km of OM2 fiber with the EML for the worst mode. Therefore, we demonstrate the transmission of the same throughput over multimode fiber using a low cost EML instead of external MZM.