Record-high and robust capacity versus reach performance of adaptive real-time dual-band optical OFDM signals for upgrading legacy MMF systems

Real-time dual-band optical orthogonal frequency division multiplexing (OOFDM) transceivers incorporating DACs/ADCs operating at sampling speeds as low as 4GS/s and FPGA-based DSP clocked at only 100MHz are employed to explore the maximum achievable transmission performance of electro-absorption modulated laser-based multimode fiber (MMF) systems subject to conventional optical launching. Making use of adaptive subcarrier bit and subcarrier/sub-band power loading, record-high 20.125Gb/s over 800m OM2 MMF transmission of real-time dual-band OOFDM signals is experimentally demonstrated, for the first time, with an optical power penalty as low as 1dB. In addition, extensive experimental explorations of dual-band OOFDM capacity versus reach performance are also undertaken over the aforementioned systems consisting of different MMF types and lengths. It is shown that 20.125Gb/s over 100m and 19.625Gb/s over 1000m OOFDM transmissions are obtainable in OM2-only MMF systems, and that 20Gb/s over 100m and 19.375Gb/s over 1000m OOFDM transmissions are achievable in OM1-only MMF systems. Furthermore, in various OM1 and OM2 MMF systems, minimum optical power penalties of <;1dB are observed for MMF transmission distances ranging from 300m to 800m. Experimental results indicate that >19Gb/s over 1000m transmission of dual-band OOFDM signals are practically feasible in any legacy MMF systems.