First experimental demonstrations of real-time optical OFDMA PONs with adaptive dynamic bandwidth allocation and colorless ONUs

End-to-end real-time optical orthogonal frequency division multiple access (OOFDMA) passive optical networks (PONs) with adaptive dynamic bandwidth allocation (DBA) and colorless optical network units (ONUs) are experimentally demonstrated, for the first time, at aggregated 10.375Gb/s over 26.4km standard single mode fibers (SSMFs) based on intensity-modulation and direct-detection. The colorless ONU operation across the entire C-band is successfully achieved by utilizing cost-effective reflective semiconductor optical amplifier (RSOA) intensity modulators, whose narrow signal modulation bandwidths are fully exploited through adaptability of the OOFDM transceivers and adaptive DBA. Taking into account the optical beat interference effect, the impact of wavelength spacing between adjacent ONUs on the upstream OOFDMA PON performance is experimentally investigated, based on which the minimum achievable ONU wavelength spacing is identified.