Bidirectional OFDM-WDM-PON system employing 16-QAM intensity modulated OFDM downstream and OOK modulated upstream

Abstract

We have investigated an orthogonal frequency-division multiplexing (OFDM) wavelength-division-multiplexing (WDM) passive optical network (PON) with centralized lightwave and direct detection. The system was demonstrated for both 10 Gbps 16 quadrature amplitude modulation (16-QAM) intensity-modulated OFDM downstream signals and 2.5 Gbps On-off keying (OOK) upstream signals respectively. A wavelength-reuse scheme is employed to carry the upstream data by using a mach-zehnder modulator (MZM) as an intensity Modulator at the optical network unit (ONU). The proposed scheme offers a promising solution for future PONs.