Dense SS-WDM Over Legacy PONs: Smooth Upgrade of Existing FTTH Networks

We propose a hybrid passive optical network (PON) architecture supporting time-division multiplexing (TDM) and dense spectrum-sliced wavelength-division multiplexing (SS-WDM) over the legacy PON infrastructure. We use a fiber Bragg grating (FBG)-based self-seeded reflective semiconductor optical amplifier (RSOA) transmitter in conjunction with a recently proposed balanced receiver (BR); identical transceiver pairs are placed at the central office and customer side. Self-seeded RSOAs obviate the need for centralized sources, providing a high power, directly modulated source. Intensity noise mitigation of this thermal source is investigated by operating the RSOA in saturation and employing the recently proposed BR. We study the optimal reflectivity for seeding that balances signal power and noise cleaning to achieve the best bit error rate (BER) possible; channel widths are comparable with dense WDM when using coherent sources.