OFDM/WDM PON with laserless, colorless 1 Gb/s ONUs based on Si-PIC and slow IC

We introduce a next-generation long-reach access optical network (35 dB loss budget +2 dB margin) delivering up to 40G/40G per passive 1:256 optical distribution network, supporting symmetrical 1 Gb/s rates per home user or up to 40 Gb/s for business users (e.g., enterprises, antenna sites). The proposed system is based on a novel spectrally efficient orthogonal frequency division multiplexing/wavelength division multiplexing OFDM/WDM architecture symmetrically using 16-QAM OFDM polarization diversity in both the downstream and upstream in order to serve low-cost energy-efficient symmetric 1 Gb/s optical network units (ONUs), which are self-coherent, laserless, colorless, and tunable-filter-free. Each ONU comprises a standard semiconductor optical amplifier (SOA), a silicon-based photonic integrated circuit (PIC), and mixed-signal electronic integrated circuits (ICs) performing the signal processing at a relatively slow rate as compared with the overall passive optical network (PON) throughput: digital to analog converters (DACs) and analog to digital converters (ADCs) at 417 MS/s for the home user ONUs.