10 Gb/s long-reach PON system based on directly modulated transmitters and simple polarization independent coherent receiver

We demonstrate a coherent 10 Gb/s PON system solution exploiting a direct modulated laser (DML) transmitter to obtain long reach (>100 km). The system exploits a simplified coherent receiver. This receiver, which is similar to the scheme that we recently proposed, had to be adapted to obtain polarization-independent operation with a chirped signal from a DML and is still based on simple optical and electrical components. Thanks to the combined use of coherent-RX and DML, the system achieves a link budget of 43 dB for 105 km transmission distance with no need of dispersion compensation. This makes it a cost-effective, simple, and robust solution for satisfying the increasing capacity request of access networks.