10 Gb/s Bidirectional Transmission with an Optimized SOA and a SOA-EAM Based ONU

We investigated the application of a semiconductor optical amplifier (SOA) and an SOA electro-absorption modulator (SOA-EAM) as attractive, low-cost solutions in passive optical networks (PONs). The main characteristics of an SOA with optimal performance for phase and amplitude modulation were tested. Additionally, a 10 Gb/s bidirectional transmission with an optical network unit (ONU) transmitter integrated with a distributed feedback (DFB) laser, electro-absorption modulator (EAM), and SOA was designed. The upstream (US) and downstream (DS) receiver sensitivities at the forward error correction (FEC) level reached −29.5 dBm and −33.5 dBm for back-to-back (BtB) fiber and −28.9 dBm and −33.1 dBm for 20 km fiber. For multichannel transmission, the US receiver sensitivities reached −28.8 dBm and −28.2 dBm for BtB and 20 km fibers, and the DS receiver sensitivities reached −33 dBm and −32.6 dBm for BtB and 20 km fibers, respectively.