Simple Uplink SOA Pattern Effects Compensation for Reach-Extended 10G-EPONs

A simple and effective technique enabling strong pattern effects mitigation in uplink in-line semiconductor optical amplifiers (SOAs) for reach-extended, high-speed, passive optical networks, is proposed and experimentally demonstrated. The technique relies in selectively injecting into the saturated amplifier a low-power CW assist light (AL) at shorter wavelength than the data signal. The presence of the AL, which is enabled when the power level of input data triggers pattern effects in the SOA, clamps the carrier density with almost negligible gain reduction at the 1.3 μm data wavelength. By injection of an AL signal at 1.27 μm with 1 mW power in the booster SOA of a two-SOA cascade reach-extender, an increase as large as 7 dB in the access span loss dynamic range for error-free transmission at 10 Gb/s is reported with a trunk span loss of 23 dB.