LAUSR

Abstract. Nonlinear phase-drift on 16-QAM optical signals due to semiconductor optical amplifier gain saturation were measured for two devices—a linear and a nonlinear one—considering the input optical power and the net optical gain. The signal when amplified by the nonlinear device is marred even for low Pin (−20  dBm), and for moderate input powers (−15  dBm) signal quality stays always above the forward error correction (FEC) limit (error vector magnitude  =  16  %  ). The nonlinear device as expected induced more degradation, being able to operate fairly just for small gain and input power; for moderate gain (12 dB), the amplified signals stay always above the FEC limit. The linear device showed fair operation even for moderate Pin  =    −  15  dBm, working under FEC limit for OSNR (at Rx) higher than 16.5 dB for 10 Gbaud, and higher than 20 dB for 25 Gbaud, with small penalties (<2  dB) in relation to the back-to-back configuration.