Experimental Characterization of Nonlinear Distortions of Semiconductor Optical Amplifiers in the WDM regime

This paper presents an experimental characterization of the impact of nonlinear impairments induced by semiconductor optical amplifiers (SOA) in a wavelength division multiplexed (WDM) coherent communication system. Motivated by a ceaseless traffic growth in optical transport systems, extending the bandwidth of a fiber link is a promising way to increase the throughput in optical networks. Using specific design, SOA can provide ultra-wideband (UWB) and continuous amplification spreading from S to L bands. For both off-the-shelf C-band SOA and UWB SOA devices, we show that SOA nonlinear impairments are not critical in the WDM regime. We report on the impact of the WDM channel count on the nonlinear distortions induced by an UWB SOA. We also demonstrate that besides having a wider bandwidth, our custom UWB SOA devices have superior performance compared to off-the shelf components even for C-band only transmission; and are well suited for wideband WDM signal amplification.