Transmission Challenges of Cascaded Semiconductor Optical Amplifiers

The semiconductor optical amplifier (SOA) is a proper component for simultaneous modulation and amplification what is a good approach for sub-carrier multiplexed optical signal transmission. However, cascading several SOAs a new problem arises, an increase in the distortion due to cross-modulation of the different channels. In the paper an optimum approach is presented to overcome that distortion problem.