SOA Intensity Noise Suppression: MulticanonicalMonte Carlo Simulator of Extremely Low BER

We present a thorough numerical study of intensity noise mitigation of spectrum sliced wavelength-division multiplexing (SS-WDM) systems employing a nonlinear semiconductor optical amplifier (SOA) before the modulator. Our simulator of the SS-WDM link, embedded inside a Multicanonical Monte Carlo (MMC) platform, estimates the tails of the probability density functions of the received signals down to probabilities smaller than 10^-6. We introduce a new, simple, and efficient technique to handle intersymbol interference (ISI) in MMC simulations. We address the impact of optical postfiltering on SOA noise suppression performance. While previous research experimentally observed the SOA-induced noise cleaning in SS-WDM systems, this is the first complete simulator able to correctly predict the ensuing BER improvement. We measure the BER at different bit-rates and validate predicted BERs with and without post filtering.