Experimental verification of Gaussian approximation model of multiple intraband crosstalk in wavelength-division multiplexed networks using recirculating fiber loop

We experimentally investigate the validity of the Gaussian approximation model of intraband crosstalk from multiple channels, which can degrade system performance significantly in wavelength-division multiplexed (WDM) networks. A recirculating fiber loop is employed for the first time to generate multiple crosstalk elements up to 20. The power penalties predicted by the Gaussian approximation model match well with the experimental results as the number of crosstalk elements is increased. This is because the probability distribution of the signal power mixed with intraband crosstalk approaches the Gaussian distribution with growing number of crosstalk elements in accordance with the central limit theorem.