Crosstalk penalty in all-optical distributed switching networks

We report both analytical and experimental results of the power penalty due to noncoherent crosstalk in multiwavelength all-optical networks that use space-division switching. Numerical analysis reveals that the power penalty is overestimated using a Gaussian approximation with <100 crosstalk signals or crosstalk levels >-20 dB. Numerical analysis shows a 1.8 dB power penalty for 6 crosstalk signals with each contributing -11.5 dB crosstalk while the Gaussian approximation predicts a power penalty /spl Gt/10 dB. We measure a power penalty of 1.7 dB for 3 crosstalk signals with each contributing -18 dB crosstalk. The numerical analysis agrees when the relative-intensity noise is taken into account.