Experimental verification of a new model describing the influence of incomplete signal extinction ratio on the sensitivity degradation due to multiple interferometric crosstalk

Larger optical penalties than predicted by a Gaussian crosstalk model are found both in our experiments and in the literature when investigating signals including multiple interferometric crosstalk contributions. We attribute this to an imperfect signal extinction ratio. In this letter, simple analytical relations for crosstalk induced power penalties are derived taking the signal extinction ratio into account and excellent agreement with 10-Gb/s experiments is obtained. Both theory and experiments show the importance of the signal extinction ratio in connection with interferometric crosstalk.