Finite-band noise theory and experiment for four-wave mixing in RZ transmission systems

The finite-band noise theory of four wave mixing (FWM) is introduced. It was validated using simulations and experiments. It predicts FWM noise scaling with bit alignment among channels and enables comparisons between RZ and NRZ modulation formats. We introduced a general finite-band technique for calculating the contribution of FWM to Q and validated it using both numerical simulations and laboratory experiments. This theory shows that the level of FWM noise or cross talk decreases as the bit slots are shifted and that the FWM Q for RZ formatted data tends to be larger than that in systems with NRZ modulation.