Performance comparison of Bragg grating-based optical add-drop multiplexers in WDM transmission systems

The filtering performance of Bragg grating-based optical add-drop multiplexers (OADMs) is studied using theoretical system simulations. The implications of the non-optimum spectral characteristics of the coupler-based OADM are quantified and compared with other filter configurations. Simulation of the performance of a non-fully optimised add/drop filter of this type, in an intensity modulation/direct detection communication system at 40 Gbit/s transmission speed, where filter/laser source misalignments and cascading operations are present, suggests an excessive eye-opening penalty of at least 0.15 dB compared to the case where fully optimised, spectrally flat filters, are deployed