Interplay of fiber nonlinearity and optical filtering in ultradense WDM

Reports an experimental study on the interplay between fiber nonlinearity and optical filtering in ultradense wavelength-division-multiplexing (UDWDM) transmission systems. It is found that fiber nonlinearity-induced spectral distortion of 10-Gb/s signals has a profound effect on the performance of optical demultiplexing filters, becoming especially pronounced as channel spacing approaches UDWDM dimensions of 25 GHz. The characteristics of the interaction between fiber nonlinearity and optical filtering are found to be different for self-phase modulation compared to cross-phase modulation limited systems.