Crosstalk caused by nonideal output filters in WDM lightwave systems

Crosstalk mechanisms due to imperfections of the output demultiplexer in a 1550-mm wavelength-division multiplexed system are explored for the cable television frequency range of 50-800 MHz. Analytic and experimental results show significant crosstalk caused by the output demultiplexer: transmission slope following cross-phase modulation in the fiber, polarization-dependent loss following nonlinear polarization rotation in the fiber, and imperfect channel isolation. The crosstalk mechanism of transmission slope following cross-phase modulation is newly identified here.