Crosstalk due to optical fiber nonlinearity in WDM CATV lightwave systems

Cross talk in a two-wavelength 1550-nm system at subcarrier frequencies 50 MHz to 800 MHz is investigated. Its dependence on subcarrier frequency, wavelength spacing, and optical power is measured. At wavelength spacings >4 nm, gain from stimulated Raman scattering accounts for most of the cross talk.