Experimental study of four-wave mixing on dispersion-shifted fiber and low dispersion fibers with a dense multiwavelength source

In wavelength-division multiplexed (WDM) systems four-wave mixing (FWM) can strongly affect the transmission performance on an optical link. The effect of FWM depends on the dispersion of the fiber and the characteristics of the WDM signals. The theory of the FWM effect has been much studied but experimental results do not always match very well with calculations. For this reason, experimental results on FWM are critical for multiwavelength system design. We report here the results of measurements of FWM in fibers having different zero-dispersion wavelength (λ₀), and for different WDM signal configurations, in order to quantify the effect of the different parameters (position of the zero-dispersion wavelength of the fiber, number, spacing, and power of the WDM channels). We also observed an unexpected and unexplained asymmetry of the FWM spectrum