Suppression of classical intensity fluctuations via competing nonlinear processes in an optical fiber

The noise-transformation properties of competing four-wave-mixing processes in an optical fiber are numerically investigated for an input signal with two frequency components, ${\mathrm{\omega }}_1$ and ${\mathrm{\omega }}_2$. When pulses from such a source propagate through a single-mode optical fiber, the two input frequency components can mix to form symmetric pairs of sidebands at ${\mathrm{\omega }}_3$=2${\mathrm{\omega }}_1$-${\mathrm{\omega }}_2$, ${\mathrm{\omega }}_4$=2${\mathrm{\omega }}_2$-${\mathrm{\omega }}_1$, ${\mathrm{\omega }}_5$=2${\mathrm{\omega }}_3$-${\mathrm{\omega }}_1$, and ${\mathrm{\omega }}_6$=2${\mathrm{\omega }}_4$-${\mathrm{\omega }}_2$. Noise that was initially confined to the input frequencies ${\mathrm{\omega }}_1$ and ${\mathrm{\omega }}_2$ is redistributed to the sidebands in a way that reduces the relative intensity fluctuations of the input frequencies, when the fiber length is judiciously chosen.