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, ω₁ and ω₂. 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 ω₃=2ω₁-ω₂, ω₄=2ω₂-ω₁, ω₅=2ω₃-ω₁, and ω₆=2ω₄-ω₂. Noise that was initially confined to the input frequencies ω₁ and ω₂ 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.