Optical control ofχ3-frequency conversion by the second-order modulation instability

A numerical study showing the excitation and control of second-order modulation instability (MI) dynamics in nonlinear optical fibers via two optical seed fields located under the MI gain spectrum is presented. The phase dependence of the two weak input seed fields on the temporal and spectral second-order MI dynamics, i.e., on the frequency generation process, is investigated. The considered approach allows the generation and control of asymmetric MI spectra, modifiable via the phase relation of the initial seed fields with considerably small amplitudes. An optimal frequency relation of the seed fields for the highest possible influence could be identified. Furthermore, the phase-dependent effect of second-order MI is discussed for a pulsed excitation and higher-order perturbative effects, such as higher-order dispersion, Raman scattering, and self-steepening.