Strong frequency conversion among light waves propagating in a low-birefringence optical fiber in the normal-dispersion regime is experimentally investigated. Modulational gain spectra are obtained by injection of a signal orthogonally polarized with respect to a pump beam aligned with the slow fiber axis. Measurements reveal that, for signal power levels above a certain threshold value, peak conversion is obtained at pump signal frequency detunings far from the phase-matching condition. The large-signal three-wave mixing regime is well described by integrable nonlinear coupled-wave equations.
© 1998 Optical Society of America
(190.0190) Nonlinear optics : Nonlinear optics
(190.4370) Nonlinear optics : Nonlinear optics, fibers
(190.4380) Nonlinear optics : Nonlinear optics, four-wave mixing
(190.4970) Nonlinear optics : Parametric oscillators and amplifiers
E. Seve, G. Millot, S. Trillo, and S. Wabnitz, "Large-signal enhanced frequency conversion in birefringent optical fibers: theory and experiments," J. Opt. Soc. Am. B 15, 2537-2551 (1998)