Raman cascade suppression by using wide band parametric conversion in large normal dispersion regime.

We present experimental results on the suppression of a complete Raman cascade in a holey fiber by using gain competition with parametric processes. The modulation instabilities which strongly affect the stimulated Raman scattering (SRS) gain are induced by two pump wavelengths (532 nm, 1064 nm) placed far and quasi symmetrically on each side of the zero dispersion wavelength (ZDW) of the fiber (790 nm). The competition between these two nonlinear effects takes place in large normal dispersion regime. We experimentally determinate the quantity of energy needed at each pump wavelength to obtain total suppression of the SRS and we evaluate the sensitivity of this effect with respect to the ZDW position.