Impact of the modulation instability on supercontinuum generation

We discuss the combination of soliton fission, induced by third-order dispersion, and modulation instability. Furthermore, we investigate the impact of fourth-order dispersion on the modulation instability in the case of normal dispersion. The overall observed behavior of SC generation turns out to be primarily determined by the modulation instability. Because higher-order effects are not a prerequisite for the generation of supercontinuum, it is not restricted only to ultrashort sub-picosecond pulses, hut appears for much longer pulses too. It can also appear in the normal dispersion regime β₂ > 0, if the fourth-order dispersion coefficient β₄ is negative.