Route to Coherent Supercontinuum Generation in the Long Pulse Regime

In this paper, we investigate the possibility of generating supercontinuum in highly nonlinear fibers with improved stability characteristics through modulation of the input pulse. Specifically, we show that broadband coherent supercontinuum can be generated in the long pulse regime, provided the modulation parameters and nonlinear fiber length are carefully tuned. Based on physical arguments, we derive general guidelines for the choice of modulation frequency and fiber length. Significantly, the guidelines are valid for arbitrary long pulses.