Effect of the CW-Seed's Linewidth on the Seeded Generation of Supercontinuum

We demonstrate numerically and experimentally the effect of the linewidth of the CW-seed on the seeded generation of supercontinuum. The qualitative simulation results, calculated from a numerical model based on the generalized nonlinear Schrödinger equation, show that the temporal coherence of the seeded supercontinuum benefits from a narrower linewidth of the CW-seed. In order to verify the numerical prediction, a CW-seed laser modulated by a phase modulator at different modulation frequencies is utilized to conduct the experimental analysis. With the increasing linewidth of the CW-seed, the contrast ratio of the interference fringe shows decreasing enhancement around the CW-seed and the corresponding four-wave mixing regions. Based on this, we employ four CW-seed lasers to enhance the temporal coherence of the seeded SC within the whole band.