Optimization of supercontinuum generation in highly nonlinear fiber for DFG based mid-infrared frequency comb

A theoretical investigation into the nonlinear propagation and dispersive wave generation in the anomalous dispersion region of the highly nonlinear fiber (HNLF) is present here. Owe to the non-linearity of dispersive wave and four-wave-mixing, by changing the parameter of input peak pulse, pulse width, initial chirp, and the parameter of HNLF, the optimum output in the short-wavelength region can be observed in the simulation results. It is found that the dispersive wave is mainly due to pulse trapping across the zero-dispersion wavelength (ZDW) by simulating the dispersive wave with different conditions. In the experiment, we can utilize the optimum parameter by the simulation to produce a high power pump source for difference frequency generation (DFG) method by 1550 nm near-infrared optical frequency comb. We have demonstrated a high pump power up to 12.5 mW coverage from 1025 to 1215 nm with a center wavelength of 1064 nm by choosing the HNLF with the dispersion of 4.933 ps/(nm. km) which is higher to the previous research. In our research, the simulation and experiment results are in good agreement in the article.