Numerical investigation on coherent mid-infrared supercontinuum generation in chalcogenide PCFs with near-zero flattened all-normal dispersion profiles

We design a novel all-normal flat near-zero dispersion chalcogenide photonic crystal fiber (PCF) for generating mid-infrared (MIR) supercontinuum (SC). The proposed PCF with a core made of As₂Se₃ glass and uniform air holes in the cladding is selectively filled with As₂S₅ glass. By carefully engineering the PCF with an all-normal flat near-zero dispersion profile, the anomalous-dispersion soliton effect is reduced, thus enabling broadband highly coherent SC to be generated. We also investigate the influence of the pulse parameters on the SC generation. Broadband SC covering 1.4 μm-10 μm with perfect coherence is achieved by pumping the proposed 3-cm-long PCF with 3-μm 100-fs pulses. The results provide a potential all-fiber realization of the broadband coherent MIR-SC.