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We experimentally demonstrate that a variable longitudinal dispersion profile can enhance supercontinuum generation in a chalcogenide tapered fiber, compared to tapered fibers with a standard, constant dispersion profile. For this purpose, nonlinear As 2 S 3 tapered fibers are compared experimentally and numerically based on their dispersion profile. The optimal taper with non-uniform dispersion profile simultaneously enhances the energy transfer to both dispersive waves and Raman solitons towards shorter and longer wavelengths, respectively. The generated supercontinuum spans within the spectral range of 1.20–2.98 μm with an out-of-pump power enhancement of 4.3 dB at shorter wavelengths, 2.5 dB at longer wavelengths, and a bandwidth extension of 262 nm, compared to the supercontinuum generated with an optimal but constant dispersion profile. [ABSTRACT FROM AUTHOR]

Mid‐infrared supercontinuum (mid‐IR SC) sources in the 2–20 µm molecular fingerprint region are in high demand for a wide range of applications including optical coherence tomography, remote sensing, molecular spectroscopy, and hyperspectral imaging. Herein, mid‐IR SC generation is investigated in a cascaded silica‐ZBLAN‐chalcogenide fiber system directly pumped with a commercially available pulsed fiber laser operating in the telecommunications window at 1.55 µm. This fiber‐based system is shown to generate a flat broadband mid‐IR SC covering the entire range from 2 to 10 µm with several tens of mW of output power. This technique paves the way for low cost, practical, and robust broadband SC sources in the mid‐IR without the requirement of mid‐infrared pump sources or Thulium‐doped fiber amplifiers. A fully realistic numerical model used to simulate the nonlinear pulse propagation through the cascaded fiber system is also described and the numerical results are used to discuss the physical processes underlying the spectral broadening in the cascaded system. Finally, recommendations are provided for optimizing the current cascaded system based on the simulation results. [ABSTRACT FROM AUTHOR]