On the possibility of mid-IR supercontinuum generation in As-Se-Te/As-S core/clad fibers with all-fiber femtosecond pump source

We propose and optimize theoretically a supercontinuum (SC) laser source in the mid-IR based on using As-Se-Te/As-S core/clad step-index fibers and a femtosecond all-fiber laser system at 2 μm. Numerically simulated spectra extending from ~1 μm to more than 8 μm are demonstrated for pump energy of order 100 pJ in a fiber with a core diameter of 2 μm. To the best of our knowledge, the possibility of such long-wavelength spectral conversion of pump pulses at the wavelength of 2 μm in optical fibers is demonstrated for the first time. The theoretical calculations are performed on the base of real low loss step-index As-Se-Te/As-S glass fibers with various core-clad diameter ratios.