Midinfrared Supercontinuum Generation in As2Se3-As2S3 Chalcogenide Glass Fiber With High NA

We have experimentally demonstrated the super-continuum (SC) generation in the As2Se3-As2S3 multimaterial chalcogenide glass fiber with ultrahigh-numerical aperture (NA similar to 1.4). The fiber preform was fabricated via a modified one-step coextrusion method before it was drawn into the small-core fiber. With a 10-mu m diameter As2Se3 core and a 246-mu m diameter As2S3 cladding, the fiber exhibited a zero-dispersion wavelength near 4.5 mu m, and a minimum loss around 5.2 dB/m at 5.8 mu m. The generated SC spanning from 1.4 to 8.8 mu m was generated in a 20-cm-long fiber pumped by a 4.8 mu m laser with a short-pulse width of similar to 150 fs. The numerical modeling of midinfrared super-continuum generation in a fiber with an exceptionally high NA at 3.5 and 4.8 mu m was presented as well, which were in agreement with their respective experimental results.