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

We have experimentally demonstrated the supercontinuum (SC) generation in the As
₂
Se
₃
–As
₂
S
₃
multimaterial chalcogenide glass fiber with ultrahigh-numerical aperture (NA∼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-μm diameter As
₂
Se
₃
core and a 246-μm diameter As
₂
S
₃
cladding, the fiber exhibited a zero-dispersion wavelength near 4.5 μm, and a minimum loss around 5.2 dB/m at 5.8 μm. The generated SC spanning from 1.4 to 8.8 μm was generated in a 20-cm-long fiber pumped by a 4.8 μm laser with a short-pulse width of ∼150 fs. The numerical modeling of midinfrared supercontinuum generation in a fiber with an exceptionally high NA at 3.5 and 4.8 μm was presented as well, which were in agreement with their respective experimental results.