Fabrication and Characterization of Three-hole As 2 S 3 Suspended-Core Fibers Based on Robust Extrusion

We have prepared a three-hole AsS suspended-core fiber (SCF) with an As 2 S 3 core and a Ge 15 Sb 10 Se 75 cladding via a robust technique combining the traditional rod-in-tube process with the preform extrusion method. The as-fabricated chalcogenide SCF has a core diameter as small as $2.33~\mu \text{m}$ . The lowest fiber loss is 0.62 dB/m at $2.71~\mu \text{m}$ and the nonlinear Kerr coefficient is up to 4251.96 $\text{W}^{-1}\cdot \text {km}^{-1}$ at $1.55~\mu \text{m}$ . The simulation of the dispersion distribution in the fiber indicates that there are two zero-dispersion wavelengths (ZDW) at $2.57~\mu \text{m}$ and $6.35~\mu \text{m}$ , respectively, and the ZDW can be further turned into a shorter wavelength if the core size of the fiber is reduced via the in situ tapering process. This makes the fiber much easier to be pumped by cheap and commercial lasers available. Finally, a broad supercontinuum spectrum covering $1.5-9.5~\mu \text{m}$ is obtained in the SCF pumped by an optical parametric amplifier laser system at $3~\mu \text{m}$ .