Precision fabrication of a four-hole Ge₁₅Sb₁₅Se₇₀ chalcogenide suspended-core fiber for generation of a 15–12 µm ultrabroad mid-infrared supercontinuum

We reported the fabrication of a high-precision, long-length (>10 cm), four-hole, and As-free Ge15Sb15Se70 chalcogenide (ChG) suspended-core fiber (SCF) preform based on the computerized numerical control (CNC) precision mechanical drilling method. Four holes of the preform were highly symmetrical and have a depth of 103 mm. A fiber with a core diameter of 7 µm, cladding diameter of 300 µm, and regular air hole structure was drawn by using inflating methods through accurately controlling the inflation pressure. Theoretical simulation of the zero-dispersion wavelength (ZDW) of this fiber was located at approximately 3.3 µm. Under pumping at 3.5 µm with an average power of 23 mW, the fiber with length of 14 cm generates a mid-infrared (MIR) supercontinuum (SC) that spans from 1.5–12 µm within a 30 dB dynamics range.