Mid-infrared supercontinuum generation in low-loss single-mode Te-rich chalcogenide fiber

A single-mode Te-rich chalcogenide (ChG) fiber for mid-infrared has been fabricated via an isolated extrusion method. The optical loss of the fiber is 3-4 dB/m in a range of 6.5-10.5 µm. Mid-infrared (MIR) supercontinuum (SC) generations were experimentally investigated in the step-index single-mode fiber with femtosecond laser pulse from an optical parametric amplifier (OPA). By pumping 17 cm-long fiber at 5 µm and 8 µm, the spectra spanning from 1.8 to 15 µm and 2.3 to 14.5 µm, respectively, were observed. The results show that the efficiency of SC generation is highest by pumping at near zero dispersion wavelength in single-mode fiber. It reveals that the superiority of single-mode fiber in SC generation over multimode is the elimination of high-order modes (HOMs) interaction. Besides, a repeat SC experiment was carried out for fiber stability test after half a year.