Fig. 1. Diagrams of extrusion process. (a) Principle of extrusion die; (b) state after the metal module is squeezed in; (c) extrusion process of core glass into cladding glass; (d) preform extruded out

Fig. 2. Infrared transmission spectra and thermal expansion curves of glass samples. (a) Infrared transmission spectra of As₂Se₃ and As₂S₃; (b) thermal expansion curves of As₂Se₃ and As₂S₃

Fig. 3. Refractive index, NA, simulated dispersion curves and fundamental mode effective refractive index of fiber. (a) Refractive index of As₂Se₃ and As₂S₃, and calculated NA; (b) simulated dispersion curve of fiber and fundamental mode effective refractive index

Fig. 4. Cross-section image and loss of the fiber. (a) Cross-section of the fiber; (b) measured optical loss of the fiber (inset: output light spot image)

Fig. 5. Supercontinuum spectrum of optical fiber at different pumping wavelengths