Fig. 1. Schematic diagram of chalcogenide glasses purification process. (a) Preparation of glass clinker; (b) chlorine gas dehydrogenation; (c) dynamic distillation; (d) integral distillation; (e) aluminum deoxygenation and purification; (f) integral distillation

Fig. 2. Refractive index curves of core rod and skin tube and numerical aperture of fiber

Fig. 3. Schematic diagram of multi-mode and single-mode chalcogenide glass fibers preparation process

Fig. 4. Schematic and physical diagram of three-dimensional laser scattering microscopy imaging system

Fig. 5. Infrared absorption spectra of glass prepared with different Cl₂ input volume

Fig. 6. Infrared absorption spectra and mass fraction of oxygen for C3 and C3A samples

Fig. 7. Relationship between absorption coefficient and mass fraction of oxygen for As₄₀S₆₀ glass at 7.6 μm

Fig. 8. Comparison of internal stripes of As₄₀S₆₀ glasses under different discharge temperatures

Fig. 9. Scattering imaging, image after adding false color and gray value distribution for As₄₀S₆₀ glasses under different discharge temperatures. (a)(d)(g) 400 ℃; (b)(e)(h) 450 ℃; (c)(f)(i) 500 ℃

Fig. 10. SEM test results. (a) SEM image of C3A700 glass; (b) composition testing of heterogeneous particles

Fig. 11. Loss spectra for C3 and C3A fibers (inset is end surface of multi-mode fiber)

Fig. 12. Scattering test results of fibers. (a) Scattering image of C3A700 fiber; (b) scattering image of C3A fiber; (c) gray value distribution of scattering image

Fig. 13. Relationship between output power P_out and input power P_in in fiber

Fig. 14. Mode field distribution of single-mode fiber at 2 μm. (a) LP01 mode; (b) LP11 mode