Fig. 1. Relationship between incident and transmitted laser powers of 2.053 μm laser through 20 cm length，12 μm core diameter, uncoated and AR-coated As₄₀S₆₀ single mode fibers ^[8]

Fig. 2. Transmission of 5.4 μm CO CW laser through As₄₀S₆₀ and Ge₁₀As₃₀S₆₀ fibers under forced air-cooling conditions ^[10]

Fig. 3. Relationship between input and output powers of 10.6 μm CO₂ laser through 100 cm long Ge₁₅As₂₅Se₄₀Te₂₀ fiber ^[14]

Fig. 4. Chalcogenide LMA-PCFs with different structural geometries ^[16]

Fig. 5. Experiment and result of 2 μm CW laser transmission ^[18]. (a)(b)(c)Devices；(d)relationship between incident and output powers through 47 cm long fiber

Fig. 6. Cross-sectional SEM images of hollow-core Bragg fiber at various magnifications ^[22]

Fig. 7. Cross sections of fiber preform and hollow-core Bragg fiber^[23]. (a) Fiber preform; (b) hollow-core Bragg fiber

Fig. 8. Chalcogenide HC-PCFs with different structures ^[25]. (a) Hexagonal lattice cladding structure; (b) Kagome cladding structure

Fig. 9. Cross-sectional SEM image of chalcogenide negative curvature fiber ^[36]

Fig. 10. Transmission performances of CO₂ laser in chalcogenide negative curvature fiber ^[36]. (a) Measured optical loss spectrum; (b) intensity distribution of CO₂ laser over fiber core

Fig. 11. Cross sections of fiber under different inner tube pressures ^[39] . (a) 0; (b) 3.5×10³ Pa; (c) 4×10³ Pa；(d) 4.5×10³ Pa

Fig. 12. Characterization of fiber performances^[39]. (a) Cross section of arch-shape negative curvature fiber；(b) transmission band measured by FTIR