Experimental study on chemical mechanical polishing of chalcogenide glasses

Chalcogenide glasses (Ge₁₀As₄₀Se₅₀) are one of the core components of the athermalized infrared optical system. Because of material properties, its processability is limited, and surface defects are difficult to control. The chemical nature of Ge₁₀As₄₀Se₅₀ has been established, which can react with sodium hydroxide and hydrogen peroxide (H₂O₂). In this paper, experimental studies are further carried out to investigate the effect of chemical-mechanical polishing on the surface. As a result, both agents can improve the surface quality effectively. When the concentration of H₂O₂ is about 10 wt. % to 15 wt. %, the best result can be obtained, in which case the surface microdefect and surface roughness are significantly improved with the surface roughness RMS≈0.31  nm.