Glass is generally classified into oxide glass and non-oxide glass by main components.
The oxide glass is further classified into silicate glass, borate glass, phosphate glass, and the like.
Non-oxide glasses are few in variety and quantity, mainly chalcogenide glass and halide glass. The anion of chalcogenide glass is mostly sulfur, selenium, tellurium, etc. It can cut off short-wavelength light and pass through yellow and red light, as well as near and far-infrared light, and its resistance is low, with switch and memory characteristics. Halide glass has a low refractive index, low dispersion, and is often used as an optical glass.