Abstract Materials with high deep-ultraviolet (DUV; λ<300 nm) transmission are important for many industrial applications. Fluoride single crystals and various glasses, pure SiO2, fluoride, phosphate, multicomponent silicates, and organic materials (PMMA), were investigated. The role of intrinsic absorption (UV edge) due to electron transitions between the main components, and extrinsic absorption due to trace impurities, effect of polyvalent ions, redox behavior, and radiation-induced transmission loss were considered. The optical basicity and optical properties were used to order the materials.