Abstract
Optical absorption spectra of copper-containing silicate glasses were determined and the effects of UV irradiation on the spectra were studied. Oxalic acid was used as a reducing agent in order to obtain monovalent copper ions. Several absorption bands were observed as a result of UV irradiation at wavelengths of 430–480, 565–570, 620–690, 720–790, 800–900 and 307–310 nm. These bands were interpreted in terms of photochemical reaction and attributed to color centers, cupric ions (Cu
1++), metastable copper atoms (Cu
o), and aggregates of copper atoms which were induced by UV irradiation.