Observations were made of photoluminescence which originated from defects that were created by the visible and near-infrared irradiation of vitreous silica. Three photoluminescence bands, at 283, 468 and 558nm, exhibited excitation spectra which peaked at 250nm. This corresponded to O vacancy absorption. The observed photoluminescence bands were attributed to singlet-singlet transitions of the O vacancy (283nm), and to the radiative recombination of separated carriers at vacancy-interstitial pairs, VO-Oi (468nm) and VO-(O2)i (558nm).

Luminescence and Defect Formation by Visible and Near-Infrared Irradiation of Vitreous Silica. M.Watanabe, S.Juodkazis, H.B.Sun, S.Matsuo, H.Misawa: Physical Review B, 1999, 60[14], 9959-64