A Minireview of the Natures of Radiation-Induced Point Defects in Pure and Doped Silica Glasses and Their Visible/Near-IR Absorption Bands, with Emphasis on Self-Trapped Holes and How They Can Be Controlled
Figure 5
(a) Visible/near-IR spectra of a low-OH F-doped-silica-core optical fiber at selected times during continuous γ-irradiation at 1 Gy/s in the dark. (b) A decomposition of similar spectra of a low-OH high-purity-silica-core fiber concomitantly irradiated and recorded under identical conditions. This decomposition was achieved by first separating the red/near-IR peaks from the induced absorptions at higher energies by means of cut-and-try subtractions of several members of the full set of recorded spectra, of which the four displayed in (a) are corresponding examples (adapted from [44]). Superposed circles and squares in (b) represent in arbitrary units optically stimulated release of trapped positive charge from an X-irradiated a-SiO2 thin film (data from [41]).
