ABSORPTION-SPECTRA AND LUMINESCENCE OF OXYGEN-DEFICIENT CENTERS IN A TITANOSILICATE GLASS SYNTHESIZED IN A STEADY LASER PLUME - I - ABSORPTION-SPECTRA

The absorption spectra of titanosilicate glasses with the titanium con centration similar to 0.1%-3% by weight were investigated in the wavel ength range 225-460 nm. These glasses were synthesised in a steady las er plume in an atmosphere of air or nitrogen at normal pressure. Synth esis in these two atmospheres gave rise to Ti ions of different valenc e in the glasses. For the same Ti concentration the intensity of the c haracteristic absorption bands of titanium in its reduced states (Ti2, Ti3+) with maxima at lambda similar to 278 and 306 nm were 3 - 6 tim es higher when the synthesis took place in nitrogen. The enhancement o f the 278 nm band was approximately half that of the band at 306 nm. C lear-cut strong absorption in the UV range at 260 - 280 nm as well as strong absorption in the visible range at 400 - 500 nm, observed for t he First time for titanium-doped silica glass, were the results of a r ecord-high concentration of Ti3+ ions, compared with the concentration s found in bulk glass samples prepared by other technologies such as m elting, reduction of Ti4+ ions, and plasma hydrolysis.