Desvitrification on an oxyfluoride glass doped with Tm3+ and Yb3+ ions under Ar laser irradiation

Desvitrification in a Tm3+ and Yb3+ codoped oxyfluoride glass has been obtained by exciting with a continuous Argon laser radiation increasing the average laser power from 144 to 2900 mW. Excitation spectra inside a locally damaged zone in a 1 mol% Tm3+ and 2.5 mol% Yb3+ codoped glass have been measured under excitation in the wavelength range 750–830 nm detecting the 2F5/2 (Yb3+) level. This curve is the result of the contribution of two different kinds of centers, the fluoride nanocrystals and the glassy phase of the glass ceramic sample created due to the irradiation. The weight of the contributions of each of the centers depends on the excitation wavelength, and from the analysis of the decay of the luminescence it can be concluded that approximately 80% of the Tm3+ ions are located in the nanocrystals and therefore less than 20% in the glassy phase.