Local devitrification on an oxyfluoride glass doped with Ho3+ ions under Argon laser irradiation

Devitrification in a holmium-doped oxyfluoride glass has been obtained under laser irradiation. The emissions from 5 S 2 ( 5 F 4 ) and 5 F 5 levels have been studied in order to analyze structure changes by the irradiation of the laser beam. The emission spectra before and after the irradiation with 2.5 W reveal that the structure of the glass sample has been modified permanently due to the laser action. Time-resolved spectra have been analyzed in the wavelength range 720-780 nm in the glass before and after irradiation, and in glass ceramic bulk samples. Lifetime measurements as a function of the distance to the centre of the damaged zone of the irradiated glass have also been carried out, and the results confirm that the devitrification was achieved successfully. Moreover, from the analyzes of these results it can be concluded that approximately 70% of the Ho 3+ ions are located in the nanocrystals and less than 30% in the glassy phase.