Local devitrification of Dy3+ doped Ba2TiSi2O8 glass by laser irradiation

The Ba2TiSi2O8 (BTS) is a well known piezoelectric, ferroelectric and non-linear crystal. In this work, nanocrystals of BTS have been obtained by different thermal treatments of precursor glasses. The glasses were fabricated from BaO-TiO2-SiO2 and doped with Dy2O3 using the melt quenching method. Thermal treatment in an electrical furnace at 740 degrees C was used to obtain transparent glass ceramic samples, which are formed by an amorphous matrix containing BTS nanocrystals, with an average size of 35 nm confirmed by X-ray diffraction. Moreover, a localized area in the precursor glass has been irradiated by continuous wave (c.w.) Ar-laser or femtosecond (fs) pulsed laser. Evidence of the changes induced by laser irradiation is confirmed by spectroscopic comparison of irradiated regions with the precursor glass and glass ceramic samples. The emission spectra corresponding to the Dy3+: F-4(9/2) -> H-6(13/2) (578 nm), F-4(9/2) -> H-6(1/12) (670 nm) and F-4(9/2) -> H-6(9/2) (757 nm) transitions were obtained under laser excitation at 473 nm. These measurements confirm the incorporation of the Dy3+ ions into the BTS nanocrystals which produces an enhancement of luminescence and makes it an attractive material for optical amplification. (C) 2010 Elsevier B.V. All rights reserved.