Spatially selected synthesis of LaF3 and Er3+-doped CaF2 crystals in oxyfluoride glasses by laser-induced crystallization

摘要

Oxyfluoride glasses with a small amount of NiO are prepared using a conventional melt quenching technique, and the spatially selected crystallization of LaF3 and CaF2 crystals is induced on the glass surface by irradiations of continuous wave lasers with a wavelength of lambda = 1064 or 1080 nm. Dots and lines including LaF3 crystals are patterned by heat-assisted (300 degrees C) laser irradiations (lambda = 1064 nm) with a power of P = 1 W and an irradiation time of 10 s for dots and a scanning speed of S = 5 mu m/s for lines. Lines consisting of CaF2 crystals are also patterned in an ErF3-doped oxyfluoride glass by laser irradiations (lambda = 1080 nm) with a power of P = 1.7W and a scanning speed of S = 2 mu m/s, and the incorporation of Er3+ ions into CaF2 crystals is confirmed from micro-photoluminescence spectrum measurements. It is proposed that the lines patterned by laser irradiations in this study are consisted of the composite of LaF3 or CaF2 nanocrystals and SiO2-based oxide glassy phase. It is demonstrated that a combination of Ni2+ -dopings and laser irradiations is effective in spatially selected local crystallizations of fluorides in oxyfluoride glasses. (C) 2008 Elsevier Inc. All rights reserved.