New oxyfluoride glass with high fluorine content and laser patterning of nonlinear optical BaAlBO3F2 single crystal line

A new oxyfluoride glass of 50BaF2-25Al2O3-25B2O3 (mol. %) with a large fraction of fluorine, i.e., F/(F + O) = 0.4, was prepared using a conventional melt-quenching method in order to synthesize new glass-ceramics containing nonlinear optical oxyfluoride crystals. The refractive index at 632.8 nm and ultra-violet cutoff wavelength of the glass were 1.564 and ∼200 nm, respectively. Eu3+ ions in the glass showed a high quantum yield of 88% in the photoluminescence spectrum in the visible region. BaAlBO3F2 crystals (size: 50-100 nm) showing second harmonic generations were formed through the crystallization of the glass. Lines consisting of BaAlBO3F2 crystals were patterned successfully on the glass surface by laser irradiations (Yb:YVO4 laser with a wavelength of 1080 nm, laser power of 1.1 W, scanning speed of 8 μm/s). High resolution transmission electron microscope observations combined with a focused ion beam technique indicate that BaAlBO3F2 crystals are highly oriented just like a single crystal. The present study proposes that the new oxyfluoride glass and glass-ceramics prepared have a high potential for optical device applications.