Fabrication of (K, Na)NbO3 glass–ceramics and crystal line patterning on glass surface

Crystallization behavior of (30−x)K2O–xNa2O–25Nb2O5–45SiO2 (KNNS; x = 0, 5, 10, 20 and 30) (mol%) glasses was clarified and perovskite-type nonlinear optical (K, Na)NbO3 (KNN) crystals were synthesized by using a conventional glass–ceramics method. It was found that Na2O amounts over around x = 10 mol% were necessary to form perovskite-type KNN crystals showing second-harmonic generations. The substitution of K+ and Na+ ions was confirmed from X-ray diffraction (XRD) analysis. A continues-wave of Yb:YVO4 fiber laser (wavelength: 1080 nm) was irradiated onto CuO doped KNNS; x = 10 (Cu–KNNS) surface. The absorption coefficient of this Cu–KNNS glass was determined to be α = 5.0 cm−1. Perovskite-type KNN crystals were patterned in the condition of the laser power of >1.20 W and the laser scanning speed of S = 7 μm/s, and their structure was determined by Raman scattering spectra and XRD analysis.

Research highlights
► Crystallization behavior of (30−x)K2O–xNa2O–25Nb2O5–45SiO2 glass were clarified.
► (K, Na)NbO3 glass–ceramics were synthesized.
► (K, Na)NbO3 crystal were patterned by laser-induced crystallization technique.