Oriented surface crystallization of lithium niobate on glass and second harmonic generation

Surface crystallization of LiNbO3 on xK(2)O .(35-x)Li2O . 30Nb(2)O(5). 35SiO(2) (0 less than or equal to x less than or equal to 35) (mol%) glasses was investigated. The c-axis orientation of surface crystallized LiNbO3 was Improved when the glass contained 10 mol% K2O. Furthermore, Li ions in the LiNbO3 crystallites were partially replaced by K ions from the glass. Transparent surface crystallized LiNbO3 films on glasses were prepared by controlled heat treatment, which showed optical second harmonic generation. The estimated second-order non-linear optical susceptibilities were d(33) = 6.40 pm/V and d(31) = d(21) = d(34) = d(15) = 1/3d(33) = 2.14 pm/V for a film 1.33 mu m in thickness prepared after heating at 620 degrees C for 3 h, when the c-axis oriented film was described by a space group C-infinity v. (C) 1999 Elsevier Science B.V. All rights reserved.