Nonlinear Optical Effects In Surface Crystallized 0.50TeO2–0.50 LiNbO3 Glasses

Abstract

Ever since, Borrelli1 has reported the fabrication of transparent glass-ceramics composed of ferroelectric NaNbO3 crystals, glasses and glass-ceramics have been considered as potential candidates for a variety of NLO applications. TeO2-based glasses containing ferroelectric crystals have emerged as promising candidates for nonlinear optical (NLO) applications, in the recent past. Transparent TeO2 glasses containing the crystalline phase of ferroelectric LiNbO3, have been fabricated. Since, the refractive-indices of TeO2-based glasses and LiNbO 3 crystal are compatible, the scattering losses at the glass-crystal interface is considerably small, thereby making these glasses ideal candidates for optical applications. Komatsu and co-workers2, based on their studies on the crystallization behaviour of TeO2-Li2O-Nb2O5 glasses, proposed the possibility of the fabrication of transparent TeO2-based glasses containing ferroelectric LiNbO3 microcrystallites. But the difficulty encountered, in fabricating transparent TeO2-based glasses containing ferroelectric LiNbO3 crystals, is the precipitation of an undesired non-transparent pyrochlore phase. Subsequently, Kim et al 3 reported the crystallization of LiNbO3 in TeO2-Li20-Nb205 glasses (with high Li+ content), by a two-step heat-treatment process. They have also prepared transparent tellurite glasses containing LiNbO3 crystals using an incorporation4 method in which LiNbO3 crystals have been directly dispersed in glasses of the composition 80 TeO2–15 Li2O–5Nb2O5. Since a variety of applications of these glasses are foreseen, a detailed investigation into TeO2-LiNbO3 glass-ceramics is imperative.