Optical second harmonic generation in transparent tellurite glass-ceramics containing BaTiO3

Optical second harmonic generation has been observed in transparent tellurite glass-ceramics of BaO-TiO2-TeO2 system. BaTiO3 and unidentified crystalline phase precipitate from 15BaO . 15TiO(2) . 70TeO(2) glass. The temperature of maximum rate of nucleation for these crystalline phases is estimated to be 380 degrees C. The BaTiO3 crystal precipitated is a cubic phase with lattice parameter of 0.4045 nm, which is slightly larger than the value reported in the JCPDS cards. The optical second harmonic intensity of the present transparent tellurite glass-ceramics is comparable to the intensity of poled tellurite glasses although the BaTiO3 phase precipitated is cubic and the crystal face is randomly oriented in the glass-ceramics. For instance, the second harmonic intensity of the present transparent tellurite glass-ceramics is about twice as large as that of 20WO(3) . 80TeO(2) glass poled at 280 degrees C under the external electric field of 3 kV, the second-order nonlinear coefficient, d(33), of which is 0.10 pm/V.