Second Harmonic Generation in Poled Tellurite Glasses

Abstract
Second harmonic generation has been observed in electrically poled tellurite glasses with 80TeO2·10Li2O·10Nb2O5 and 70TeO2·15Li2O·15Nb2O5 compositions. The poling was carried out at 200 to 300°C for 30 min under applied dc field of 4 to 5 kV. To explain the mechanism generating the second-order nonlinearity in the poled tellurite glasses, it is proposed that strong local polarization is caused by migration of lithium ions and/or periodic orientation of lone pairs of electrons in the tellurium ions.