Effect of poling temperature on optical second harmonic intensity of sodium zinc tellurite glasses

Poling temperature dependence of optical second harmonic intensity has been examined for Na2O-ZnO-TeO2 glasses. All the glasses exhibit such a tendency that the second harmonic intensity increases, experiences a maximum, and decreases as the poling temperature increases. The poling temperature giving rise to the maximum second harmonic intensity, which we call an optimum poling temperature, correlates with glass transition temperature; there exists a linear relation between them. This phenomenon indicates that the structural change of glass network near the glass transition temperature affects the orientation of electric dipoles with a long range order which induces the second harmonic generation. We suggest that some electrochemical reactions take place on the anode-side surface of glass at around the glass transition temperature where viscous flow is allowed and disturb the orientation of electric dipoles. (C) 1998 American Institute of Physics.