Effect of Poling Temperature on Optical Second‐Harmonic Intensity of Lithium Sodium Tellurite Glass

Second-harmonic generation has been observed in poled 10Li2O10Na2O80TeO2 glass. The effect of poling temperature on the second-harmonic intensity has been examined. The second-harmonic intensity increases, attains a maximum, and then decreases as the poling temperature increases. In other words, an optimum poling temperature that results in a maximum second-harmonic intensity exists. The optimum poling temperature linearly increases as the glass-transition temperature increases for several types of tellurite glasses, including the present 10Li2O10Na2O80TeO2 glass. This fact suggests that the process to create a polarization that results in the second-harmonic generation is affected by the structural relaxation at the glass-transition range. The thermal stability of 10Li2O10Na2O80TeO2 glass is higher than that of 18Na2O82TeO2 (30NaO1/270TeO2) glass, as revealed via differential scanning calorimetry. As a result, the temperature range within which the poling is effective is wider for the former glass.