SECOND HARMONIC GENERATION (SHG) FROM THERMALLY POLED Zn-Bi-Te-O-F GLASSES WITH VERY LONG RELAXATION TIME

Second harmonic generation (SHG) was observed from a thermally poled Zn-BiTe-O-F glass system measured by Maker-Fringe pattern using Nd: YAG high power pulse laser. Both Bi and F were necessary for the generation, otherwise no SHG was observable from the glasses without Bi or F. The intensity of the generation depended on the F content. In the SHG from poled glasses, short relaxation time has been neck of the practical use. Although the generation of the common thermally poled glasses relaxed within 3 days, for those of the present glasses, the generation was maintained over 1 month. This is considered to be explained by the interaction of the dipoles between the large Bi ions binding the F ions inside of glasses. HIROYUKI NASU et al. 12