Second harmonic generation from thermally poled Ge-S glass system

Abstract

Second harmonic generation was observed from thermally poled GeSx (x = 3, 4, 5, 6) glass system. The intensity of second harmonic generation depended on the S content. From x = 3 to 5, the generation increased with increasing S content, and then decreased at x = 6. There was apparent dependence of the second harmonic generation on poling temperature. The maxima appeared by poling at near glass transition temperature. By electron spin resonance and Raman scattering measurements before and after poling, it is evident that defects were formed by poling and the structure was deformed, which could relate to the generation. The relaxation of the generation was interpreted according to a recombination of defects and to a relaxation of structural deformation.