Nanostructuring in glasses with composition close to KTiOPO4

Two glasses, having the 90(K2O · 2TiO2 · P2O5) · 10(K2O · 2B2O3 · 7SiO2) and 80(K2O · 2TiO2 · P2O5) · 20(K2O · 2B2O3 · 7SiO2) molar compositions have been subjected to isothermal heat treatments in order to find the more suitable conditions to obtain transparent nanostructured glasses exhibiting non-linear optical activity. The samples were examined by differential thermal analysis, X-ray diffraction, scanning electron microscopy and their second harmonic generation (SHG) was evaluated using a pulsed solid state laser. Transparent nanostructured sample exhibiting non-linear optical activity was obtained for the 80(K2O · 2TiO2 · P2O5) · 20(K2O · 2B2O3 · 7SiO2) glass by proper heat treatment performed at temperature lying in its glass transition range.