Thermal poling of photosensitive glasses containing Ag+ and Ce3+ ions

We present the results on the crystallization of photo-thermo-refractive glass under thermal poling and ultraviolet (UV) irradiation followed by heat treatment. Poling was carried out at a temperature of 300 °C and a voltage of 400−1000 V. A femtosecond laser with a wavelength of 343 nm was used as UV sources. The studies were carried out using optical microscopy, optical absorption and Raman scattering. It is shown that in the subanode layer of the glass after poling, subsequent UV irradiation and heat treatment, crystallization of glass is completely suppressed. After the poling and the heat treatment cesium ions are also recharged in this layer Ce³⁺ → Ce⁴⁺. The mechanisms of the crystallization suppression and ion recharge in the poled region of the glass are discussed.