Effect of IR femtosecond laser irradiation on the structure of new sulfo-selenide glasses

We report results of a systematic study to evaluate for the first time, the relationship between compositional variation and photo-sensitivity of new glasses in the Ge–Sb–S/Se system with varying ratios of chalcogen (S/Se), upon IR femstosecond laser exposure. It is shown that the photo-sensitivity of the glass depends on the glass composition and that IR femtosecond laser irradiation in this system results in near-surface photo-expansion. Glass structure modification as a function of S/Se ratio and the influence of laser dose has been characterized using micro-Raman spectroscopy and is correlated to the resulting photo-expansion. As compared to other widely studied binary chalcogenide glass systems, photo-expansion was found to vary with the Se content. Such modification opens the pathway towards the laser writing of photonic devices in the surface of the material.