Photosensitive properties of a tin-doped sodium silicate glass for direct ultraviolet writing

In this letter, the fabrication of channel waveguides by direct UV writing into a bulk tin-doped multicomponent silicate glass is presented. Different laser powers and scan rates were employed and optimized to avoid surface ablation. The best results were obtained at a laser power of 95 mW and at a scan speed of 10 mm/min, where a refractive index change of 1.5×10−3 was estimated and an attenuation loss of 3.3 dB/cm was measured using the cutback method. A morphological investigation of the glass end facets was performed in order to assess the surface effect of the laser exposure.