Sn-doped SiO2 thin films were fabricated on Si substrates by the Sol-Gel method. Permanent refractive index change was found using ultraviolet (UV) laser radiation at 248 nm. The photoinduced refractive index change increased after radiation and variety in the contents of Tin. The optical and surface properties of the films were characterized using X-ray photoelectron spectroscopy (XPS) and variable angle spectroscopic ellipsometry (VASE).