Red photoluminescence and optical absorption in hydrogen-treated GeO ₂-SiO₂ sol-gel-derived planar waveguides

We report the effects of post-deposition, reducing atmosphere heat treatment on the optical absorption, and photoluminescence response of 45 GeO₂-55 SiO₂ thin films produced using the sol-gel process. With increasing heat treatment, a linear increase in the 242 nm absorption peak (associated with oxygen-deficient germania centers) is found to contrast a reduction in the intensity of red photoluminescence (attributed to hydrogen centers in the glass structure). These results are discussed in terms of the photosensitive response of these materials.