High-contrast waveguides in sputtered pure TeO2 glass thin films

We present a technological approach to the realization of channeled optical waveguides, starting from reactively sputtered tellurite glass thin films, grown on silica-coated 4 '' Si wafers. In particular, optical lithographic process and etching recipes have been developed to overcome the solubility of TeO2 films in aqueous solutions, and to process them into high-index contrast structures with minimized post-etch roughness. Optical tests on preliminary rib waveguide geometries feature 6.3 dB/cm propagation loss for fundamental TE mode at lambda = 1.5 mu m. (C) 2008 Optical Society of America