Optical properties and structural characterisation of Erbium-activated SiO2-TiO2 planar waveguides prepared by rf-sputtering

Radio-frequency sputtering was used to prepare silica-titania planar waveguides, doped with Er3+. The films, deposited on a silica substrate, were activated with different concentrations of erbium (0.14-1.63 at.%), starting from metallic erbium. The refractive indices, the thickness and the propagation losses of the waveguides were measured. Structural information about the deposited film were obtained by waveguide Raman spectroscopy. Waveguide luminescence spectroscopy was used to investigate the spectroscopic properties of the active ion, such as the green to blue upconversion and the emission at 1.5 ?m, in this system. The dependence of the dynamical processes on the erbium content was studied.