Structural characterisation of Er3+ doped sol–gel TiO2 planar optical waveguides

Abstract We report on the fabrication and the structural study of TiO 2 /Er 3+ planar optical waveguides. The effects of erbium concentration and annealing temperature were first studied using the waveguide Raman spectroscopy technique. The later showed an important modification of the TiO 2 host matrix induced by the presence of the Er 3+ ions. Depending on their concentration, these ions seem to stabilize the TiO 2 amorphous phase or limit the crystallization process. This result is confirmed by transmission electron microscopy (TEM) and X-ray diffraction.