Modification of sol-gel TiO2 planar waveguides by Xe+ irradiation

TiO2 sol-gel optical waveguides were prepared by multi dip-coating. They were heat treated at 500 degrees C and irradiated by Xe+ ions. The implantation energy, in the MeV range, was chosen to assure a total energy deposition inside the waveguide. Additionally, after implantation, annealing treatment was performed at 200 degrees C under pure oxygen flux. The structural changes were examined by Raman spectroscopy and Transmission Electron Microscopy (TEM), and the waveguide properties were investigated by m-line spectroscopy. Significant densification of the layers and refractive index enhancement were obtained, while a strong decrease of the crystallite size was observed in the film.