Sol–gel derived Ce3q-doped aluminosilicate planar waveguides: a study by X-ray photoelectron spectroscopy

Sol–gel derived aluminosilicate planar waveguides doped with cerium ions have been produced using the dip-coating technique. Optical characterisation of the waveguides has been performed by m-lines technique. Waveguide Raman Spectroscopy showed that while crystallisation occurs at 10008C, heat treatment at 9008C yields films which are totally amorphous. X-ray photoelectron spectra clearly indicate that cerium is present as Ce3q ions. Moreover, surface atomic ratios determined by XPS demonstrated that the measured concentrations of cerium ions are proportional to the targeted ones, even if slightly lower. Finally, depth profiles demonstrated that the films are homogeneous on a wide scale and that cerium could have a catalytic effect on the elimination of carbon impurities on the outer surface of the samples. q1999 Elsevier Science B.V. All rights reserved