We describe the preparation of zirconia and hybrid zirconia-ORMOSIL planar waveguides by sol-gel technology at room temperature. Acetic acid was used as chelating agent to stabilize the zirconia precursor. Multimode light guiding was demonstrated for the first time in zirconia films prepared by the sol-gel method. The properties of the films, refraction index, thickness, and transparency as well as structural characterization using Fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy (XPS), thermal analysis, and X-ray diffraction (XRD), were studied. The zirconia film contains propoxy, acetate, and hydroxyl ligands. In the zirconia-ORMOSIL films Zr-O-Si bonds were found, although homocondensation bonds are favored. The mechanism proposed for the structural results involves condensation of oligomeric species that react by ligand exchange. XRD show wide peaks at angles in area of 2Θ ) 4-10°. These peaks can be attributed to oligomeric structures with d spacing values of about 10 Å. The hybrid films are hydrophobic and XPS measurements shows that the surface is covered mainly by organic groups of the ORMOSIL. Films doped by pH indicator Methyl Red showed reversible response to acid and base vapors; this opens the possibility to use such films as waveguide-based optical sensors.

Room temperature persistent spectra hole burning in Sm2+doped silicate glasses prepared by the solgel process Appl.Planar waveguides of TiOrorganically modified silanes deposited on glass substrates were prepared by the sol-gel method, either in a pure form or doped by red perylimide laser dye, and their optical properties characterized. The refractive index increases and film thickness decreases as TiOz contents rise. Waveguiding in the pure film and the trapped luminescence in the doped films were measured. Typically three guided modes were observed.

Glass waveguiding films were prepared from titania and modified silica using the sol-gel method and doped by the laser dye rhodamine B. The guided and amplified fluorescence (pumped by a double frequency Nd-YAG laser) was coupled out either by static grating written on the film or by a prism. The gain of the emitted superradiance was determined from the amplified spontaneous emission intensity dependence on the pumped strip length. A maximum net gain of 54 dB/cm was measured.

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