Abstract: Sol-Gel derived SiO$-2$/-TiO$-2$/ films were densified by scanning a CO$-2$/ laser beam across the surface. The effects of laser power and scanning rate on the morphology and optical properties of the coatings were studied. At low laser powers a depression, with rough sidewalls and approximately gaussian profile was formed in the coatings. As the laser power was increased the channels became wider and smoother, and flattened out on the bottom. At high laser powers a pair of ridges were formed in the bottom of the channel, apparently due to melting. The refractive index of the laser densified films was higher than for films fired in a furnace. Most laser densified areas supported waveguide modes but exhibited high loss. By processing at powers just below the damage threshold loss was reduced to a measurable value, 12.4 dB/cm for the TM$-0$/ mode for one sample. Annealing the films after laser processing also reduced the loss.!12
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