G. Brusatin et al., MICROSTRUCTURAL AND OPTICAL-PROPERTIES OF SOL-GEL SILICA-TITANIA WAVE-GUIDES, Journal of non-crystalline solids, 220(2-3), 1997, pp. 202-209
Two micron silica-titania coatings made by single step sol-gel dip-coa
ting were prepared as planar waveguides. Acid catalyzed solutions of m
ethyltriethoxysilane (MTES) mixed with tetraethoxysilane (TEOS) and te
trabutoxytitanate were used as precursors. Purely inorganic and crackf
ree silica-titania coatings were obtained after annealing at 500 degre
es C. The waveguides had propagation losses, 0.3 dB/cm, of the same or
der as thin silica-titania films prepared without MTES, Films were stu
died by infrared spectroscopy, Rutherford backscattering spectrometry,
nuclear reactions analysis and elastic recoil detection analysis. The
waveguide structural composition after annealing at 500 degrees C was
found to be similar to MTES and TEOS derived silica-titania coatings.
The waveguides were characterized by measuring refractive index, poro
sity and shrinkage, with thermal treatment. The MTES derived films sho
wed a higher shrinkage during annealing but the same refractive index
and porosity as the TEOS derived waveguides. (C) 1997 Elsevier Science
B.V.