PROCEEDINGS ARTICLE | January 29, 2007
Proc. SPIE. 6279, 27th International Congress on High-Speed Photography and Photonics
KEYWORDS: Oxides, Thin films, Refractive index, Reflection, Polymers, Glasses, Crystals, Gallium arsenide, Sol-gels, Electro optics
Highly transparent TiO<sub>2</sub>/SiO<sub>2</sub> films prepared using sol-gel technique doped with organic azo dye, Disperse Red 1(DR1)
have been investigated. Processing parameters such as spin speed, spin time, and ambient atmosphere, and solution
synthesis parameters such as catalysis method, alcohol dilution ratio, and component molar percentages, may affect the
film formation. The refractive index increases follow along with the raising of the molar ratio between TiO<sub>2</sub> and SiO<sub>2</sub>.
When the molar ratio between TiO<sub>2</sub> and SiO<sub>2</sub> is zero, i.e. no titania precursor in the initial solution, the refractive index is
minimum 1.49 at 1300nm, whereas when there is no TEOS in the initial solution, the refractive index is maximum 1.81
at 1300nm. The sol-gel thin film is spin-coated on ITO glass substrate with better uniformity. The electric-optic
coefficient γ<sub>33</sub>=42pm/V was measured by simple reflection technique at a fundamental wavelength of 1300nm. The
hybrid organic-inorganic sol-gel film is well balanced material in its simplicity for film formation, nonlinearity, and
thermal stability sufficient for device fabrication. Moreover, the measurement system was calibrated and the measured
electric-optic coefficient of the gallium arsenide crystal is in excellent agreement with the known value.
