Sol-gel-processed TiO₂/SiO₂ films doped with organic azo dye have been investigated. The film was spin-coated on the ITO coated glass substrate and rapidly condensed by evaporation of the solvent from the liquid film. The thickness of the hybrid films can be varied from 0.2 to 0.6 micron. When the prehydrolyzed tetraethoxysilane (TEOS) sol and titania precursor(titanium butoxide) are mixed together with various molar ratios, the refractive index of the film may vary from 1.49 to 1.81 at 1300nm. The film is aged at 80°C for 2 h and then corona poled at 120°C for 1 h so that the dye molecules are dispersed in numerous pores of the oxide matrix. The absorbance spectra of the film measured by a UV-visible spectrophotometer show that the process of aging and poling in the sample preparation causes the pores in the oxide matrix to shrink and nonlinear molecules are aligned in the direction of the poling field and are trapped in the pores. The electro-optic coefficient r₃₃ is 42 pm/V at a fundamental wavelength of 1300nm. The nonlinearity is stable at 80°C for 2500h at least. The excellent thermal stability of the hybrid organic/inorganic film is an advantage for optical applications.

Date Published: 4 January 2008
PDF: 6 pages
Proc. SPIE 6839, Nonlinear Optics: Technologies and Applications, 68392D (4 January 2008); doi: 10.1117/12.759238

Published in SPIE Proceedings Vol. 6839:
Nonlinear Optics: Technologies and Applications
Yiping Cui; Qihuang Gong; Yuen-Ron Shen, Editor(s)