A new type of organic chromophore group/SiO_2-TiO_2 second-order nonlinear optical (NLO) materials has been obtained by sol-gel process from titanium butoxide [Ti(OBu)_4] and an alkoxysilane dye (ASD) synthesized by coupling disperse orange-3 (DO-3) with (3- glycidoxypropyl) trimethoxysilane (KH-560). The phase diagram of the system was investigated and a stable hybrid sol was prepared. Research by X-ray energy dispersion spectrum (EDS) and transmission electronic microscope (TEM) shows that the hybrid sol particles consist of SiO_2, TiO_2 and the organic chromophore group and the size of the particles is about 20～80 nm. Moreover the mechanism of the complexing reaction was also investigated by Fourier transform infrared spectrometer (FTIR) in the preparation process of the hybrid sol. The ordering parameter Φ of the transparent poled film of the hybrid material, prepared by spin- coating, thermal curing and corona poling at 190 ℃ for 1 hour, can reach 0.38 and the second-order nonlinear optical polarizability X~(2) is 1.43 * 10~(-7) esu according to one dimensional rigid oriented gas model (1DROGM). The poled film exhibits good orientation stability and its glass transition temperature is 196 ℃.

Key words: HYBRID MATERIALS, NON LINEAR OPTICS, ORIENTATION, ORIENTATION, AZO DYES, SILANE P, SOL-GEL PROCESS