Organic-inorganic hybrid material (SIAZO-VP2) for nonlinear optics was prepared by the sol-gel processable monomer derived from 3-isocyanatopropyltriethoxysilane with hydroxy-functionalized nonlinear optical chromophores. The measured value of NLO coefficient strongly depended on conditions such as poling temperature, poling time and heating rate. The maximum value of SIAZO-VP2 film which was heated at 200 degreesC exhibited d(33) = 64 pm/V in Maker-fringe measurement. It was found that the thermal stability of the film was greatly enhanced as poling time increased and a poling temperature became higher Using this hybrid material, we fabricated a vertically asymmetric coupled electrooptic modulator. The resulting device exhibited a good performance with the extinction ratio of ca. 9 dB, the half wave voltage of 5 V and the bandwidth of 1.5 MHz at the wavelength of 633 mn.