Photonic devices enabling light modulation and switching are of major importance for modern telecommunication. Silicon-based electro-optic modulators are intensively investigated because of their direct compatibility to CMOS fabrication processes. However, the performances of Si based modulators are intrinsically limited, in terms of data transmission rate and energy consumption. To overcome this limitation, ferroelectric oxides with naturally strong electro-optical coefficients combined to small footprint could be ideal candidates for high-speed modulators. We have designed an integration scheme to implement these materials on SOI photonic platform, for 1.55 μm Datacom systems. Monolithic integration of ferroelectric oxides on SOI via SrTiO3 templates is presented. The devices are based on a horizontal (crystalline Si / ferroelectric oxide / amorphous Si) slot waveguide configuration.