We report the nanofabrication of Bragg reflector waveguide structure based on barium titanate (BTO) epitaxial thin film grown on MgO substrate and characterized its optical transmission. A low pressure (~1 Torr) nano-lithography was used for the formation of Bragg reflector waveguide structure. We demonstrate that there is sufficient refractive index contrast to form a well-defined stop band by forming gratings in a top strip layer of Si3N4 that was grown on BTO thin film. Simulation of the optical transmission and stop band of TE mode, and electro-optic (EO) modulator tunability are discussed as well. The non-linear photonic crystal waveguides are potentially suitable as tunable optical filters and ultra-wide bandwidth modulators.