ABSTRACTFerroelectric oxide epitaxial thin films are potentially important for a variety of guided-wave electro-optic and non-linear optical applications. Metalorganic chemical vapor deposition has been used to synthesize epitaxial thin films of a number of ferroelectric oxides. The films now have sufficient optical quality to enable the fabrication of waveguide devices including electro-optic modulators and optical amplifiers for 1.54 microns.