Ferroelectric oxide thin films for photonic applications

Ferroelectric oxide thin films have been synthesized by metal- organic chemical vapor deposition for potential applications in OEICs. Initial emphasis has been on the BaTiO₃ system because of its excellent electro-optic and non-linear optical properties. Epitaxial thin films have been prepared with excellent ferroelectric properties. Second-order non-linear susceptibilities of the thin films approaching the bulk value have been measured. The doping of the thin films with the rare earth ion Er has been achieved. Strong characteristic 4f shell emission has been observed at 1.5 micron under optical excitation. This suggests that BaTiO₃ thin films may be well- suited as a gain medium for integrated optical amplifiers. Other ferroelectric epitaxial films have been synthesized including SrBaNb₂O₆ and KNbO₃ and their nonlinear optical properties measured. Prospects and challenges for integration of these ferroelectric thin films in OEICs are discussed.