This SBIR Phase II project proposes to develop the Liquid Phase Epitaxy (LPE) of potassium tantalum niobate (KTN) on a cubic perovskite substrate. In this manner both components of the film/substrate composite may be optimized for device performance. KTN has almost two orders of magnitude higher electrooptic coefficients than current generation lithium niobate waveguides, which would permit shorter path lengths, lower bias voltages or some combination of the two. The new, low dielectric constant substrate material developed in Phase I will enable better matching of the effective microwave dielectric constant to the optical dielectric constant of the film material and achieve lower bias fields. In Phase II, the researchers will develop the new substrate material to commercial quality and size. LPE of KTN will be developed from a new innovative flux system that allows excellent control of growth and superior film properties. Both film and substrate will be fully characterized and optimized as a composite. The process and product will be scaled up to full commercial size. IPI will interact with strategic partner device manufacturers to optimize the material and realize device applications. <br/><br/>Electrooptic devices are used in any photonics application where an electrical signal can be used to change the state of a beam of light. While the best-known applications for electrooptic devices are in telecommunications, customers can be found wherever light is used to move information including optical computing, analog and digital signal processing, information processing and sensing. Devices include phase and amplitude modulators, Q-switches, multiplexers, switch arrays, couplers, polarization controllers, deflectors, correlators, sensors, potential transformers and optical parametric oscillators. Potential customers are noticeably found in both the electric power industry and the military. Initial applications in sensors will have an immediate potential for impact in reliability of electric power distribution through failure anticipation and prevention and conservation of electric power through monitoring and control. The proposed work will enable electrooptic modulators, switches and innovative new photonic device applications with lower costs, smaller footprints and lower power budgets. All this contributes to improvements of the infrastructure of the Internet and more rapid, lower cost deployment, especially in the local loop.