Abstract: A light waveguide device including a thin film of a polymer material capable of exhibiting the electro-optic effect. The composite structure of first electrode, buffer layer, thin film layer, second buffer layer and second electrode covering substantially the entire area of the adjacent major surface of the thin film layer, is disposed on a substrate which underlies the second electrode. In an alternative embodiment the first buffer layer is a strip-shaped ridge on those thin film regions only which are in registration with the first electrode. Various types of integrated optical components can be readily implemented. Embodiments of a phase modulator, directional coupler, switch and bending section are described.