Integriert-optischer Wellenleiter

The invention relates to an integrated optical waveguide extending along the surface of a substrate body, in particular a lithium niobate crystal, and provided with a thin strip-like coating at least along one part of its length, the thickness of said coating not being sufficient to guide a mode, said coating having a greater refractive index than that of the waveguide. The invention is based on the task of modifying such an optical waveguide which can be monomodal or multimodal in such a way that a formation of the optical field distribution of the light waves guided in the waveguide is possible both in the direction of the surface normals as well as perpendicular thereto within a wide range of limits along the waveguide. This task is solved by the invention by the fact that the optical waveguide is covered along the width of the substrate surface by the strip-like thin coating to a partial extent at the most