OPTICAL WAVEGUIDE AND ITS PRODUCTION

摘要

PURPOSE:To provide the optical waveguide consisting of an epitaxial film having good crystallinity. CONSTITUTION:A substrate 7 and the optical waveguide layer 10 consist of the same material and a buffer layer 9 of a different kind lower in refractive index than the optical waveguide layer 10 is formed between this substrate 7 and the optical waveguide layer 10. Inexpensive materials having good crystallinity are usable for the substrate 7. Consequently, the epitiaxial film 10 formed of the same material as the material of the substrate 7 has decreased lattice strains and forms highly safe crystals. There is thus an effect of making it possible to obtain the optical waveguide having excellent optical characteristics.