| 摘要 |
PURPOSE:To obtain a large Y branch angle with small loss by branching a three-dimensional optical waveguide in a Y shape and bending branch waveguides at large angles, and forming recessed parts which reflect light at the bent parts. CONSTITUTION:The terminals of the 2nd optical waveguides formed by branching the 1st three-dimensional optical waveguide 1 on a substrate in the Y shape are bent outward at a large angle respectively to form the 3rd optical waveguides. Then, triangular recessed arts 4 are formed at the bent parts and their two surfaces are formed by cutting the bent parts slantingly, perpendicular to the surface of the substrate 10, and deeper than the waveguides, and the waveguides 2 and 3 are at the same angle to normals to reflecting surfaces 4A and 4B. Therefore, the optical waveguides 2A and 2B are at proper distance (d), so two waveguide light beams are separated completely and the refractive index of air is smaller than that of the substrate 10, so the light beams are reflected totally by the reflecting surfaces, the entirety is branched optionally and widely even when the branch angle of the waveguide 1 is small, and light loss is suppressed small. |
