| 摘要 |
PROBLEM TO BE SOLVED: To obtain the grating coupler which can make coupling efficiency stable and high. SOLUTION: The grating coupler is constituted by forming a grating 16 on the surface of an SiO2 film 15 formed on a substrate 10, filming an optical waveguide layer 20 made of ZnO thereupon, and polishing an uneven shape 20a transferred to the surface of the optical waveguide layer 20. Further, a reflection preventive film 21 is provided on the surface of the optical waveguide layer 20. |
