| 摘要 |
PROBLEM TO BE SOLVED: To reduce the connection loss of a connection between the core of an optical waveguide and a circular or elliptical optical waveguide layer. SOLUTION: A lower cladding layer 18 provided on a substrate 12 has a valley-shaped hollow 38 along a groove 36 on its surface, by providing the groove 36 on the surface of the substrate 12 of an optical waveguide 28. Furthermore, the core in provided along the valley-shaped hollow 38 and then the core lower part (part of core 22 facing lower clad layer 18) is a curved surface on which the shape of the hollow is reflected. Consequently, the connection loss due to the difference in shape between the core 22 of the optical waveguide 28 and the circular or elliptical optical waveguide layer connected to the optical waveguide 28 is reduced. When an optical fiber 48 is connected, the groove 36 is usable as an optical fiber mount groove, thus the core 22 of the optical waveguide 28 and the core 50 of the optical fiber 48 are positioned self-alignedly to reduce the connection loss. |
