| 摘要 |
<p>PROBLEM TO BE SOLVED: To provide a directional coupler which can be integrated in a stacking direction and a device for optical communication which uses it. SOLUTION: The directional coupler 100 includes a substrate 10, a 1st waveguide layer 31, a 2nd waveguide layer 32 arranged on the 1st waveguide layer 31, and separation layers 41 and 42 which separate at least one end part of each of the 1st and 2nd waveguide layers 31 and 32, which have an optical coupling part 50 where they come close to or in contact with each other in a specific region and are both formed integrally or continuously. Further, a 1st clad layer 21 which is arranged on the substrate and has a projection part to the substrate 10 and a 2nd clad layer 22 which is arranged on the 2nd waveguide layer 32 are included and a part of the 1st waveguide layer 31 is arranged on the projection part of the 1st clad layer 21 to constitute the optical coupling part 50.</p> |
