| 摘要 |
PURPOSE:To raise the degree of freedom of a branching ratio by adjusting an angle of a branch slit and enlarging a branch angle. CONSTITUTION:An optical waveguide 1 consists of a core 3 and a clad 4 for covering it, and is constituted on a plane substrate 2 so that its cross section is roughly rectangular. The core 3 is constituted of a branch line 3A being an incident part, and branch lines 3B and 3C being emitting parts. On the way of the optical waveguide 1, a branch slit 5 formed by having an inclination of an angle theta1 against the branch lines 3A, 3B is provided. By the angle theta1 made by the branch lines 3A, 3B and the branch slit 5, and an angle theta2, a branch angle of the waveguide type optical branch unit is determined. The branch slit 5 consists of a structure cut in the height direction to the halfway of the core 3, in a branch part 6. This connected part L1 of the optical waveguide 1, and the part L2 which is connected without being cut exist, and by an area ratio (area ratio of the branch slit) of these L1 and L2, a branching ratio of light in this branch waveguide is determined. |
