| 摘要 |
PROBLEM TO BE SOLVED: To facilitate the manufacture by providing a specific waveguide branch which is so arrayed as to receive a light energy output by an active waveguide part with a specific refractive index. SOLUTION: A switch 26 has a 1st waveguide part 34, intermediate waveguide parts 36 and 38 and an active core 32, and branch waveguide parts 40 and 42 which are assembled by a substantially similar method. The intermediate waveguides 36 and 38 have length L2 and include a part 44 between them, and is in a triangular shape as a nearly gradual decrease shape related to a 1st gradual decrease angleΘ1 of about 1.8 deg.. Namely, rays which are parallel to a relative trapezoidal surface form the 1st gradual decrease angleΘ1 at their intersection. The respective branch waveguide parts 40 and 42 are almost straight and have a 2nd gradual decrease angleθ2 of each 0.2 deg. related to length L3. Namely, the rays which are parallel to the relative surfaces of the branch waveguide parts 40 and 41 form the 2nd angleΘ2 at their intersection. The branch waveguide parts 40 and 42 are so coupled as to functionally operated on intermediate parts 36 and 38. |
