| 摘要 |
PROBLEM TO BE SOLVED: To provide an optical multiplexing and demultiplexing circuit in which a desired branching ratio is obtained with a large branching angle, manufacturing is made easy and fluctuation in excessive loss is suppressed. SOLUTION: An optical waveguide 16 is provided with a first waveguide 22 which communicates with an optical input output section 20 and has a first refractive index, and a second optical waveguide 24 which has a second refractive index that is greater than the first refractive index. A portion 24a of the waveguide 24 overlaps with the waveguide 22. The portion 24a of the waveguide 24 is in contact with and overlaps with the bottom surface of the waveguide 22. The side surfaces of the portion 24a which overlap the waveguide 22 are made into a tapered shape and a tip section 24d that includes a tip 24c of the waveguide 24 (a starting tip for demultiplexing and an ending tip for multiplexing) is made into a sharp shape. COPYRIGHT: (C)2004,JPO&NCIPI |
