| 摘要 |
PROBLEM TO BE SOLVED: To provide an optical device whose cost and size are reduced and which is used as an optical demultiplexer and an optical multiplexer. SOLUTION: An optical device 1 is provided with two optical waveguides 3 and 4 formed on the surface of a substrate 2. The device 1 is provided with a directional coupler 5 formed by making the waveguides 3 and 4 close to each other. The waveguides 3 and 4 are respectively provided with cores 21 and 22 and clads. The shapes of the cross sections of the cores 21 and 22 are made into mutually different squares and the refractive indexes are also mutually made different. |
