| 摘要 |
PROBLEM TO BE SOLVED: To provide an optical device which has overcome the drawbacks of a directional coupler and an MMI, being hardly caused to vary in the characteristics by dimensional accuracy, easy to manufacture, and permitting to promote miniaturization. SOLUTION: The optical device 10 has an optical multiplexing/demultiplexing function formed by placing high refractive index 1st and 2nd optical waveguides 22 and 28 side by side in a low refractive index clad layer 14. Moreover, a layer 30 is formed, which comes into contact with the parallel parts of the 1st and 2nd optical waveguides 22 and 28 and has a higher refractive index than the clad layer 14. When expressing the thickness of the part 30a of the layer 30 positioned between the 1st and 2nd optical waveguides 22 and 28 by tm1, and each thickness of the 1st and 2nd optical waveguides 22 and 28 by tc, the relation of tm1< tc is satisfied. COPYRIGHT: (C)2005,JPO&NCIPI |
