| 摘要 |
PROBLEM TO BE SOLVED: To provide an optical waveguide of an element (AWG element), etc., for which array waveguide gratings provided with sufficient wavelength accuracy or reduced in element size are used by introducing a refractive index adjusting region into a coupler part. SOLUTION: When the light signal subjected to wavelength multiplexing is introduced from one among the input waveguides 2, this light is subjected to the phase shift meeting an optical path difference in the array waveguide grid part 4 and is outputted after the light is separated by each wavelength to the waveguides 6 on an output side. In such a case, a refractive index adjusting region 11 is formed in part of a star coupler 3 on an input side in order to improve the wavelength accuracy. If a difference is given to the refractive index from another region in this refractive index adjusting region 11, the bend of the optical path by a prism effect occurs in the input side star coupler 3 and the light waveguide outputted in the specific channel on the output waveguide side is eventually changed. |
