| 摘要 |
PROBLEM TO BE SOLVED: To solve the problem that an optical circuit becomes large in a conventional waveguide type grating consisting of a plurality of first two-dimensional waveguides having an input end, a plurality of second two-dimensional waveguides having an output end, and a plurality of three-dimensional waveguides which connect the first two-dimensional waveguides and the second two-dimensional waveguides and which have wavelength dependent angular dispersion because the three-dimensional waveguide is arrayed in a horseshoe shape to make an optical path length different. SOLUTION: The three-dimensional waveguide is disposed almost linearly between a connection end with the first two-dimensional waveguide and a connection end with the second two-dimensional waveguide. At least one phase controlling element is provided on the optical path of the three-dimensional waveguide to cause an arbitrary phase difference between each three-dimensional waveguide in the emission part of the three-dimensional waveguide. |
