| 摘要 |
PROBLEM TO BE SOLVED: To inexpensively provide an optical waveguide type wavelength filter with desired filter characteristics.SOLUTION: The optical waveguide type wavelength filter 2 includes: a linear waveguide core 3 like a straight line, which transmits light; a lower annular waveguide core 4 in the shape of a ring, which is formed on the same surface as that of the linear waveguide core 3; and an upper annular waveguide core 5 in the same shape as that of the lower annular waveguide core 4 and formed on the lower annular waveguide core 4. |
