| 摘要 |
PROBLEM TO BE SOLVED: To optimize the trade-off between the channel bandwidth and crosstalk attenuation by adjusting the sizes of an input and an output waveguide mode field. SOLUTION: A planar optical circuit 10 is formed on a substrate 12 of silica, etc. Two remaining layers are layers formed out of a core material 14 and a clad material 16 and are different in refractive index. Input and output waveguides 20 and 22 are placed on a Rowland circle regarding a diffraction grating 24 so that a mode field at the internal end part 28 of the input waveguide 20 is converged on various internal ends 30 of the output waveguide 22 according to respective wavelengths of light of an image, and channel wavelength is selected according to the position of the internal end 30 of the output waveguide 22. To generate channels at constant wavelength intervals, the internal end 30 of the output waveguide 22 should be put at intervals equal to the Rowland circle where the light is converged. |
