| 摘要 |
PURPOSE:To constitute a small-sized optical multiplexer/demultiplexer having a high wavelength separation capability by providing plural waveguides in parallel in a second stage after providing plural waveguides in parallel in a first stage. CONSTITUTION:Light beams 14 and 15 having wavelengths lambda1 and lambda2 from a waveguide 1 are divided to waveguides 2 and 3 in accordance with wavelengths because the center wavelength in coupling between waveguides 2 and 3 and the waveguide 1 is selected to be lambda1 and lambda2. Auxiliary waveguides 4 and 5 eliminate light beams 14 and 15 having wavelengths lambda1 and lambda2 as unnecessary light from waveguides 2 and 3. That is, not only wavelength demultiplexing is performed but also a large attenuation quantity in the stop band is taken by the constitution of first-third waveguides, and unnecessary leaked light is suppressed furthermore by third and fourth waveguides. Thus, the optical multiplexer/demultiplexer having a prescribed wavelength separation capability is realized with a short element length and it is miniaturized. |
