| 摘要 |
PROBLEM TO BE SOLVED: To provide an array waveguide type diffraction grating in which adjacent cross talk is reduced and it is made suitable for wavelength divided multiplexed transmission. SOLUTION: The followings are formed on a substrate 1, i.e., optical input waveguides 2, a first slab waveguide 3, array waveguides 4 in which a plurality of channel waveguides 4a having mutually different lengths that are beforehand set is arranged in parallel, a second slab waveguide 5 and a waveguide forming section 10 in which optical output waveguides 6 are successively connected in parallel. The number of the waveguides 4a is set so that the optoelectric field distribution, which propagates in the waveguides 4, is matched with the distribution made up by a main beam and the whole or a portion of the first side-lobes located on the both end sides of the main beam. |
