| 摘要 |
PROBLEM TO BE SOLVED: To provide an optical coupler with a filter which is suitable and easy for manufacturing by fitting the filter to a multicore type coupler in particular. SOLUTION: The optical coupler connects optical signals propagating in a plurality of optical transmission lines in which a slit 21, which is tilted by a specified angle with respect to the disposing direction of the respective optical waveguides, is cut, a filter 4, which is to be inserted into the part of the optical waveguides at which the filter is placed, is inserted into the slit 21 formed by being cut and the angleθof the filter 4 and the slit 21 is formed in at least approximately 8 degree in order to prevent a reflection from the filter 4. |
