| 摘要 |
PROBLEM TO BE SOLVED: To reduce dispersion of a loss between output channel wave guide passages by enabling plural output channel wave guide passages to have an output loss set according to a wave branching loss respectively suffered by the plural pieces of signal light. SOLUTION: Output channel wave guide passages 71 to 7N are arranged in a radial shape with a point O3 in the central vicinity of a connecting surface 6A of an output side slab wave guide passage 6 as the center. The signal light L1 to LN of wave lengthsλ1 toλN incident from a connecting surface 6B of the output side slab wave guide passage 6, are branched and emitted, and are made incident on corresponding optical fibers 111 to 11N. A taper part 9 is formed on the output side of the output channel wave guide passage 71 . A core width of the taper part 9 becomes larger in order as it proceeds to the output channel wave guide passage 71 arranged outside from the line symmetry axial L of the output side slab wave guide passage 6. A connecting loss of a connecting part of the optical fiber 111 of the output channel wave guide passage 71 decreases as the core width of the taper part 9 becomes larger. |
