| 摘要 |
PROBLEM TO BE SOLVED: To shorten the whole length along a first propagating direction, to improve productive efficiency and to reduce a radiation loss more than that in conventional constitution, in a wavelength demultiplexer. SOLUTION: A first boundary line F1 in a first end surface V1 exists by the distance (b) (b>0) nearer to a second end H2 than a first end H1, and moreover a second boundary line F2 in the first end surface V1 exists by the distance (b) nearer to the first end H1 than the second end H2. Also, a fourth boundary line F4 in a third end surface V3 exists by the distance (a) (a>0) nearer to a fourth end H4 than a third end H3, and moreover a sixth boundary line F6 in a fourth end surface V4 exists by the distance (a) nearer to the third end H3 than the fourth end H4. |
