| 摘要 |
<p>An optical waveguide substrate 14 is provided with a branch-type optical waveguide 17 which includes a stem portion 17a and a plurality of branch portions 17d each provided between one end face 14a and the other end face 14b of the substrate 14. Optical fibers 3A, 3B and 3C respectively corresponding to the stem portion 17a and the branch portions 17d are held by the optical fiber holding substrate 7. The optical fibers are respectively coupled with the corresponding stem portion and the plural branch portions at end faces thereof. The optical waveguide substrate 14 is provided with a reflecting means 18 on or in a vicinity of the other end face 14b and the reflecting means reflects light propagated through the stem portion and transmits the reflected light towards the branch portion. Light transmission loss caused by a large change of the ambient temperature may be thereby avoided or considerably reduced. <IMAGE></p> |
