| 摘要 |
PROBLEM TO BE SOLVED: To provide an optical star coupler and a single direction optical star coupler which are small and inexpensive by leading out input and output optical fibers from the same side with short waveguides. SOLUTION: The optical star coupler has the input optical fiber 1, the output optical fiber 3 and an input end face 2A, and output end face 2B which are joined with these optical fibers 1 and 3 to their one end side. An input optical path 2a from the input end face 2A and an output optical path 2b from the output end face 2B are turned back and connected by the other end 26. Both optical paths 2a and 2b are isolated from each other by a light reflection plate 25. The end 26 of a mixing part 2 is formed to an arcuate shape or elliptic shape and is turned back. The outer peripheral part of the end 26 described above is treated with a light diffusion body 27 of a reflection type and the inside of the optical path of the end 26 is subjected to the diffusion treatment 28 of a light transmission type or the inside of the optical path of the end 26 is subjected the treatment of either the diffusion treatment 28 of the light transmission type or the treatment with the diffusion body 27 of the reflection type including its outer periphery part as well. |
