| 摘要 |
PROBLEM TO BE SOLVED: To greatly reduce manufacturing cost of a polarization coupling/ branching coupler and to enable an expensive polarization plane maintaining optical fiber to be reused for manufacturing even if its thermal melt-sticking is failed. SOLUTION: Using two optical fibers (2, 3) which are formed by splicing the polarization plane maintaining optical fiber (4) and a single-mode optical fiber (5) in the middle (2M, 3M), thermal melt-sticking is performed on that middle part (2M, 3M). |
