| 摘要 |
PROBLEM TO BE SOLVED: To manufacture a polarization maintaining optical fiber coupler whose excess loss is small. SOLUTION: The manufacturing method of the fiber coupler includes a step of placing two polarization maintaining optical fibers in parallel and a part of the fibers is heated and drawn longitudinally to form a welded and drawn part. After or simultaneous with the manufacturing method includes this forming process, an adjusting step in which a desired coupling characteristic is obtained in the range of wavelengths in use, and in which the cycle of fluctuation in the degree of coupling and that in the excess loss are adjusted so that the excess loss is minimized. Thus, the polarization maintaining optical fiber coupler is manufactured. |
