| 摘要 |
PROBLEM TO BE SOLVED: To obtain a smart-loss optical branching and coupling unit by obtaining a specific branching ratio by adjusting both the length of an abutting area and the angle of the area of a plastic fiber extending from the abutting area to the length direction of the abutting area at the same time. SOLUTION: Two plastic fibers or more are prepared and made to abut on each other to predetermined length, and they are fused and bonded by ultrasonic excitation in the abutting area. At this time, a branching ratio 1:1 is obtained by adjusting both the length of the abutting area and the angle of the area of the plastic fiber extending from the abutting area to the length direction of the abutting area at the same time. Namely, the black dots and white dots in the Fig. show the upper limit and lower limit of fiber angles θsuitable for the branching ratio 1:1. Further, the straight line LL shows the relation between the length of a branching and coupling part and the lower limit value θL of the suitable fiber angles θ. The straight line LU, on the other hand, shows the relation between the length of the branching and coupling part and the upper limit value θU of the suitable fiber angles θ. |
