2008 年 74 巻 1 号 p. 57-61
The fusion splicing of ribbon-shaped eight optical fibers was carried out with CO2 laser beams. At first, laser beam of uniform power distribution, which was obtained by simple aperture method, was irradiated to every fiber. However, defective connections were frequently occurred at both edges of the ribbon fibers, because the heat inputs to these fibers were low and not enough to melt silica glass fibers. Two-dimensional heat conduction analysis indicated that the reason was the large heat transfer and radiation from these fibers to atmosphere. Therefore, higher laser power was necessary to be supplied to two edge fibers. Laser beams designed specially, which had about 20∼22 % higher power density at edge region, enabled the temperatures of all fibers to reach their softening point simultaneously. As a result, excellent connections with low splicing loss of 0.011dB on average values were achieved.