| 摘要 |
PROBLEM TO BE SOLVED: To provide a tapered waveguide by which the mode of a fiber is matched with the mode of the waveguide so as to accomplish low loss connection efficiently. SOLUTION: In a first technique, a fixed gap taper, in which the length of a gap is substantially fixed as to each segment 108 and the length of a core part, is continuously reduced from the end part, on a waveguide path side to the end part on a fiber side of a taper for expanding a mode, is accomplished. In addition, according to a second technique, a side gap taper, in which a side gap containing a gap material is used for increasing a mode size in the taper, is accomplished. |
