| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To provide an optical fiber and an optical coupler which can suppress degradation in the coupling efficiency when a core diameter is enlarged to thereby provide high coupling efficiency and, at the same time, can solve a problem of adverse effect on a human body due to emission light. <P>SOLUTION: Single-mode optical fiber parts 14, 24 and core-enlargement optical fiber parts 13, 23 which constitute optical fibers 201, 202 are each SI-type optical fibers each consisting of a core and a clad. The core-enlargement optical fiber parts 13, 23 are respectively fusion-spliced with the single-mode optical fiber parts 14, 24 with the edge surfaces of the fine diameter side inside. Phase adjusters 15, 25 are respectively disposed outside the core-enlargement optical fiber parts 13, 23. The optical coupler 301 is constituted of the core-enlargement optical fiber parts 13, 23 and the phase adjusters 15, 25, and the phase adjusters 15, 25 are arranged opposite to each other while being abutted on each other or being separated from each other by a prescribed distance, whereby the optical coupling is performed. <P>COPYRIGHT: (C)2008,JPO&INPIT</p> |
