| 摘要 |
PURPOSE:To eliminate nearly reflected light with simple structure by arranging optical fibers which have end surfaces in planes crossing at their optical axes so that the end surfaces come into close contact with each other. CONSTITUTION:An optical fiber pad consists of a single-mode optical fiber 40 on a light emission side and a photodetection-side single-mode optical fiber 41 with specific length (l), and those optical fibers are held fixedly so that their end surfaces 40d and 41d are in an axial-shift contact state S. Both end surfaces of the cores 40a and 41a of the optical fibers 40 and 41 are separated completely from each other and arranged in contact with the end surfaces of facing clad materials 41a and 40b without any mutual coupling part. Therefore, almost all of projected light from the core 40a enters the clad material 41b and almost no light is reflected by the end surface of the clad part 41. Thus, reflected light is nearly eliminated with the simple constitution. |
