| 摘要 |
PROBLEM TO BE SOLVED: To provide a method and a device for detecting light in an optical fiber that is not forcibly bead the optical fiber and that is easy to miniaturized. SOLUTION: Leaking light is detected via a recessed part 13 formed by deleting an optional place of a clad 12. Since light power of 10-20% exists in the boundary between a core and the clad part and the distribution of the light power in the direction from the boundary surface to the clad part is expressed by an attenuation function, light is detected via the recessed part 13 formed by deleting by, for example, several tens μm the optional place of the clad. Leaking light obtained from the optical fiber 1 is made incident on a light transmission plate 21 having a reflecting film 211, after the light is converged by a condensing lens 22, the light detecting device is composed by performing current or voltage transduction with an O/E transducer 23. |
