| 摘要 |
PURPOSE:To decrease an increase of a transmission loss of an optical fiber, by using an optical signal conforming with the minimum loss wavelength, for the optical fiber receiving the irradiation of a radiant ray, and also making intense light having a photo-bleeding effect incident into the optical fiber at all times. CONSTITUTION:An optical signal conforming the minimum loss wavelength is sent to an optical fiber 14 receiving the irradiation of a radiant ray, through an electric signal transmitter 7 and an electric/optical transducer (E/O)8. Its optical signal is reflected by an optical branching device 10 of a receiving part 13. On the other hand, intense light having a photo-bleeding effect is made to transmit the optical branching device from an E/O12 of the receiving part 13, and is sent to the optical fiber 14. Accordingly, an increase of a transmission loss caused by generation of the color center by irradiation of a radiant ray of the optical fiber 14 is decreased. |
