A Study on the Radiation-Induced Loss of Optical Fiber by ${\gamma}$-ray Irradiation

감마선 조사에 의한 광섬유의 전송손실 특성변화에 관한 연구

One of the confronting problems in using optical fibers under radiation environments is producing of color centers in optical materials due to nuclear radiation. These centers increase transmission loss by absorbing propagating light. In this study, the radiation effects on optical fiber are studied theoretically. Also, optical attenuation induced by \ulcorner-ray irradiation from Co**60 for single mode and multimode optical fibers is measured at the optical wavelength of 0.85\ulcorner and 1.3\ulcorner, and the results are analyzed. Gammaray is irradiated for 5hours at the rate of 300rads/min, which is corresponding to 90 krads of integrated dose. In case of multimode optical fibers, the induced loss at 0.85\ulcorner wavelength has been twice higher than that at 1.3\ulcorner. The loss in multimode fibers has been significantly larger by 7-20 times than that in single mode fibers, dependently on fiber materials at 1.3\ulcorner.