We compared the degradation of two kinds of 1550nm single-mode optical fibers following the irradiation by gamma ray (<sup>60</sup>Co). Over a total dose of 9.06×10<sup>4</sup> rad, the absorption coefficient increased while the rates were different between samples. The influence of ionizing radiation is theoretically analyzed. In room temperature annealing experiment, the absorption coefficient of Corning sample was recovered visibly, but Alcatel sample continues to deteriorate. It is suggested that different producing technology and doping are clearly influence the generation and recombination process of color center.
We investigate the sensitivity of fiber amplifiers to radiations and present an approach to design radiation hardened
rare-earth doped fiber amplifiers. This paper includes testing experiments on comparing the radiation responses (200krad
electron irradiation) of fiber amplifiers made with same lengths of different rare-earth doped fibers. Simulation tools can
also be used to improve the tolerance of the fiber amplifiers by helping identifying the best performance for operation in
harsh environment, simulation analysis figured that fiber length of the amplifier should be optimized to reduce the
radiation-induced losses around the signal wavelength that strongly impact the fiber response. By using this particular
approach, fiber amplifiers with little insensitivity to radiations could be manufactured in the future.