Effect of Steady-state and Transient γ Radiation on Ge-doped Quartz Optical Fiber

Ge-doped quartz optical fibers were irradiated by steady-state γ with dose rate of 1.0×10^-4-0.5 Gy(Si)/s and transient γ with dose rate of 10⁶-10⁹ Gy(Si)/s. The results show that the radiation induced loss in optical fiber satisfies saturate exponential relationship with total dose, which agrees with the conclusion developed from color center concentration differential equation. The radiation induced loss in optical fiber increases with dose rate at a given total dose. The photobleaching effect was validated by the result that radiation induced loss in optical fiber is less with transmitted light during irradiation. The radiation induced loss in optical fiber decreases with increasing wavelength from 650 to 1310 nm. The transient radiation induced loss in optical fiber is much larger than steady-state radiation induced loss. The peak magnitude of transient radiation induced loss in optical fiber is linear with pulse total dose, which agrees with Taylor expansions approximation of saturate exponential relationship at low total dose.