Investigation on irradiated characteristics of Tm-doped gain fiber

We demonstrated a stable fiber laser setup for real-time monitoring of Tm-doped gain fibers while being exposed to gamma-rays. The output power is about 10W, and the power stability of the system is ±0.25% based on the 12-hour continuous measurement. By using this laser setup and 60Co gamma-ray irradiation source, the dose rate effect and total dose effect on the typical Tm-doped fiber specimens under water-cooling condition were experimentally studied. According to the obtained experimental results on five kinds of Tm-doped gain fiber from different R and D institutions and batches at home and abroad, the output power declines monotonously with the total irradiation dose increasing. During a dose rate range of 0.05 to 0.5 rad(Si)/s, the dose rate effects of Tm-doped gain fiber samples basically disappear, which means the differences of power degradation under different dose rate are almost invisible.