伽马辐照对掺镱光纤材料特性影响的研究

Effect of gamma irradiation on characteristics of Yb-doped fiber materials

掺镱光纤是高功率激光器的核心材料,但在高能射线辐照后其应用性能会显著下降,因此有必要对掺镱光纤材料在辐照环境下的性能变化进行深入研究。采用改进型化学气相沉积法结合稀土螯合物掺杂制备了系列光纤预制棒及光纤,测试了光纤在不同剂量下射线辐照前后的高功率输出性能,以及光纤预制棒辐照前后的吸收光谱及镱离子荧光寿命。结果表明:小剂量辐照后掺镱光纤的高功率输出显著下降,通过预制棒吸收光谱可看出主要是因为伽马辐照后使掺镱光纤材料中Al的相关缺陷浓度增多,在可见光区域吸收损耗增加。Ce离子的掺杂通过缓减辐致铝氧空位中心(Al-OHC)色心缺陷的增加,减少Yb离子荧光寿命的下降,可在一定程度上抑制高功率掺镱光纤的辐致暗化。

Yb-doped fibers are the key materials in high power lasers, its application performance will significantly decrease after irradiation with high-energy rays. Therefore, it is necessary to conduct in-depth research on the performance changes of Yb-doped fiber materials under irradiation. A series of optical fiber preforms and optical fibers were prepared by modified chemical vapor deposition combined with rare-earth chelate-doping method. The high-power output performance of the optical fibers and the optical properties of preforms before and after irradiation were studied. The experimental results show that the high-power output of Yb-doped fiber significantly decreased after low-dose irradiation. It can be seen from the absorption spectra that the main reason is that after irradiation, the Alrelated defect concentration in the Yb-doped fiber materials increases, and the absorption loss in the visible region increases. Ce ions doping can reduce the increase of Al-oxygen hole centers(Al-OHCs) color center defects caused by radiation, reduce the decrease of Yb ions fluorescence lifetime, and suppress the radiation darkening of Yb-doped fibers to a certain extent.