射频光纤链路γ射线辐致损伤特性实验研究

The radiation impairing property by γ ray on radio over fiber link

由于空间环境中宇宙辐射无处不在,工作在空间环境的光纤系统必须考虑辐致损伤特性。建立了10GHz的射频光纤链路传输系统,分别采用单模光纤和保偏光纤作为传输媒质。利用60 Co`γ射线源,在剂量率1rad/s总剂量50krad下,对射频光纤链路进行辐照实验,对两种系统做对比分析。实验结果表明,单模光纤链路的辐致损耗绝对值较大,保偏光纤链路的辐致损耗绝对值较小;单模光纤的幂律模型指数较保偏光纤大,即同样的辐照剂量,单模光纤受影响程度大。在辐照起主要影响因素的阶段,单模光纤延时差受辐照影响程度较保偏光纤稍小。辐致损耗和辐致延时差对光纤长度都有线性累加作用。从整体水平看,50krad的辐射总剂量对两种光纤造成的损伤并不大,传输的信号仍在可用的范围之内。

Because of space radiation in space flight environment, the fiber system in there must be considered about radiation harming property. Radio frequency （RF） fiber system for 10GHz is set up, which employ both a single mode fi- ber （SMF） and a polarization maintain fiber （PM：F） as communication media, respectively. Utilizing ^60COγ source, in the condition of dose rate lrad/s and total rate 50krad, the radiation experimentation is made for RF fiber link and the both system with SMF and PMF are compared in aspect of radiation property. The experiment results indicate that the SMF link＇s loss by radiation is larger than the PMF link＇s; the power law model exponent of the SMF link is a little larger than that of the PMF link, that is, the radiation impact on SMF is greater than that of PMF under the same radiation con- dition. In the phase of main impacting factor from radiation, the time delay and refraction index of SMF is less than that of the PMF due to radiation; the forward link＇ s is less than the backward link＇ s coming from radiation impact. In a whole, the impact of both kinds of fibers by radiation is not large under total dose 50krad, and the＇ communication signal is still useful.