为满足光纤光栅传感技术在高真空热环境下的应用, 分析了丙烯酸酯和聚酰亚胺2种不同涂覆层单模紧套光纤作为传输光纤, 在高真空热环境下对FBG峰值功率的影响, 并进行了实验验证。首先, 设计了高真空热环境下传输光纤等效模型; 接着, 设计了不同涂覆层光纤传输损耗特性影响实验方案, 搭建了硬件在环检测平台; 最后, 进行了实验验证, 探索了在高真空热环境条件下, 不同涂覆层单模传输光纤随着温度、真空度变化对FBG反射谱功率峰值影响规律。实验结果表明: 真空度从常压降至10-4 Pa水平再恢复至常压, 丙烯酸酯和聚酰亚胺2种不同涂覆层单模传输光纤温度从常温降至-196 ℃再恢复至常温, 历经224 h, FBG反射谱功率峰值均不发生变化, 为光纤传感技术在高真空(压力约为10-4 Pa水平)、热环境(-196~25 ℃循环)中应用提供理论及实验依据。

To satisfy the application of fiber grating sensor technology in high vacuum thermal environment, FBG on two different kind of sleeve compactly single model fiber covered by acrylate and polyimide were researched. Influence of the cover on the peak wavelength power of FBG in high vacuum thermal environment was analyzed and verified. Firstly, experimental program of influence on FBG reflection spectrum characteristics was designed and then a hardware-in-the-loop detection platform was set up. Finally, the influence of temperature and vacuum on the reflection peak power of FBG in different coating single-mode transmission fiber under high vacuum thermal environment was studied and verified. Experimental results indicated that: when vacuum varied from normal pressure to 10-4 Pa level and then return to normal pressure, temperature of two different coating single-mode transmission fiber dropped to -196 ℃ from room temperature and then returned to room temperature, after 224 hours, the peak power of the FBG reflectance spectrum did not change. It provides the theoretical and experimental basis for the application of optical fiber sensing technology in high vacuum (pressure about 10-4 Pa level) and thermal environment (-196-25 ℃ temperature cycle).