大气环境下单晶蓝宝石光纤高温损伤研究

Research progress on attenuation and protection of single-crystal sapphire fiber in extreme environment

摘要:

单晶蓝宝石光纤传感器在航空航天、燃气轮机等超高温极端环境监测中扮演着重要角色。针对该类光纤在超高温环境中因高温损伤导致预期寿命的降低的难题，提出通过实验定量和系统性的评估蓝宝石光纤在高温环境下传输损耗的变化规律,测量了不同保护管、不同温度、不同波长下的光损耗数据及表面特征，发现了蓝宝石光纤高温损伤包含永久损伤和可逆损伤，永久损伤可以通过有效封装和保护极大降低。实验结果表明，在蓝宝石套管保护下，退火后的单晶蓝宝石光纤在1600 ℃时，1550 nm波段损耗速率为0.16 dB/h，为超高温光纤传感研究提供了参考。

Abstract:

Single-crystal sapphire fiber optic sensors play a critical role in monitoring ultra-high-temperature extreme environments such as aerospace and gas turbines. To address the challenge of reduced lifespan caused by high-temperature damage in such fibers under extreme thermal conditions, this study proposes an experimental and systematic quantitative evaluation of the variation patterns of sapphire fiber transmission loss in high-temperature environments. By measuring optical loss data and surface characteristics under different protective tubes, temperatures, and wavelengths, we reveal that high-temperature damage in sapphire fibers involves both permanent and reversible components. Notably, permanent damage can be substantially minimized through effective encapsulation and protection strategies. It indicates that under the protection of the sapphire tube, the loss accumulation rates at the 1550 nm wavelength for annealed single-crystal sapphire fiber is 0.16 dB/h at 1600 ℃. These findings provide valuable references for advancing ultra-high-temperature fiber sensing research.