Abstract The optical fiber acoustic emission (AE) sensing system with high sensitivity is stabilized for long-term detection in this paper. The high linear slope window of the phase-shifted fiber Bragg grating (PS-FBG) spectrum is tracked by the tunable laser source (TLS) to maintain high AE detection sensitivity. The experimental results show that the proposed method successfully solves the problem of PS-FBG spectrum shift caused by cross sensitivity of temperature and strain. In the high linear slope window of the spectrum, the stabilized sensing system can guarantee the AE strain sensitivity of 0.63ne/Hz1/2 at 200 kHz under the DC voltage of 10 mV. The stability of the AE sensing system is verified by stretching a carbon fibre reinforced plastic (CFRP) sample. The practical application demonstrates that the stabilized system can accurately capture the lowest order modes in the plate wave during long-term AE detection.

中文翻译：

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用于长期检测的高灵敏度光纤AE传感的稳定性

摘要 本文针对高灵敏度光纤声发射(AE)传感系统进行了稳定的长期检测。相移光纤布拉格光栅 (PS-FBG) 光谱的高线性斜率窗口由可调谐激光源 (TLS) 跟踪，以保持高 AE 检测灵敏度。实验结果表明，该方法成功地解决了由温度和应变交叉敏感引起的PS-FBG谱偏移问题。在光谱的高线性斜率窗口中，稳定传感系统在10 mV的直流电压下可以保证200 kHz时0.63ne/Hz1/2的AE应变灵敏度。通过拉伸碳纤维增强塑料 (CFRP) 样品来验证 AE 传感系统的稳定性。