Fabry-Perot (F-P) filter based fiber Bragg grating (FBG) demodulation has been widely applied in many areas. However, the F-P filter suffers from random fluctuation in wavelength scanning when the ambient temperature changes severely, which reduces the demodulation accuracy inevitably. In this paper, a demodulation method based on an etalon and a fiber-optic Michelson interferometer is proposed to improve the demodulation accuracy in an environment with variable temperature. The experiment is carried out by constructing an interferometer with long-optical path difference (OPD). When the environment temperature increases from 20 °C to 60 °C in 30 minutes, the results show that the error of the proposed method is reduced from ± 20.39 pm to ± 6.89 pm. The standard deviation is 3.11 pm, which is reduced by 43.92% compared with the etalon-based demodulation method.

中文翻译：

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变温环境下光纤布拉格光栅解调长OPD干涉仪波长扫描非线性校正

基于法布里-珀罗 (FP) 滤波器的光纤布拉格光栅 (FBG) 解调已广泛应用于许多领域。然而，当环境温度剧烈变化时，FP滤波器会出现波长扫描的随机波动，不可避免地降低了解调精度。本文提出了一种基于标准具和光纤迈克尔逊干涉仪的解调方法，以提高变温环境下的解调精度。实验是通过构建具有长光程差（OPD）的干涉仪来进行的。当环境温度在 30 分钟内从 20°C 升高到 60°C 时，结果表明该方法的误差从±20.39 pm 降低到±6.89 pm。标准偏差为 3.11 pm，减少了 43。