Abstract. A temperature-compensated optical fiber twist sensor based on cascaded long-period fiber gratings (LPFG) and fiber Bragg grating (FBG) is proposed and experimentally demonstrated. The LPFG is sensitive to twist and its transmitted light is twist modulated and reflected by the FBG. In this way, a single-ended twist sensor is realized by monitoring the reflection spectrum of the cascade grating. Both the wavelength and amplitude of the reflection spectrum are detected. The wavelength is sensitive to temperature but not to twist, so it is used for temperature compensation in twist measurement. Experimental results show that the proposed sensor improves the twist accuracy by 2 orders of magnitude in the temperature range of 15°C to 35°C.

中文翻译：

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基于级联光纤光栅的温度补偿单端扭转传感器

摘要。提出并实验证明了一种基于级联长周期光纤光栅 (LPFG) 和光纤布拉格光栅 (FBG) 的温度补偿光纤扭曲传感器。LPFG 对扭曲很敏感，它的透射光被扭曲调制并被 FBG 反射。这样，通过监测级联光栅的反射光谱，实现了单端扭曲传感器。检测反射光谱的波长和幅度。波长对温度敏感但对扭曲不敏感，因此用于扭曲测量中的温度补偿。实验结果表明，所提出的传感器在 15°C 至 35°C 的温度范围内将扭曲精度提高了 2 个数量级。