基于游标效应解调的少模光纤应变传感器

Few-mode Fiber Strain Sensor Based on Vernier Effect Demodulation

摘要:

提出并制备了一种基于游标效应的高灵敏度光纤马赫-曾德尔应变传感器。该传感器由两个自由光谱范围相近的马赫-曾德尔干涉仪并联构成。其中单个马赫-曾德尔干涉仪是由一段无芯光纤和一段少模光纤拼接在两根单模光纤之间制成的。两个马赫-曾德尔干涉仪的自由光谱范围相近而不相等,并联叠加后产生游标效应,达到增敏的效果。实验结果表明,在0~166.667με的应变范围内,单个干涉仪的应变灵敏度为-1.90pm/με,两个干涉仪并联叠加谱包络的应变灵敏度为12.06pm/με。该传感系统采用并联方式实现游标效应,具有制作简单、灵活性高、灵敏度高等优点,可广泛应用于精密测量领域。

Abstract:

A highly sensitive fiber optic Mach-Zehnder strain sensor based on vernier effect was proposed and prepared. The sensor consisted of two Mach-Zehnder interferometers with similar free spectral ranges connected in parallel. The single Mach-Zehnder interferometer was made by splicing a section of no-core fiber and a section of few-mode fiber between two single-mode fibers. Two Mach-Zehnder interferometers with similar but unequal free spectral ranges were superimposed in parallel to produce the vernier effect to achieve the effect of increased sensitivity. The experimental results show that the strain sensitivity of the single interferometer is -1.90pm/με in the strain range of 0~166.667με, and the strain sensitivity of the envelope of the superimposed spectrum of two interferometers in parallel is 12.06pm/με in the strain range of 0~166.667με. This sensing system adopts parallel connection to realize the vernier effect, which has the advantages of simple fabrication, high flexibility and high sensitivity, and can be widely used in the field of precision measurement.