错位结构全光纤扭转传感器的研究

All-Fiber Twist Sensor Based on a Lateral Offset Structure

全光纤干涉仪具有结构简单、制作方便且灵敏度高的特点,近年来已广泛应用于各种传感领域。提出了一种基于多模光纤错位熔接于两单模光纤之间的全光纤干涉仪,并将其应用于矢量扭转测量。实验证明,若以强度解调,传感器在顺时针及逆时针扭转时的灵敏度分别为-0.225 dB/(°·m)和0.148 dB/(°·m);若以波长解调,传感器在顺时针及逆时针扭转时的灵敏度则为-0.259 nm/(°·m)和0.222 nm/(°·m)。不管采用哪种解调方法,传感器在0~180°范围内的线性拟合度都大于97%。提出的全光纤扭转传感器结构简单且性能良好,可以用于建筑形貌及结构健康监控等工程应用。提出的全光纤干涉仪在未来还可用于其他领域的传感测量,如温度、曲率等。

Because of advantages such as simple structure,ease of manufacture and high sensitivity,all-fiber interferometer has been applied in many sensing fields in recent years.In this paper,an all-fiber interferometer is proposed,which is based on a multimode fiber spliced between two single mode fibers with a certain of transverse offset.And it is applied for twist sensing.Experimental results show that the sensitivities are,through intensity interrogation method,-0.225 dB/(°·m)and 0.148 d B/(°·m)for measuring twist in clockwise and anti-clockwise directions,respectively.The sensitivities are,through wavelength interrogation method,-0.259 nm/(°·m)and 0.222 nm/(°·m)in twist directions of clockwise and anti-clockwise,respectively.The linearity,either using intensity or wavelength interrogations,is higher than97%for the twist measurement from 0 to 180°.The proposed twist sensor has advantages of simple structure and good performance,making it a good choice for engineering applications,such as shape sensing and structural health monitoring.Furthermore,it can also be used for other measurements like temperatureand curvature.