类椭圆结构光纤横向压力传感器及其温度自补偿研究

Elliptical optical fiber transverse load sensor and its temperature self-compensation research

为解决光纤横向压力传感器灵敏度不高及温度交叉敏感的问题,提出了一种具有温度自补偿的类椭圆结构光纤横向压力传感器。传感器通过将标准单模光纤(single mode fiber, SMF)弯曲成类椭圆结构,并用聚二甲基硅氧烷(polydimethylsiloxane, PDMS)封装形成,温度自补偿则通过将另一个近似孪生的类椭圆结构与测量端并联实现。类椭圆弯曲下SMF的纤芯模和包层模发生干涉,其干涉光谱随外界横向压力的变化发生漂移。实验结果表明,在0.25—0.5 N的横向压力范围内,传感器的特征波长随横向压力的变化呈线性关系,在33.5—44℃的温度范围内,温度自补偿后的灵敏度可达6.6 nm/N,温度交叉灵敏度仅为0.001 5 N/℃,温度补偿误差不超过0.089 nm。提出的横向压力传感器灵敏度高、成本低、结构简单,有一定的应用参考价值。

To solve the problem of low sensitivity and temperature cross-sensitivity of optical fiber transverse load sensor,an elliptical structure optical fiber transverse load sensor with temperature self-compensation is proposed.The sensor is formed by bending a standard single mode fiber(SMF)into an elliptical structure and encapsulated in polydimethylsiloxane(PDMS).The temperature self-compensation is realized by paralleling another nearly twin elliptical structure of the measuring element.The core mode and cladding mode interfere in the elliptical bending SMF,and the interference spectrum shifts with the change of applied transverse load.The experimental results show that the characteristic wavelengths of the sensor have a linear relationship to the transverse load in the range of 0.25-0.5 N.In the temperature range of 33.544 C,the sensitivity after temperature self-compensation can reach 6.6 nm/N,the temperature cross sensitivity is only 0.0015 N/C,and the temperature self-compensation error is less than O.089 nm.The proposed transverse load sensor has high sensitivity,low cost and simple structure.It has certain application reference value.