倾斜少模光纤光栅扭转传感研究

Research on tilted few-mode fiber Bragg grating twist sensor

提出了一种基于倾斜少模光纤光栅的扭转传感结构,分析了传感基本原理,并对其传感特性进行了实验研究。通过实验得出,具有倾斜光栅的少模光纤比普通少模光纤对扭转的传感效应更加明显。测量并分析比较了多组不同倾斜角度的倾斜少模光纤光栅的扭转传感效应,发现当光纤光栅的倾斜角度为1°时,其扭转传感效应最佳。该基于倾斜少模光纤光栅的扭转传感,结构简单、灵敏度高、易与被测物集成,且在扭转角度为0°^-180°范围内光强差的变化与扭转角度几乎呈线性变化。

In this paper, a twist sensor structure based on tilted fiber Bragg grating （TFBG） in few-mode fiber has been proposed. The basic principle of the twist sensor has been discussed and its sensing characteristics have been demonstrated. It is experimentally confirmed that few-mode fiber with TFBG used as twist sensoris much more sensitive than common few-mode fiber. The twisting sensibility of several sets of few-mode TFBG with different tilted angle has been measured and analyzed. It was found the one with titled angle of I degree isthe most sensitive. The proposed twist sensor based on few-mode TFBG has simple structure, high sensitivity and is easy to be integrated with the measured object. Moreover, the light intensity difference is almost linearly changed with the twist angle when the twist angle ranges from 0° to 180° .