高双折射光纤光栅扭转特性分析与应用

Analysis and Application on Characteristic of Twisted High Birefringence Fiber Grating

通过对高双折射光纤光栅的特性进行分析,提出了一种新型的可埋入工程材料的扭转传感器结构。基于光纤光栅的模耦合理论和高双折射光纤的扭转特性,建立了扭转高双折射光纤光栅传输光波的数学模型,并分析其光谱特性,仿真结果表明扭转高双折射光纤光栅的反射谱不具备方向性,只与扭转角度大小有关。当扭转角度从0变化到360°时,高双折射光纤光栅的2个主峰波长都随之产生漂移,x方向的光向短波长方向移动,y方向的光向长波长方向移动,并且反射谱峰值逐渐减小,通过前向耦合模理论与反向耦合模理论结合分析并仿真,得出x和y方向上波峰值变化量,以及相应的中心波长的变化量,最后通过实验数据对高双折射光纤光栅的变化参数与扭转角度的关系作出验证。

Through analysis on the characteristic of twisted high birefringence fiber grating, a novel torsion sensor which can be embeded in the engineering material is proposed. Based on the coupled mode theory and thecharacteristic of twisted high birefringence fiber, the mathematical model of twisted high birefringence fiber grating transmission light is established and the spectral characteristics is analyzed, the simulation results show that the reflective spectra of twisted high birefringence fiber grating does not have the direction, and is only related to the torsion angle size.When the twist angle changes from 0 to 360°, the two peak wavelength of high birefringence fiber grating are resulting in drift, light of x direction moved to the short wavelength direction, light of y direction moved towards long wavelength, and the reflection spectrum peak decreases gradually, through combining the prior to the coupled mode theory with the reverse coupled mode theory, analyzing and simulating,the conclusion that x and y directions wave peak variation are drew, and the center wavelength changes corresponding amount, finally make a validated through experimental data of the relationship between changes of parameters of high birefringence fiber grating and torsional angle.