锥形光纤光栅传感特性研究

Sensing characteristics of tapered fiber grating

对锥形光纤光栅(TFG)的传感特性进行了理论分析,基于传输矩阵法分析了应力与温度对不同锥角TFG反射谱特性的影响.研究表明随着应力的增大,TFG中心波长向长波长移动,反射带宽展宽。中心波长、反射带宽均与所施加的应力成线性关系.锥度越大,中心波长、反射带宽的应变灵敏度越。温度逐渐升高时中心波长向长波长移动,反射带宽不变。增大锥度,中心波长、反射带宽均不变。TFG反射带宽与温度无关,只依赖于应力大小,利用这一特性可以解决温度与应力交叉敏感的问题。

The sensing properties of tapered fiber grating （TFG） are theoretically analyzed. The influence of stress and temperature on characteristics of TFG reflection spectra of different taper angles is analyzed based on transfer matrix method. Results show that the center wavelength shifts to long wavelength and the reflection bandwidth is broadened with increasing of stress. The center wavelength and reflection bandwidth are all linear with the applied stress. The greater the taper angle is, the higher the stress sensitivity of center wavelength and reflection bandwidth will be. The center wavelength shifts to long wavelength when the temperature rises gradually, and the reflection bandwidth is constant. The center wavelength and reflection bandwidth are unchanged when the taper degree increases. The reflection bandwidth of TFG is temperature independent, and only dependent on stress, which can be used to solve the cross-sensitivity problem of temperature and stress.