一种光纤Bragg光栅波长位移的计算方法

A Calculating Method for Obtaining the Wavelength Shift of Fiber Bragg Grating

提出了一种计算光纤Bragg光栅（FBG）温度和应变传感系统波长位移的方法。该方法选取特征点来计算FBG波长位移量，与通常采用的基于FBG光功率峰值检测法相比，能够有效地提高系统的传感精度和抗扰动性能。实验表明，采用该方法，当扫描步长在5～85pm时，测量到外界扰动对应的应变的标准差小于3με。因此，这种方法放宽了扫描步长要求，降低了实验成本。

A calculating method used in optical fiber Bragg grating（FBG） temeprature and strain sensing systems is presented. The wavelength shift is calculated by choosing the characteristic point in this method. Compared with the traditional method based on optical FBG peak power detection, this method is less influenced by the ambient disturbance and able to improve the sensing accuracy. Experiments show that the standard deviation of the measured strain is less than 3 με when the wavelength scanning step is changed from 5 pm to 85 pm. As a result,this method is cost-effective as the requirement on wavelength scanning step can be relaxed.