【摘要】 利用一对固定Bragg波长的光栅作为参考,在锯齿波电压驱动下,可调谐滤波器输出的窄带光分别扫描传感光栅和参考光栅,使用高斯寻峰算法计算出参考光栅反射峰值波长对应的驱动电压。在参考波长区间,利用参考光栅的波长准确性高的特点,对滤波器输出波长进行校准,建立滤波器调谐波长与扫描电压的关系。传感光栅的Bragg波长可以通过线性插值求取。温度传感实验中,利用质心法、微分法和高斯拟合法计算光栅反射峰值波长,分别获得±1℃、±0.5℃和±0.3℃测量精度,对应着±10pm、±5pm和±3pm的波长误差。实验结果表明,波长校准和选择好的寻峰算法分别减小了可调谐滤波器波长输出非线性性及波长扫描精度低带来的测量误差。更多还原

【Abstract】 Two Fiber Bragg Grating (FBG) sensors with fixed Bragg wavelength were used as reference. The narrow band light from tunable filter driven by saw waveform voltage scanned sensing FBG and reference FBG respectively. Driving voltage corresponding to reflected peak wavelength of reference FBG can be calculated by employing Gaussian peak-seek algorithm. In the given reference wavelength range, wavelength of the tunable filter was calibrated by reference wavelength with high accuracy, and the relationship between the wavelength and the driving voltage was constructed, and Bragg wavelength of sensing FBG can be obtained with the linear interpolation method. In temperature sensing experiment, the temperature measurement precisions of ±1℃, ±0.5℃ and ±0.3 ℃ are achieved by applying Centroid method, differential method and Gaussian-fit method to calculate peak position. Corresponding wavelength error is ±10pm, ±5pm and ±3pm respectively. The experiment results show that wavelength calibration and good Gaussian peak-seek algorithm reduce the wavelength measurement error caused by wavelength nonlinearity of tunable filter and low scanning wavelength resolution.更多还原