为实现光纤传感器的波长解调,以8通道50 GHz密集型波分复用器作为光纤光栅压力传感器中的解调工具,依据各个通道的中心波长作为波长的标定基准,利用从各通道中获得的光功率输出值获得光纤光栅反射光谱分布曲线的包络,并以高斯多项式拟合法作为光纤光栅波长寻峰算法,最终获得光纤光栅反射光谱的中心波长的准确位置,从而实现结构简洁、成本低廉、全光纤的波长解调系统,系统压力与波长的线性拟合度为0.996 5,实验测得的波长分辨率可达0.3 pm,最大引用误差为2.6%,测量精度为0.16 MPa。

In order to realize the wavelength demodulation of the optical fiber sensor, a 8 channel 50 GHz dense wavelength division multiplexer was used as the demodulation tool of the fiber Bragg grating pressure sensor. Taking the center wavelength of each channel as the calibration standard, the optical power output obtained from each channel was utilized to acquire the envelope of the distribution curve of the fiber grating reflection spectrum. By using the Gauss polynomial fitting method as peak-seek algorithm of fiber grating wavelength, the accurate position of the center wavelength of the fiber grating reflection spectrum was obtained and a simple structure, low cost, all-fiber wavelength demodulation system was achieved. The experimental results show that the linear fitting degree of the system pressure and wavelength is 0.996 5, the measured wavelength resolution is 0.3 pm, the maximum reference error is 2.6%, and the measurement accuracy is 0.16 MPa.