摘要:
通过对该系统采集到的法布里-珀罗(F-P)标准具透射谱和光纤布拉格光栅(FBG)传感器反射谱进行寻峰算法以及拟合算法的研究,采用C语言编程和LabVIEW编程相结合的方式,实现了FBG波长信号的解调。其中,由于系统采集到的F-P透射谱和FBG反射谱线时域信号数据都由离散点构成, 且在3 dB带宽内均符合高斯曲线分布,采用高斯拟合对采集到的信号数据进行寻峰处理,提高系统精度;又由于分布式反馈(DFB)激光器的波长扫描存在着一定的非线性,采用二项式拟合对DFB激光器的波长扫描曲线进行拟合,以降低其非线性导致的误差。另外,设置一路标准FBG传感通道用于波长校准。实验研究表明该系统稳定性良好,波长测量范围为1 550.012~1 554.812 nm,分辨力为1 pm,精度为10 pm,验证了该系统可用于FBG波长信号检测的可行性。
Abstract:
Through the study of the demodulation algorithm including the searching peak algorithm and fitting algorithm on the collected data (the domain signals of the Fabry-Perot (F-P) etalon transmission spectrum and fiber Bragg grating (FBG) sensors reflection spectrum) by the system, the FBG wavelength signal demodulation is achieved by way of combining C language programming with LabVIEW. As the collected data points consisted of the time-domain signals of F-P etalon transmission spectrum and FBG reflection spectrum by the system are discrete, and within 3 dB bandwidth the time-domain signal spectra of F-P etalon and FBG are in line with a Gaussian curve distribution, the Gaussian fitting is used for the collected data points to find the time point corresponding to the signal peak to improve system precision; Also, because of the certain nonlinearity of the distributed feedback laser (DFB) laser scanning wavelength with the scanning time, the binomial curve fitting is used to reduce the error caused by the nonlinearity. In addition, a standard FBG sensing channel is set for wavelength calibration. Experimental studies show that the system has a good stability, the wavelength measurement range is 1 550.012-1 554.812 nm, the resolution is 1 pm, the precision is 10 pm, verifying the feasibility of the system applying to the FBG wavelength signal detection.
点击查看大图
下载:
