一种高精度光纤Bragg光栅传感器解调方法研究

Research on high precision demodulation method of fiber Bragg grating sensor

为了提高光纤Bragg光栅(FBG)解调系统的波长解调精度,满足实际中高精度测量的需要,提出基于F-P可调谐滤波器和波长基准器,采用相关谱法和线性插值法相结合的处理技术。该方法不但可以有效地抑制噪声,而且,可以精确地检测波长漂移量。实验表明:采用此方法可使Bragg光栅波长分辨力和解调精度相对于传统的峰值检测法有很大提高,波长分辨力达到1 pm,温度测量精度达到±0.2℃。

In order to improve wavelength demodulation precision of fiber Bragg grating （FBG） demodulation system and satisfy the need of high precision measurement practically, based on F-P tunable filter and wavelength standard device, a processing technique that combines correlation spectrum method with linear interpolation method is presented. This method not only can restrain noise effectively, but can detect wavelength drift quantity accurately. Experiments indicate that wavelength resolution of Bragg grating and demodulation precision both can be improved well compared with conventional peak detection method, and wavelength resolution is lpm, temperature measureing precision is ±0.2 ℃.