线阵InGaAs扫描FBG反射谱的传感解调方法

研究并实现了一种基于256像元线阵InGaAs扫描的光纤布拉格光栅传感解调系统。针对线阵InGaAs探测器,分析了光纤光栅反射谱中心波长定位原理,可实现多个FBG光谱的同时解调,单通道解调传感器数量取决于FBG的带宽和中心波长漂移范围。对256个像素点的光谱数据,通过设置的阈值判断反射谱的个数,分别对每一个谱峰进行拟合,基于高斯指数曲线模型实现了寻峰算法,获得了中心波长。搭建FBG解调系统采集光谱数据,寻峰算法的稳定性达到0.5 pm。该解调方法无机械移动部件,实现了多光纤光栅波长寻峰的并行快速响应,波长解调范围为1 525～1 570 nm,为多光纤光栅传感提供了高速解调方案。

Demodulation method for FBG reflection spectrum based on linear array InGaAs scanning

A demodulation system based on 256 pixels linear array InGaAs detector for fiber Bragg grating sensors was researched and realized. Based on the linear array InGaAs detector, the peak positioning principle of the fiber Bragg grating reflection spectrum was put forward. This multiple FBG spectrum parallel processing could be realized. The demodulation quantity of single channel depended on the bandwidth of the FBG sensor and the center wavelength drift range. Based on the spectral data of 256 pixels, Gaussian curve model for central wavelength was adopted. By setting the threshold value, the number of reflection spectrum peak was obtained, separately for each spectrum peak fitting. The demodulation technique was proved to be highly accurate and highly stable by the experiment results. The stability of peak searching algorithm reached 0.5 pm. The demodulation method has no mechanical moving parts, which realizes the parallel processing and quick response of the fiber Bragg grating center wavelength. The wavelength demodulation range is 1 525-1 570 nm. It provides a high-speed demodulation scheme for fiber Bragg grating sensing.