用时延估计法提高光纤光栅中心波长检测精度  

Improvement of Measurement Accuracy in Fiber Bragg Grating Sensors by Using Time Delay Estimation Techniques

作　　者：吴艳群[1] 胡永明[1] 姜暖[1] 杨华勇[1] 

机构地区：[1]国防科学技术大学光电科学与工程学院,湖南长沙410073

出　　处：《光学学报》2009年第9期2447-2451,共5页Acta Optica Sinica

基　　金：国家自然科学基金(60507010)资助课题

摘　　要：提出将雷达、声呐领域中的时延估计算法用于均匀应变场或温度场中任意形状的光栅反射谱中心波长的检测。分析了信噪比(SNR)对不同形状反射谱进行峰值提取的影响。分析结果表明,对均匀周期的单模光纤布拉格光栅,其长度越长,折射率变化越大,峰值检测受信噪比影响也越严重;实验结果表明,与常规算法相比,采用时延估计中的相位谱法进行中心波长偏移量的提取,估计精度不受波长扫描精度的限制,对噪声造成的中心波长随机漂移有很好的抑制作用,而且无需对反射谱的形状进行假设与曲线拟合,计算量小,检测精度可达到皮米量级。The Phase-spectrum method （PS）, widely used in time delay estimation techniques in the fields of radar and sonar, is applied to detect the wavelength shift for any shape of reflection or transmission spectrum of fiber Bragg grating sensors in homogeneous strain or temperature fields. The peak detection sensitivity to noise is analyzed, and the results show that for single mode FBG sensors, the larger the fiber length and the refractive index is, the more seriously the SNR influences on the peak detection. The experimental results show that compared with conventional algorithms, the proposed method can effectively suppress the random excursion of the central wavelength, and its estimation accuracy is not limited by the wavelength accuracy. Besides, it needs no assumption of the spectrum shapes and no interpolations, and thus reduces the computational consumption. The wavelength detection accuracy is on a scale of pm.

关 键 词：光纤光栅 波长检测 峰值提取 时延估计 相位谱法 

分 类 号：TN253[电子电信—物理电子学]