弹光调制干涉仪稳定控制及快速光谱重建方法研究

The photo-elastic modulation Fourier transform spectrometer (PEM-FTS) with high speed, wide spectrum and high sensitivity is the spectral analysis apparatus, which has extensive application in the near infrared transient spectral detecting fields. As its core unit the photo-elastic modulation interferometer, its modulated frequency is high, its resonant frequency has performance of thermal drift and its modulated optical path difference is nonlinear. In order to the high-speed and accurate rebuilding and recognition of the spectrum, In the project, based on multi-physical field coupling theory, the characteristic impedance of PEM is studied, the thermal drift model of its resonant frequency is built, the relationship between the maximum optical path difference of photo-elastic modulation interferograms and vary of resonant frequency is analyzed. The adaptive driving method of mult-parameter broadband matching PEM is put forward, on account of the adaptive frequency tracking theory, the measuring method of the maximum optical path difference and its steady control model. According to mass data and the phase nonlinearity of the photo-elastic modulation interference signals, Large amount of data processing method and the nonuniform fast Fourier transform algorithm are studied, and the interferogram preprocessing theory, calibration and adjustment method of the rebuilding spectrum, the fast and accurate spectral rebuilding algorithm is put forward. The stability control and fast spectral rebuilding system of PEM-FTs is set up to verify the performance of the system and to measure the error. The project is contribute to the real-time detection and identification of the high-speed transient spectrum.

弹光调制傅里叶变换光谱仪（PEM-FTs）是一种高速、宽光谱、高灵敏度的光谱分析仪器，其在近红外瞬态光谱探测领域具有广泛的应用价值。但弹光调制干涉仪作为其核心部件，其谐振频率高、具有温漂特性，调制光程差呈非线性。为了实现快速准确的光谱重建和识别，本课题基于多物理场耦合理论，研究弹光调制器的阻抗特性，建立其谐振频率温漂模型，分析弹光调制干涉图最大光程差与谐振频率漂移之间的关系；基于自适应频率跟踪技术、最大光程差检测方法以及光程差稳定控制模型，提出多参数宽带匹配型PEM自适应驱动控制方法；研究大数据云处理方法和快速准确的非均匀快速傅里叶变换(NUFFT)算法，结合干涉信号预处理理论、重建光谱的标定和校准理论，提出快速准确的光谱重建算法；基于搭建的PEM-FTs的稳定控制及光谱重建平台，实现快速光谱重建和误差分析。该项目的研究有助于高速、瞬态光谱的实时探测和识别。

弹光调制干涉仪因其谐振频率高、稳定性差、光程差非线性，使得PEM-FTs的稳定驱动控制技术、快速光谱重建技术存在技术难题。本课题对弹光调制干涉仪的工作机理进行了分析，针对弹光调制器热耗散和频率漂移比较严重，建立了其温度频率漂移模型；设计了多参数宽度匹配自适应驱动控制系统，实现了驱动频率的自跟踪和幅值的自调节，提高了重建光谱的稳定性；针对干涉图不对称问题，将Mertz法进行改进，并与NUFFT算法进行结合，实现了快速、较准确的光谱重建；鉴于晶体的折射率随波长变化，对以参考激光测量的最大光程差进行了多次校正，实现了重建光谱的准确标定；基于所设计的驱动控制系统和数据处理平台，搭建了弹光调制傅里叶变换光谱仪的稳定控制及光谱重建平台，验证了该系统的稳定性和重建光谱的准确性。本项目为弹光调制傅里叶变换光谱仪的研究，奠定了理论基础和实践经验。通过本项目的研究，发表学术论文11篇，其中SCI收录4篇，EI收录4篇；授权国家发明专利4项；培养博硕士研究生7人。