使用背照减薄型CCD的色散型超光谱成像光谱仪中近红外波段干涉条纹现象的研究与校正

摘要

使用背照减薄型CCD器件的色散型超光谱成像光谱仪在近红外波段会出现条带状干涉条纹，严重影响其在近红外波段附近的光谱分辨率。为解决该现象，建立了类似于法布里-珀罗干涉仪的多光束干涉模型，估算出700～900 nm范围内干涉条纹的强度分布并以实测数据对该模型进行了验证，分析了CCD光敏区厚度和干涉现象之间的关系。在此基础上，采用包括频域滤波在内的改进的平场校正算法，对干涉条纹的图像进行了校正，在751.83～1010.04 nm的范围内，校正效率达到96.6％，试验结果表明，该算法可有效的消除超光谱成像光谱仪近红外波段上的干涉条纹现象，提高光谱分辨率。%Dispersive hyperspectral imaging spectrometer using back-illuminated CCDs will cause interference fringes in near-in-frared band ,reducing the near-infrared spectral resolution .To solve this problem ,we established a multi-beam interference model similar to a Farby-Pérot interferometer ,estimated the intensity of distribution of interference fringes from 700 to 900 nm , verified its correctness with measured data ,and analyzed the relationship between CCD photosensitive zone thickness and the in-terference phenomenon .On this base ,the authors used the improved flat-field correction algorithm to correct the interference . From 751.83 to 1 010.04 nm wavelength ,the correction efficiency can reach 96.6% .The results show that the algorithm can effectively eliminate the interference of dispersive hyperspectral imaging spectrometer in near-infrared band .