时空调制型干涉成像光谱仪的强光干扰效应仿真研究

干涉成像光谱技术是利用光的干涉原理获取目标光谱信息的一种成像技术。为研究其在强光下的干扰效果和机理,以大孔径静态成像光谱仪为典型对象,开展了相关仿真实验研究。以实际地物的图像和光谱信息为对象,仿真生成了原始干涉成像图案,并模拟830 nm单波长激光和超连续谱激光两种干扰源,分别研究不同辐照强度下的典型干扰效果,分析时假设光谱角大于30°时原始光谱信息丢失。基于本文的仿真模型,得到的相关结果表明,在830 nm的单波长激光干扰情况下,当干扰与目标成像峰值之比大于0.2∶1时原始光谱信息无法正确复原（光谱角大于30°）,但模拟加入830 nm滤光片后,干扰效果被有效滤除。在超连续谱激光干扰情况下,不考虑饱和阈值时光谱角数值最终稳定在21°;考虑探测器饱和阈值为目标成像强度峰值3倍时,干扰与目标成像峰值之比大于2.1∶1时,原始光谱信息便无法分辨。该研究可能为同类型光谱仪的激光辐照效应和损伤机理的后续研究,以及光谱成像系统的激光防护和性能优化提供参考。

Simulation study of strong light interference effect in temporally and spatially modulated Fourier transform imaging spectrometer

This paper presents the computational studies on the effect and mechanism of strong light interference in the large aperture static interference imaging spectrometer. First, we generated images with simplified ground targets and computed the corresponding original interference imaging pattern. Then, we simulated a 830 nm single-wavelength laser and a super continuum laser respectively, to analyze the typical interference effects. During the process, it was assumed that the original spectral information could be resolved only when the spectral angle is lower than 30°. For the 830 nm laser interference, the spectral angle would reach 30° when the ratio of laser interference imaging peak to the target imaging peak was 0.2∶1, but the interference effect could be effectively filtered by the 830 nm filter. In the case of super continuum laser interference, the spectral angle was finally stabilized at 21° without considering the saturation threshold, but the detector could be oversaturated more easily. Overall, both 830 nm laser and super continuum laser can disable the spectrum recovery process, but the mechanisms are different since the former one shifts the characteristic peak of the spectrum and the latter makes the interference fringes unrecognizable.