通过对基于多级微反射镜的空间调制傅里叶变换红外光谱仪准直误差的分析, 模拟了准直误差的存在而导致的干涉图大光程差处对比度反转和光谱图边频噪声的产生。 讨论了在不同的误差系数下复原光谱图的信噪比和分辨率, 并且分析了干涉图大光程差处对比反转以及光谱图边频分量的产生原因。 仿真结果表明, 在误差系数α＝0.15°·mm-1时, 光谱的信噪比会下降到6 dB, 同时光谱分辨率会退化到13.4 cm-1。 本文的结论将应用于微型光谱仪系统的光学设计与装调。

The collimation error in Fourier transform spectrometer has many effects on the interferogram and the spectrogram. By means of modulation, the authors found the reverse of contrast in the interferogram and the side slope noise in the spectrogram due to the collimation error. The authors analyzed the signal-to-noise ratio and resolution at different factor of beam divergence. When the factor of the beam divergence is 0.15°·mm-1, the signal-to-noise ratio can reduce to 6 dB and the resolution can go bad to 13.4 cm-1.