变间隙法布里-珀罗干涉仪光程差线性分析

对于变间隙法布里-珀罗（F-P）干涉式成像光谱仪，空间干涉信息是否按光程差等间隔采样，即光程差与探测器像元位置之间是否是线性变化关系，直接决定了光谱数据处理的难易程度。经分析，变间隙法布里-珀罗干涉式光谱成像系统的光程差是干涉仪分光产生的两艾里斑的中心距离的函数，而两艾里斑中心距与探测器像元位置并非一直保持线性关系，与干涉仪楔角的取值有关。研究了不同楔角条件下光程差与探测器像元位置之间的关系曲线，结果表明，在任意楔角下，光程差与探测器阵列像元位置之间均保持良好的线性关系。长波红外变间隙F-P干涉式光谱成像系统与高精度光谱辐射计测得的特征峰位置重合度达100%。

Linear analysis of optical path difference of variable-gap Fabry-Perot interferometer

For the variable-gap Fabry-Perot (F-P) interferometric imaging spectrometer, whether the spatial interference information is sampled at equal intervals of optical path difference (OPD), that is, whether the relationship between optical path difference and detector pixel position is linear, directly determines the difficulty of spectral data processing . After analysis, the OPD of the variable-gap F-P interferometric imaging system was the function of the centre distance of two Airy disks produced by the beam split of the interferometer. However, the centre distance of two Airy disks did not always maintain a linear relationship with the detector pixel position, which was related to the value of the wedge angle of the interferometer. The relationship between optical path difference and detector pixel position under different wedge angle conditions was studied. The results show that there is a good linear relationship between optical path difference and detector array pixel position at any wedge angle, and the position contact ratio of characteristic peak measured by long wave infrared spectral imaging system with variable-gap F-P interference and spectral radiometer with high precision reaches to 100%.