大孔径静态干涉光谱成像系统(LASIS)中实体Mach-Zehnder干涉仪加工误差容限分析

简要叙述了LASIS光谱成像系统的原理和仪器构成，针对LASIS光谱成像仪像方视场与干涉数据单边过零采样的要求，通过对实体Mach-Zehnder横向剪切干涉仪结构和光路进行分析，并对比Sagnac型横向剪切干涉仪的结构，研究了该干涉仪的附加光程差与加工误差的关系，给出了附加光程差公式和误差容限公式，对探测器阵面上光程差变化的非线性效应影响进行了分析和仿真。结果表明，相比Sagnac型横向剪切干涉仪，因实体Mach-Zehnder干涉仪的非共光路特点产生的附加光程差会导致探测器上的零光程位置的偏移，为保证过零单边采样的要求，需对干涉仪的尺寸误差进行严格约束，其中组成干涉仪的两块非对称五角棱镜非对称量的匹配误差小于0.02 mm;而探测器上光程差变化的非线性效应引起的光谱复原误差小于0.2%，基本可以忽略不计。

Manufacture Tolerance Analysis of Solid Mach-Zehnder Interferometer in Large Aperture Static Imaging Spectrometer (LASIS)

The principle and instrumental structure of large aperture static imaging spectrometer(LASIS) were briefly described in the present paper, the principle of the Mach-Zehnder imaging spectrometer was introduced, and the Mach-Zehnder interferometers’ working way in the imaging spectrometer was illustrated. The structure of solid Mach-Zehnder interferometer was analyzed, and discussion was made based on the requirements of field of view(FOV) in image space and single sided interferogram with a small portion around zero path difference(ZPD). The additional optical path difference (OPD) created by manufacturing and matching tolerance of two asymmetrical pentagonal prisms will lead to the displacement of shearing and OPD nonlinearity. It was showed that the additional OPD from non-common optical path structure of solid Mach-Zehnder spectrometer implies more requirements on the manufacture of this element, compared with Sagnac interferometer, for the matching tolerance of two asymmetrical pentagonal prisms to br lower than 0.02 mm. The recovery spectrum error caused by the OPD nonlinearity is lower than 0.2% and can be ignored.