基于多级微镜的傅里叶变换成像光谱仪干涉成像系统分析与设计

为了实现傅里叶变换成像光谱仪的静态化与高通量，提出一种基于多级微镜的时空混合调制成像光谱仪，其干涉系统是利用一个多级微镜代替迈克尔逊干涉仪中的平面镜，其显著特点是无运动部件和限制系统光通量的狭缝，可同时获得目标的干涉图与二维空间图像。该成像光谱仪利用前置成像系统将目标成像到干涉系统的平面镜与多级微镜上，利用多级微镜的结构特点对两成像光束的光程差进行调制，然后通过后置成像系统获得不同干涉级次的目标图像。首先通过对该成像光谱仪干涉系统光谱信噪比的分析，明确了光谱信噪比与图像信噪比之间的关系，确定了多级微镜的特征参数。为了确保每个阶梯面所对应光程差的恒定性，通过对前置成像系统成像过程的分析，确定了前置成像系统像方远心的光路结构;通过对系统视场角与光程差之间关系的分析和计算，确定了前置成像系统的设计指标并完成了光学设计。为了保证后置成像系统不引入额外的光程差，通过对后置成像系统成像特点的分析，确定了后置成像系统双远心的光路结构;通过对系统入射孔径角与阶梯级数之间关系的分析和计算，最终设计出满足系统性能需求的后置成像系统。通过对各单元系统的理论分析与光学设计，为静态化与高通量成像光谱仪的发展提供了一种新的思路。

Analysis and Design of Interference Imaging System in Fourier Transform Imaging Spectrometer Based on Multi-Micro-Mirror

To realize the static state and high throughput of Fourier transform imaging spectrometer (FTIS),a temporal spatial mixed modulated FTIS based on multi-micro-mirror was put forward in this paper,whose interference system was based on Michelson interferometer with a multi-micro-mirror to replace the plane mirror.The remarkable characteristics of this FTIS were no movable parts and slit existing in this system,and the interferogram and image of obj ect could be gained at the same time. The fore-optics system imaged the obj ect on the plane mirror and multi-micro-mirror of the interference system,due to the struc-ture feature of multi-micro-mirror,the optical path difference (OPD)of two imaging beam could be modulated.Through the re-imaging system,the image of obj ect with different interference order could be obtained.By means of the analysis to the spectrum signal-to-noise ratio (SNR)of interference system,the relationship between spectrum SNR and image SNR was definite,and the characteristic parameters of multi-micro-mirror were determined.To ensure the constancy of OPD corresponding to each step plane,by means of the analysis to the imaging process of fore-optics system,the optical path structure of telecentric in image space was determined.According to the calculation of the relationship between field of view and OPD,the design indexes of fore-optics system were determined and the optical design was completed.To ensure no extra OPD was introduced by reimaging sys-tem,through the analysis of the imaging feature by reimaging system,the optical path structure of double telecentric was deter-mined.According to the calculation of the relationship between incidence aperture angle and step number,the optical system that satisfied the system requirement was designed.By means of the theory analysis and optical design to each unit system,this re-search can provide a novel development strategy for static and high throughput FTIS.