Zhao Yushi, He Wenjun, Liu Zhiying, Fu Yuegang
Opt Express. 2021 Nov 22;29(24):39271-39283. doi: 10.1364/OE.444460.
With the advantages of flexible encoding and high frame rate, the digital micromirror devices (DMD) have been used as a binary encoding mask in the coded aperture snapshot spectral imaging (CASSI) systems. But the use of DMD will cause the image plane to tilt at a specific angle, so it is almost impossible to realize the strict matching between the optical system of CASSI and the cold stop of the infrared focal plane array in the mid-wave infrared band. In this paper, a CASSI system with two DMDs based on the Offner spectrometer is proposed to solve the above problem. The concept and working principle are described in detail. Under the premise of the matching optical parameters, the telescopic system, Offner spectroscopic system and microscopic system are designed independently. Then the integrated optimization design method is adopted, and the aberration of the microscopic system is used to offset the astigmatic aberration of the Offner spectroscopic system, and the imaging quality of the system is improved. The results of performance measurements confirm that the system has desirable spatial resolution and spectral response functions. Thus, the concept and optical design of the proposed system are verified to be effective and valuable.
数字微镜器件（DMD）具有灵活编码和高帧率的优点，已被用作编码孔径快照光谱成像（CASSI）系统中的二进制编码掩膜。但使用DMD会导致像平面以特定角度倾斜，因此在中波红外波段几乎无法实现CASSI光学系统与红外焦平面阵列冷光阑之间的严格匹配。本文提出一种基于Offner光谱仪的双DMD的CASSI系统来解决上述问题。详细描述了该系统的概念和工作原理。在光学参数匹配的前提下，分别设计了望远系统、Offner光谱系统和显微系统。然后采用综合优化设计方法，利用显微系统的像差抵消Offner光谱系统的像散像差，提高了系统的成像质量。性能测试结果证实该系统具有理想的空间分辨率和光谱响应函数。因此，所提系统的概念和光学设计被验证是有效且有价值的。
