大口径红外离轴三反光学系统设计及公差分析

在空间光学领域中，光学系统的发展趋势为长焦距、大视场、轻量化、大相对孔径、高成像质量等。为适应该发展趋势，对大口径反射式光学系统进行研究，在共轴三反系统的成像理论基础上，为避免中心遮拦，提高成像质量，采用视场离轴方式，设计了一款大口径离轴三反式光学系统。该光学系统在奈奎斯特空间频率17 lp/mm处，光学传递函数MTF大于0.75，成像质量接近衍射极限。此外，光学系统公差的合理分配是影响相机总体性能的主要因素，运用公差灵敏度分析和反转灵敏度分析，计算各公差对光学系统成像质量的影响，给出了合适的公差分配，经过模拟分析，按照给定的公差加工装调，系统光学传递函数大于0.55。

Design and tolerance analysis of infrared off-axis three-mirror optical system with large aperture

In the field of space optics, the development trend of optical systems is long focal length, large field of view, light weight, large relative aperture, high imaging quality, and so on. In order to adapt to this development trend, the large-caliber reflective optical system is studied.An off-axis three-mirror optical system with large aperture was designed based on the imaging theory of coaxial three-mirror optical system and the way of field off-axis was used to avoid central shielding problem and improve the image quality. The modulation transform function (MTF) of the optical system is more than 0.75 at the Nyquist frequency of 17 lp/mm and the image quality is close to the diffraction limits. In addition, since the tolerance reasonable distribution of optical system is the main factor that affects the performance of camera, the sensitivity analysis and the inverse sensitivity analysis were used to compute the effect of each tolerance parameter on the optical system image quality and the proper tolerance distribution was determined. Through simulation analysis, the optical system can has high image quality with fabricated and assembled on the basis of tolerance given, and the MTF can be more than 0.55.