长焦距大口径连续变焦距光学系统

为了实现对远距离目标的实时跟踪与测量，设计了口径为650 mm，焦距为5 000~2 000 mm的连续变焦距光学系统。提出了牛顿式折反射光学系统与倒置的连续变焦距光学系统组合的设计方法，实现了光瞳的合理匹配与对接。确定了合适的入瞳位置，消除了变焦过程中像面容易产生的鬼像。通过合理匹配主系统和变焦距系统的光焦度，使得二级光谱最小化。运用CODEⅤ软件对各焦距位置的像差进行优化与平衡，使变焦距光学系统在各焦距位置的像差均得到校正与平衡，像面保持严格的一致性，从而各焦距位置成像质量良好。实验显示该系统全视场平均传递函数均在0.524以上（Nyquist频率：35 lp/mm），满足使用要求。

Optical zoom system with long focal length and large aperture

To accomplish the real-time track and measurement of remote distance objects, a continuous zoom optical system with an aperture of 650 mm and the long focuses of 5 000-2 000 mm was designed. The combinatorial design method of a Newton catadioptric system and a reverse continuous zoom system was adopted, and the pupil was matched and connected reasonably. A proper pupil position was determined, then, the ghost often appeared in the image plane in zoom process was eliminated. By reasonable matching the focal power of the main system and the zoom system, the secondary spectrum was minimized. By using the CODE Ⅴ software to optimize and balance the aberration of every focal length, all the aberration of focal positions in the zoom optical system were corrected and balanced, and the image plane was consistency strictly. Thus, the imaging quality of each focus is favorable. Experiments show that the full field average Modulation Transfer Function(MTF) of each focus at the Nyquist frequency is over than 0.524, which meets the system requirements.