设计了一种用来校准紫外与可见光光轴平行性的可调焦光学系统, 调焦范围为70 m~∞。针对目前大多数校准系统无法进行调焦的问题, 提出一种既能校准紫外与可见光光轴平行性又能对紫外部分进行调焦的方法。采用离轴卡塞格林系统作为初始结构进行设计, 通过在传统的卡塞格林系统中加入调焦组和补偿组来实现调焦以及像差补偿, 所设计的系统可以有效地解决紫外与可见光双光轴平行性失调的校准问题, 提高紫外与可见光双光轴平行性校准效率, 并且在不同视距下光学传递函数值及点列斑均接近衍射极限, 能量集中度达到90%, 整个视场的像质均匀, 像面清晰, 有利于后续的图像处理工作。

A focusing optical system used for calibration of ultraviolet and visible light optical axis parallelism was designed with the focusing range of 70 m~∞. Aiming at most calibration systems' problems that can not focus at present, a method was put forward, which can calibrate the ultraviolet and visible light optical axis parallelism, and focus the ultraviolet part. We used the off-axis Cassegrain system as the initial structure to design, and added the focus group and compensation group into the traditional Cassegrain system so as to implement the focusing and aberration compensation. The designed system can effectively solve the calibration problems of the ultraviolet and visible light double-axis parallelism and improve the calibration efficiency. Also, the modulation transfer function (MTF) values and spot diagram both close to the diffraction limit under different object distances, moreover, the energy concentration reaches 90%, the view image quality of the entire field is even and image surface is clear, which are good for the follow-up image processing.