20倍双组联动变焦距光学系统设计

Design of 20× Double-Linkage Continuous Zoom Optical System

针对双组联动变焦距系统结构复杂的特点,对其设计过程进行了梳理。在此基础上编制了可视化辅助设计软件,该软件具有高斯解计算、变倍补偿曲线绘制、像差与外形尺寸分析、相对孔径图输出等功能。使用该软件可以方便地完成双组联动变焦系统高斯解的合理选择,并给出各组元承担相对孔径及其变化情况,辅助进行初始结构的确定。利用该辅助设计软件,对一套焦距25~500 mm的20倍可见光波段双组联动连续变焦距系统进行了初始结构设计,并通过整体优化使系统像差得到校正。设计结果系统光学总长478 mm,各焦距位置在50 lp/mm处轴上视场调制传递函数（MTF）大于0.6,边缘视场MTF大于0.4,各项指标满足系统要求。

For the complexity of double-linkage zoom system, the design process is settled first, and the visible assist design software is developed. The function of the software includes Guassian optical calculation, compensation curve drawing, aberration and lens size analysis, relative aperture curve output, etc. Using the software, rational Guassian parameters can be selected conveniently, and the relative aperture and its variation of each group can be given, which can help the designer to select the initial configuration. Then utilizing the software, the initial design can performed for a double-linkage zoom system with focal length range from 25mm to 500mm. And through integrated optimization, the system aberration is corrected and balanced. The design results demonstrate that the total optical length is 478 mm, and the modulation transfer function （MTF） at 50 lp/mm for each zoom configuration is higher than 0.6 for center field, and higher than 0.4 for edge field. All indexes satisfy the command of system.