高清晰大变倍比中波红外连续变焦光学系统设计

随着红外热成像系统的不断发展，对红外光学系统也提出了更高的要求。为了满足红外探测器在军事方面的广泛应用，整机系统对高性能、大变倍的红外连续变焦光学系统的需求日益增强。针对高端中波制冷型640512 凝视焦平面探测器，设计了结构紧凑、性能优良的高清晰大变倍比机械补偿连续变焦光学系统。该系统工作波段为3.7耀4.8m，F 数为4，变倍比为35:1，变焦范围为15~550mm。该系统运用平滑换根理论，实现了超大变倍比的连续变焦光学系统设计，并且采用二次成像以及45反射镜对光路进行U 型折叠，在实现了冷屏效率100%的同时有效控制了该系统的横向和径向尺寸。采用光学设计软件CODE V 进行了仿真计算和像质评价，并绘制了该系统的变焦曲线。设计结果表明，该连续变焦光学系统具有分辨率高、变倍比大、结构紧凑、在全焦距范围内成像质量优良并且变焦轨迹平滑等优点，能够与高性能中波红外探测器匹配用于高端红外热成像系统。

High resolution middle infrared continuous zoom optical system with large zoom range

For advanced 640 512 cooled staring focal plane array (FPA) detector, a mechanical compensation continuous zoom optical system with greater than 30zoom range was presented based on the requirements of infrared thermal imager. The zoom system provided continuous changed in the field of view from the narrow field of view to the wide field of view. The largest constraint that used to exist developed a strategy that would allow the zoom focus to be continuous. The large zoom range created the condition of the zoom groups moving through the 1magnification case. Discontinuities about this 1magnification point was well documented in the paper. The spectral band of the system was 3.7-4.8 m, and F number was 4.0. It realized 15-550 mm continuous zoom with a smooth zoom path and provided high image quality within the whole zoom range. Moreover, detailed design and image quality were given by CODE V optical design software. By the virtue of secondary imaging structure and tow reflectors, it has 100% cold shield efficiency and can reduce the transverse and radial size of system. The design results prove that the zoom system has high resolution, large zoom range, small size and excellent image quality and has also been found to be capable of accommodating advanced infrared thermal imager.