选用适当的全景环形镜头模型,运用CODE-V软件设计了一款小型紧凑结构红外全景镜头。设计结果表明,选用的全景环形镜头模型有利于镜头的小型化和集成化,将模型的两个透射面和两个反射面全部设置为球面,降低了镜头加工的难度,通过优化相对孔径,提高了系统的灵敏度和分辨率。中继系统采用三片式结构,其中非球面和衍射面的运用有效地平衡了系统像差。最终得到的镜头工作在3-5 μm波段,对±55°-±100°视场成像,F数为1.3,有效焦距为-0.53 mm,总长为64.5 mm,最小分辨极限只有6.3 μm。 CODE-V软件分析显示,系统横向像差在-0.021-0.021 mm之间,为艾里斑直径的1.6倍,调制传递函数(MTF)值在空间分辨频率为40 lp/mm时大于0.2,成像质量良好。

Through choosing panoramic annular lens model and using CODE-V,a new small infrared panoramic lens with compact structure is completed. The result indicates that panoramic annular lens model is conducive to miniaturization and integration of the lens,and the difficulty of lens′s processing is reduced by setting the model′s two transmission surfaces and two reflection surfaces to sphere,and the optimizing of the relative aperture can improve system′s sensitivity and resolution. The system aberrations are effectively balanced by setting asphere and the diffraction surface in relay system. The lens has a waveband 3-5 μm,a field of view ±55°-±100°,F-number of 1.3,effective focal length of -0.53 mm,overall length of 64.5 mm,and the resolution limit of the lens is only 6.3 μm. The analysis of the CODE-V software demonstrats that the lateral aberration of the system is between -0.021-0.021 mm,only 1.6 times the diameter of the Airy spot,and the value of the modulation transfer function (MTF) is greater than 0.2 at 40 lp/mm,and the lens has a good imaging quality.