将衍射面和塑料非球面元件引入到传统的Petzval 型球面系统中，设计了含有1 个衍射面和1个塑料非球面元件的5 片单管双目式微光夜视物镜，并分析了塑料元件的热效应影响,计算了衍射面的加工工艺参数。该物镜具有长焦距、大相对孔径、小畸变的特点；在物距L＝∞和L＝10m、空间频率为40 lp/mm 时，轴上传递函数≥0.70，轴外传递函数≥0.50，全视场畸变≤0.40%；光学总长由传统物镜系统的128 mm 缩短为110 mm，重量仅为190 g，减少为传统物镜的62.5%，适用于夜间瞄准与测量。

The diffractive surfaces and plastic aspherical elements are introduced into the design of conventional Petzval spherical system. A five-element objective of single tube binocular containing a diffractive surface and a plastic asperical surface is designed. The thermal effects of the plastic elements are analyzed. The manufacturing parameters of the diffractive surface are calculated. The objective has a long focal length, large relative aperture, small distortion. When the object distance is infinity or 10m, and the spatial frequency is 40 lp/mm, the on-axis MTF is not less than 0.70 and off-axis MTF is not less than 0.50. The distortion of TFOV is less than 0.40%. Compared with a conventional spherical objective with equivalent performance, the total track of the optical system reduces from 128 mm to 110 mm, and the weight reduces to 62.5% of the conventional objective, i.e. 190 g. This objective is suitable for accurately measuring and aiming during nighttime.