双孔径红外变焦光学系统设计

为了解决红外变焦系统短焦部分冷反射严重的问题，提出了一种双孔径设计方法，设计了一种双孔径红外变焦光学系统。系统工作波段为中波3.7 ～4.8 m，焦距为30/150/300 mm，10变倍比，具有100%冷光阑效率。对双孔径系统的短焦部分和单孔径系统短焦部分的冷反射强度进行了对比分析，双孔径系统的冷反射得到有效控制。双孔径红外变焦光学系统具有像质好、变倍比大、短焦冷反射小、结构紧凑的特点，可使大变倍比的红外变焦光学系统在红外成像系统中得到广泛应用。

Optical design of dual aperture infrared zoom optical system

In this paper, the narcissus of short focal length system was analyzed. A method of dual aperture zoom system was propounded, and a dual aperture infrared optical system was designed. The focal length of this zoom system at 3.7-4.8 m was 30 mm、150 mm and 300 mm with a zoom ranger of 10:1, F-number of 4 and 100% cold efficiency. The narcissus between dual aperture and normal single aperture was analyzed and compared,and the narcissus of dual aperture can be controlled preferably. The dual aperture zoom system has good image quality, big zoom range, low narcissus of small focal lens and compact configuration, so it can be used in the high thermal imager widely.