双视场折/衍混合中波红外变焦系统

Infrared dual-FOV refractive/diffractive hybrid zoom system

传统的红外变焦系统结构通常比较复杂,因此限制了红外变焦系统的应用范围。通过将二元光学元件引入红外变焦系统中达到了简化系统结构的目的,并给出了具体的设计实例及衍射元件进行公差分析。系统采用透镜4片构成,有效焦距为92 mm,F数为1时与有效焦距276 mm,F数为2时,在17 lp/mm的传递函数值均接近衍射极限。设计结果表明,在传统折射系统中引入二元光学元件,可简化系统、改善相质。

Traditional infrared zoom system structure is often complex, thus the application of infrared zoom system is limited. To achieve the purpose of simplifying the system structure, binary optical elements was introduced in infrared zoom system. Design example which had four lens and tolerance analysis of binary optical element were given. In small field of view, the effective focal length was 276mm, F number was 2; in large field of view, effective focal length was 92 mm, F number was 1. In both fields of view, the value of MTF in 17 lp/mm is close to the diffraction limit. The results show that by using BOE, the structure of system is simplified, the image quality is improved.