折反式周视红外成像系统光学设计

Design of Catadioptric IR Panoramic Imaging Optical System

为增大周视成像系统视场的同时有效降低红外光学系统的复杂度,采用折反式光学结构,通过反射镜及透镜光焦度的合理分配,引入衍射面。分别设计了视场为360°×(--40°～50°)的折反式一次成像非制冷红外周视成像光学系统及视场为360°×(--30°～50°)的折反式二次成像光学系统。其工作波段为8～12■m,光学系统F数为1.2。该系统可实现360°全方位和一定俯仰角度范围内凝视成像。设计结果表明,该系统的结构简单紧凑,后截距大,成像良好,在空间频率20 1p/mm处的调制传递函数(Modulated Transfer Function, MTF)值大于0.4,能满足应用需求。

To reduce the complexity of the infrared optical system effectively while increasing the field of view of a panoramic imaging system,a catadioptric optical structure is used and a diffractive surface is introduced through reasonable rationing of the mirror and lens focal power.A catadioptric once-imaging uncooled infrared panoramic imaging optical system with the field of view up to 360°×(from-40°to 50°)and a catadioptric secondary imaging uncooled infrared panoramic imaging system with the field of view up to 360°×(from-30°to 50°)are designed respectively.The imaging system operates in the waveband from 8 μm to 12 μm and its F number is 1.2.It can implement staring imaging at a certain pitch angle in a 360-degree viewing range.The design results show that the system is simple and compact in structure,large in posterior intercept and good in imaging quality.Its modulation transfer function value at the special frequency of 20 lp/mm is greater than 0.4,which can meet the application requirements.