光学温度补偿红外长波远摄型物镜设计

环境温度变化导致红外光学系统成像质量变差,利用光学材料热特性之间存在的差异,研究了一种光学温度补偿红外长波远摄型物镜设计方法。首先,根据远摄物镜基本结构及远摄比建立含参方程;其次,结合不同材料组合及消热差和消色差方程将前组复杂化,获得初始的光焦度分配。最后,利用ZEMAX光学设计软件进行优化、像差校正,设计实例焦距为100 mm,F数为2.0,远摄比达到0.8,全视场角6°。设计结果在-40℃~60℃范围内,成像质量稳定,焦距变化量小于系统最小焦深,成像质量接近衍射极限。

Design of Long-wavelength Infrared Telephoto Objective with Optical Temperature Compensation

The degradation of imaging quality of an infrared optical system is caused by the changing of envi- ronment temperature. Based on the differences in optical material thermal characteristics, a design method of long-wavelength infrared telephoto objective with optical temperature compensation is researched. Firstly, equa- tions containing parameters are established according to the basic structure of telephoto objective and telephoto ratio. And then, the former group is complicated with different material combinations and the equations of athermal and achromatic to obtain initial optical power distribution. Finally, ZEMAX optical design software is used to opti- mize and correct aberration. Parameters of the design example are obtained such as 100 mm focal length, 2.0 F number, 0.8 telephoto ratio and 6° field of view （FOV）. The result shows that the system has stable imaging quality in -40-60 ℃ operation temperature range, focal length and imaging quality approaches diffraction limit. variation is less than minimum depth of focus of the system.