弹载卡式红外光学系统消热差设计

为了消除环境温度变化对弹载红外光学系统成像质量的影响，设计了一种在3.7 m~4.8 m波段工作的弹载卡塞格林式红外消热差光学系统。利用ANSYS软件分析了整流罩在大气中的受热变形对光学系统成像质量的影响，采用光学被动式消热差法对光学系统在-40℃~+65℃范围内进行了温度补偿。设计结果表明，系统MTF在20 lp/mm时轴外可达0.41以上，不同视场下的弥散斑直径小于一个像元尺寸且系统结构简单。该设计可保证光学系统的像面稳定性，有效提高火控系统对目标探测与识别能力。

Athermalisation of infrared Cassegrain optical system in missile

In order to eliminate the ambient temperature effect on the performance of infrared optical system in missile, an athermal infrared Cassegrain optical system was designed for 3.7 μm~4.8 μm band. The ANSYS software was used to analyze the effect of heated dome deformation on imaging quality of infrared system. Optical passive athermalisation technique was a proper choice, which could achieve the compensation for ambient temperature in the range of -40 ℃~+65 ℃. The results showed that the off-axis of MTF was greater than 0.41 at 20 lp/mm, the dispersion spot diameter was less than one pixel in different views and the structure of optical system was simple. This design ensured the stability of the optical system imaging plane and effectively improved the ability of detecting and recognizing targets for fire control system.