为消除温度变化对共形光学导引头像质的影响, 利用光学被动消热差理论对具体设计方法进行实际分析.根据消热差条件选择合理的透镜材料组合, 利用衍射元件特殊的光热特性采用折/衍混合结构进行消热差设计.采用椭球形共形整流罩结构减小空气阻力, 降低导弹头部气动加热效应, 利用三片式反远距结构实现短焦大视场系统设计.该系统工作波段为3~5 μm, 系统F/#为2, 视场角为±90°; 凝视结构的导引头光学系统后工作距达22.8 mm, 为制冷型探测器留有足够的空间; 冷光阑效率为100%; 在-40℃~60℃温度变化范围内, 15 lp/mm处全视场MTF值均大于0.4, 满足高准确度定位导引头系统对成像质量的要求, 保证了系统的轻小型设计.

In order to stabilize the optical performance influenced by the temperature changes, an optical seeker with conformal dome on the basis of the passive optical athermallization method is discussed. Reasonable materials are chosen correctly according to athermal equations. The hybrid refractive-diffractive configuration is introduced for the design of athermal optical system design.Ellipsoidal conformal dome could optimize the aerodynamic performance and reduce the heating of the missile dome.missile dome heating. Inverted telephoto triplet is helpful to acquire short focal length and wide FOV. It is shown that an optical system with ±90° unvignetted FOR, F/2, 100% cold stop efficiency was present. A back focal length of 22.8 mm is large enough for the cooled detector, and also MTF are higher than 0.4 at the spatial frequency of 15 lp/mm across the entire field with the working wavelength at 3~5 μm. The specifications can satisfy the requirements of precise seeker, which can ensure the compact design of the system.