基于双层衍射元件的红外双波段光学系统设计

摘要

利用红外双波段成像能够获得更多的信息,从而提高探测和识别能力.将多层衍射光学元件应用到红外双波段光学系统中,可以校正色差、简化结构.讨论了多层衍射光学元件的成像特性,相比于单层衍射光学元件,多层衍射光学元件可在宽波段范围内获得高衍射效率,给出了多层衍射光学元件设计方法.基于此,设计了一种红外双波段混合成像光学系统.其中,双层衍射光学元件在3.7～4.8 μm和7.7～9.5 μm工作波段上的衍射效率述98.5％以上.仿真结果表明,系统像质良好,满足要求.%The detection and recognition capability can be improved by using infrared dual-band imaging to obtain more information.The application of multi-layer Diffractive Optical Elements (DOEs) in infrared dual-band optical system can correct the chromatic aberration and simplify the system structure.Compared with the single-layer DOEs,the multi-layer DOEs have higher diffraction efficiency in wide wave bandwidths.In this paper,the imaging characteristics of multi-layer DOEs are presented,and the design method is given.Based on which,an infrared dual-band hybrid diffractive-refractive optical system is designed.The diffraction efficiency of the double-layer DOE is higher than 98.5％ in the working bands of 3.7 to 4.8 μm and 7.7 to 9.5 μm.The simulation result shows that the system has fine imaging quality,and the performance meets the optical system requirements.