介绍了一种用于非制冷凝视焦平面探测器的长波红外双视场光学系统设计实例，该系统工作波段为8～12μm，变倍比为2.5倍，采用轴向移动变焦方式。引入一个衍射光学元件，减少了光学零件的数量，减轻了系统质量，具有成像质量高、体积小、重量轻等优点，并用ZEMAX光学设计软件进行了像质评价。

A dual field-of-view optical system with uncooled infrared staring focal plane arrays is designed in this paper. The operating waveband of the system is 8-12 μm, and zoom ratio is 2.5^×. The optical configuration is based on the axial motion of a lens group along the optical axis. A diffractive optical element is used in the system to reduce optical element number, light its weight, and have the advantages of better image quality, small size and light weight. The optical system image quality is evaluated with the ZEMAX optical design software.