为获得红外目标的空间信息和光谱信息，设计了一种用于中波红外声光可调谐光谱相机的光学系统.设计中引入折/衍射混合透镜，在用6片透镜的情况下达到了12×变倍，在长焦处时能识别2 000 m远的目标.采用ZEMAX光学设计软件模拟声光晶体的衍射，在晶体出射面上优化设计了4°的楔角，使-1级衍射光能共轴出射.该光学系统在空间频率17 lp/mm处调制传递函数值最大达到0.7，能量集中度大于90%，能够满足光谱相机用于识别/跟踪目标的要求.

A medium infrared optical system was designed for acoustooptic tunable filter spectra camera to obtain the spatial information and spectral information.By introducing a hybrid refractive/diffractive lens,there are six lens in the fore zoom optical system to achieve 12× zoom ratio,which can identify the object 2 000 m far at long focal length.ZEMAX software was used to simulate the diffraction of the crystal,a wedge with 4° is needed to certify that the -1 order diffraction beams exit coaxially.Results show that the maximum modulation transfer function at spatial frequency14 lp/mm of the whole system is 0.7,the diffraction encircled energy was greater than 90%,which satisfy the image quality of the spectrum camera for target identifying and tracking.