基于二元衍射面的长波无热化光学系统设计

仅用3片透镜,设计了一款匹配640×512氧化钒非制冷长波焦平面探测器的红外系统。该系统焦距为100 mm,F数为1.1,总长为107 mm,工作波段范围为8～12mm,引入一片二元衍射面实现无热化温度补偿功能。利用ZEMAX进行仿真设计,结果表明:在-40℃～+60℃温度范围内,系统奈奎斯特频率(30 lp/mm)处MTF均达到0.49,接近衍射极限。该系统具有焦距较长,相对孔径大、全视场像质优良、温度适应良好、二元面衍射效率高、易于加工和结构紧凑的特点。

Design of Long-wave Athermal Optical System Based on Binary Diffraction Surface

Using only three lenses, an infrared system matching 640×512 uncooled vanadium oxide long-wave focal plane detector was designed. The system has a focal length of 100 mm, an F-number of 1.1, a total length of 107 mm, and a working band range of 8-12μm. A binary diffraction surface was introduced to realize the non-thermal temperature compensation function. The simulation design using Zemax shows that the modulation transfer function (MTF)value at the Nyquist frequency (30 lp/mm) of the system reached 0.49 in the temperature range of -40℃-+60℃, which is close to the diffraction limit. The system has the characteristics of a long focal length, large relative aperture, good image quality in the full field of view, suitable temperature adaptation, high binary diffraction efficiency, easy processing, and compact structure.