折衍混合光学系统超宽温消热差设计

利用折衍混合结构设计了超宽温范围内的光学被动式消热差Petzval物镜，系统工作波段为3.2～4.5 m，视场角为8.42，焦距为95 mm，后工作距为60.5 mm。使用锗和硅两种材料，引入了2个非球面和1个衍射面, 实现了消热差和结构简单轻量化，该系统在－80～200 ℃范围内, 调制传递函数(MTF) 优于0.7，接近衍射极限, 成像质量良好，该系统适用于像元尺寸为35 m、像元数320240的非制冷红外焦平面阵列探测器。

Wide-temperature-range athermalization for MWIR hybrid refractive/diffractive optical system

A hybrid refractive/diffractive Petzval lens has been designed. Its working wavelength range is 3.2-4.5 m, full field of view is 8.42, efficient focal length is 95 mm and back focal length is 60.5 mm. The Petzval lens consists of four lenses, including two aspheric surfaces and a diffractive surface, which make the Petzval lens compact and light. Its modulation transfer function is above 0.7 in the temperature range from -80 to 160 ℃. The Petzval lens is compatible with the uncooled staring focal plane array which has a format of 320240 and the pixel pitch of 35 m.