折衍混合光学系统超宽温消热差设计

摘要

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 μm,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35μm、像元数320×240的非制冷红外焦平面阵列探测器.%A hybrid refractive/diffractive Petzval lens has been designed. Its working wavelength range is 3. 2-4. 5 μm, 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 320X240 and the pixel pitch of 35 μm