衍射元件在大相对孔径红外镜头中的应用

Application of Diffractive Elements to Infrared Lenses of High Relative Aperture

针对非制冷红外探测器的光学成像系统F／#-1左右的要求，分别采用三片式、两片式折射物镜为初始结构，结合像差理论，设计出了三款f=50mm，F／1，全视场角为10°，工作波段为8～12μm的红外物镜．前两款为折射物镜，后一款为折-衍混合物镜．设计结果表明：非球面和衍射面结合的折衍混合物镜可以替代传统的球面物镜，性能上也优于采用非球面的折射结构物镜．

The requirement for the optical imaging system of the uncooled infrared detector is about F/ # = 1. To meet this requirement,two-element and three-element refractive lenses are adopted as the initial configurations,three kinds of lenses,which have parameters：f=50 mm,F/1,full FOV=10°,operat ing wavelength range is 8-12μm, are designed according to abervation theory The former two are refractive lenses, the latter one is a refractive-diffractive hybrid one. The design result indicates that the refractive-diffractive hyhrid lens with aspherical and diffractive elements can replace the traditional spherical lens,and is more excelled than the refractive lens with aspherical elements in performance.