宽光谱超大孔径反衍望远系统设计

Design of broad bandwidth reflective-diffractive hybrid telescope with super large aperture

二元光学元件具有许多传统光学元件无法比拟的优越性。利用2个二元光学元件作为系统的物镜和目镜,通过确定各元件的基本结构、孔径大小,设计了25 m的超大孔径反衍混合望远系统。所设计系统的弥散斑大小及MTF函数都能够达到设计要求。使用谐衍射透镜代替普通衍射透镜,对系统进一步改进,使望远系统获得了较宽的光谱范围。试验结果表明:改进后的系统无论在单一光谱、多频带光谱或者连续光谱范围,都能够获得接近衍射极限的成像质量。

Compared to conventional optics, binary optical elements have some unique advantages. A reflective and diffractive hybrid telescope with an aperture of 25 m was designed, with two binary optical elements as its objective and eyepiece. The dispersed spot size and MTF of the telescope meet the requirements. The high order diffractive lenses take the place of conventional diffractive lenses to improve the performance of the system, and the telescope achieves a broader bandwidth. The results show that the modified system can provide almost diffraction-limited imaging quality within the range of single-band, multi-band or continuous coverage.