用平凸透镜制作大口径光栅的像差分析

Wavefront aberration analyse of large-aperture grating fabricated by piano-convex lens

分析使用两个对称的单平凸透镜光路制作光栅并用MATLAB编写光线追迹程序分析了所制作的光栅的衍射波像差的特点,经计算得出在较小焦比D/F情况下其衍射波像差仅与两支光路点光源的调节偏差之差有关与单独的各个偏差无关;初级像差中球差很小几乎可忽略:彗差仅与垂轴调节偏差之差成线性关系;像散仅与轴向调节偏差之差成正比;且当平凸透镜的焦比D/F增大时,各像差项迅速增大。点光源调节偏差一致时的衍射波像差随着系统的焦比D/F增大而迅速增大,并分析了当透镜的焦比D/F一定时,透镜的焦距与所制作的光栅的空间频率对衍射波像差的影响。

Using two symmetrical piano- convex lens system to fabricate grating was analyzed and the characteristic of diffraction wavefront aberration of the grating was summarized by ray tracing program using MATLAB software. Through calculating when the focal ratio D/F is small the diffraction wavefront aberration only have relation with the difference between the adjusting errors of the two point source of the optical system and is independent of any single adjusting error; in the primary aberration the spberieal aberration is small and almost can be neglected; the coma aberration is linear relation with the difference of adjusting errors in the vertical axis direction; the astigmatic aberration is proportional with the difference of adjusting errors in the axis direction;these aberrations increase swiftly as the focal ratio D/F increase. When the difference of adjusting errors is zero the diffraction wavefront aberration also increase swiftly as the focal ratio D/F increase, and the effect on diffraction wavefront aberration caused by the focal length of the lens and the spatial frequency of the grating was presented under the condition the focal ratio D/F is a constant.